Beyond the Garden Basics

In today’s “Beyond the Garden Basics” podcast, we talk with Douglas Kent, author of “Firescaping: Protecting Your Home with A Fire-Resistant Landscape”. He has a slightly different view of thwarting home and yard damage for residents of the urban-wildland interface, who are increasingly keeping a wary eye - and nose - in the air for smoke. And as we pointed out in the Garden Basics with Farmer Fred podcast this week (Ep. 235), in our chat with University of California Fire Advisor Luca Carmignani, it is the threat not so much from flames creeping onto your property as it is blowing, burning embers hurtling towards

your house from a wind-driven wildfire. Those embers (or “firebrands”) can travel a half mile or more from the actual fire itself, whose ferocity is supercharged by winds that can reach 60 miles per hour or more. And it’s not just California. States throughout the West, Northwest, Southwest, intermountain west, and the South have been hit by massive wildfires, that the Washington Post estimates that 16% of all Americans - on 80 million properties - face the threat of wildfire.

Wildfires remain a danger across California and much of the unusually dry Western United States, as there’s still plenty of time this fall for grass, woody debris, and other flammable materials to become dry and ignite, threatening homes adjacent to wildfire-prone areas with flying, embers. We are all hopeful that we will have a wet or snowy winter sooner, rather than later. In the meantime, the University of California has advice on prepping your home and landscape to slow the destruction in case of a wind-blown wildfire.

"The smaller the fuels – pine needles, grass, and small twigs – the faster they can dry out, meaning they will be ready to burn again a few days or weeks after a large rainstorm," said Susie Kocher, a UC Cooperative Extension forestry and natural resources advisor for the Central Sierra.

When it comes to essential wildfire preparations in this age of drought, not every project requires a bank-breaking budget and an army of contractors.

There are small – but significant – home and landscaping improvements that most people can complete by themselves during a weekend or two, with a quick run to the hardware store and some basic planning and safety precautions.

"There are a lot of factors that play into your home’s vulnerability to ignition; small changes and upgrades can help reduce some of that risk for people living in high wildfire risk areas," Kocher explained. "The bigger projects like replacing windows and roofs are very important, but there are definitely smaller projects that people can tackle right away at lower cost that also reduce risk. The main goal of these actions is to reduce the risk that wildfire embers can ignite your home."

Kocher recommends these measures as simple but crucial ways to bolster your home’s wildfire resiliency.

• Let’s start with what may be the most difficult task to accomplish. Not because it is dangerous, but because of reluctance: taking out all vegetation and wood chip mulch within five feet of your home. Creating defensible space immediately next to your home is a top priority, so be sure there’s nothing combustible within this primary zone. Plants, mulch, woodpiles, wicker furniture or anything that can catch fire should be removed.

• And now for the more precarious task: removing debris from your roof. Because of its expansive surface, the roof is the most susceptible area of your house to embers. Removing accumulated leaves and needles is especially important if you have a complex roofline with dormers or other elements – that’s where embers gather, too, and could ignite flammable siding. And while you’re up there, give those gutters a good cleaning. Or, if you and the outdoor ladder are not on friendly terms anymore, hire a gutter cleaning service who can also blow debris off the roof.

• Install metal flashing in vulnerable spots. Replacing all your siding with noncombustible material can be pricey, but a more manageable task would be adding corrosion-resistant metal flashing to select areas: roof-to-wall intersections, the place where the chimney comes out of the roof, and the edge where the deck meets the house.

• Remove debris from between the boards of your deck and fence as well as below your porch. Embers can ignite leaves and needles stuck between the boards, so be sure to keep those gaps clean and clear.

• Inspect vents and upgrade to finer mesh screens. Install or swap in noncombustible, corrosion-resistant metal mesh screening that is at least 1/8" mesh. 1/16" would be even better. However, that requires more frequent maintenance. These screens help prevent embers from entering your attic and crawl space. In addition, put together some vent covers that can be deployed if you have time before a wildfire arrives.

More information and more fire-related links are available at the University of California Ag and Natural Resources webpage, “Wildfire Preparedness in the Home Landscape”.

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

America’s Favorite Retired College Horticulture Professor, Debbie Flower, discusses garden chemical safety, including: when organic controls can be hazardous; the dangers of homemade pesticides; how to check for organic ingredients in a pesticide product; and, ways to determine if your organic garden “inputs” (water, mulches, manures) are safe to use.

Despite your best organic efforts, this CDC study says there’s a high chance that glyphosate is probably in your urine:

Here’s the background on one statement in that podcast: that there might be glyphosate in your urine:

“…more than 80 percent of urine samples drawn from children and adults participating in a US health study contained a weedkilling chemical linked to cancer and other health problems. The June 30 report by a unit of the Centers for Disease Control and Prevention (CDC) found that out of 2,310 urine samples collected, 1,885 were laced with detectable traces of glyphosate, the active ingredient in herbicides sold around the world, including the widely used Roundup brand.”

Sources For Water Testing:

National Testing Laboratories: https://watercheck.com

Water Testing Accredited Laboratories in California: https://www.calwater.com/waterquality/water-quality-testing-labs/

Source for Organic rice straw: Brokenbox Ranch, Williams, CA

From Clemson University: “Less Toxic Insecticides”:

Factsheet | HGIC 2770 | Updated: Aug 27, 2021 |

While a good pest management plan will start with preventative, cultural, and other non-chemical methods, these are sometimes not completely effective on their own. In this case, a pesticide may be considered. If pesticide use is deemed necessary for control of the pest problem, it is good practice to use the least toxic pesticide that will do the job effectively. Although all pesticides are by their nature toxic in some way to some organisms, there are now a number of “less toxic” pesticide options.

Insecticides may be considered less toxic for several reasons. Generally, they should pose less risk to human and environmental health than conventional insecticides. Many break down rapidly and do not accumulate in the body or environment. Some are very pest specific and do little or no damage to other organisms. Still, others, such as bait stations, minimize human exposure to the pesticide.

While “organic” insecticides are often less damaging to the environment than conventional insecticides, they are still pesticides. All pesticides should be evaluated before selection for level of toxicity, effectiveness, environmental impacts, and costs. Some “organic” or natural pesticides are as toxic, or even more toxic, than some synthetic pesticides. All pesticide products have a toxicity signal word on the label, which will be “caution”, “warning”, or “danger”. Choose the products with “caution” on the label, as they are least apt to harm the user and the environment.

Soaps & Oils

Insecticidal soaps and oils have a number of advantages for controlling insects. They are virtually non-toxic to humans and other mammals and are relatively safe to beneficial insects in the landscape. They control a wide range of common soft-bodied pests, including aphids, mealybugs, thrips, whiteflies, mites, and scales. It is difficult for pests to develop resistance to oils and soaps. Soaps and oils are now readily available and relatively inexpensive.

Both soaps and oils can cause damage to plants if applied when plants are water-stressed, temperatures are above 90 °F, sprayed in direct sunlight, or when high humidity prevents rapid drying. Some plants are sensitive to oil or insecticidal soap sprays. See sensitive plant lists in HGIC 2771, Insecticidal Soaps for Garden Pest Control. Read and follow the label.

Since soaps and oils work on contact, an effective application must coat both the upper and lower leaf surfaces as well as stems for best results. Repeated applications may be necessary. Apply soap or oil sprays in the early morning or late evening to reduce drying times for more effective insect pest control.

Insecticidal Soaps: Insecticidal soaps kill by suffocation; additionally, they damage the protective coat of soft-bodied insects, causing them to dehydrate.

Homemade soap recipes are not recommended because they may be more likely to cause foliage burn. Commercial insecticidal soaps are tested on plants and are less likely to cause damage. Some are available as concentrates to dilute before spraying, and some are available as pre-mixed Ready to Use (RTU) bottles. Examples of insecticidal soap products are:

* Bonide Insecticidal Soap RTU

* Espoma Organic Insect Soap RTU

* Garden Safe Insecticidal Soap Insect Killer RTU

* Miracle-Gro Natures’s Care Insecticidal Soap RTU

* Natria Insecticidal Soap RTU

* Natural Guard Insecticidal Soap Concentrate

* Safer Brand Insect Killing Soap Concentrate

* Whitney Farms Insecticidal Soap RTU

Horticultural Oils: Oil products smother soft-bodied insects on contact. Oils are formulated as either horticultural or dormant oils. Dormant oils are heavier, less refined oils used on dormant, leafless plants to control overwintering insects (e.g., aphids, spider mites, and scales). Dormant oils will damage plant foliage if used during the growing season. Horticultural oils are also called summer or superior oils, and these are lighter and more refined. They can be applied to both actively growing plants as well as dormant plants for insect pest control. Do not apply horticultural oil sprays when the temperature is above 90 °F, below 45 °F, or if rain is in the forecast within 24 hours.

Most horticultural oils are applied at a 1 to 2% mix with water to spray actively growing plants (this would be 2½ to 5 tablespoons of oil with a gallon of water). To use horticultural oil as a “dormant oil” spray to control pests on woody plant bark, they are mixed at 4% with water (this would be 10 tablespoons of oil per gallon of water). Always spray very late in the day to slow drying time and to get better insect control. Most are available as concentrates made to dilute with water in a sprayer, although some are available as either a Ready to Spray (RTS), which is a bottle to attach to a garden hose for spraying, or as a Ready to Use (RTU), which is a pre-mixed spray bottle. Examples of horticultural oils are:

* Bonide All Seasons Spray Oil Concentrate; & RTS; & RTU

* Ferti-lome Horticultural Oil Spray Concentrate; & RTS

* Monterey Horticultural Oil Concentrate; & RTS; & RTU

* Safer Brand Horticultural & Dormant Spray Oil Concentrate

* Southern Ag Parafine Horticultural Oil (concentrate)

* Summit Year Round Spray Oil Concentrate

Sesame Oil: Sesame oil sprays work in the same manner as horticultural oils. Follow label directions for mixing and use.

* Organocide Bee Safe 3-in-1 Garden Spray Concentrate; RTS; & RTU

Botanical Insecticides

Botanical insecticides are naturally occurring toxins extracted from plants. There are several advantages to using botanical rather than synthetic insecticides. Plant derived insecticides break down quickly in the environment, resulting in little risk of residues on food crops and less risk to beneficial insects. Some materials can be used shortly before harvest. Most botanicals are rapid acting, and most, but not all botanicals are of low to moderate toxicity to mammals. Most botanical insecticides must be eaten by the insect pest. Therefore, they are primarily harmful to these pests and do little harm to beneficial insects.

There can also be disadvantages to using these products. Rapid breakdown, while less risky to health and environment, often creates a need for precise timing or more frequent applications. Several botanical insecticides are quite toxic and should be handled accordingly. Some botanical insecticides can be difficult to find in local stores.

Neem products: Neem oil is a botanical insecticide made from extracts of Neem tree seeds. The active ingredient is listed on product labels as clarified, hydrophobic extracts of neem oil. It is used to control a wide variety of insects, including leafminers, whiteflies, thrips, caterpillars, aphids, mealybugs, spider mites, scale crawlers, and beetles. Neem oil is most effective against actively growing immature insects. Neem oil sprays kill small insect pests and mites by suffocation, as do horticultural oil sprays, but also have some insecticidal properties. Neem oil sprays have some fungicidal activity, but it is typically limited to powdery mildew control. This control is primarily because it is an oil. However, a horticultural oil spray generally works better for powdery mildew control.

Azadirachtin, the active ingredient in neem extracts, has a very low mammalian toxicity. It has been separated from the neem oil. It is a somewhat effective insect feeding deterrent and growth regulator. Azadiractin does not produce a quick knockdown and kill but stops insect feeding. The treated insect usually cannot molt into its next life stage and dies without reproducing. It also is an egg-laying deterrent.

Many commercial neem products exist, and these products are labeled for use on ornamentals, foliage plants, trees, shrubs, and food crops. Most neem oil products are available as concentrates made to dilute with water in a sprayer, but some are available as either Ready to Spray (RTS), which is a bottle to attach to a garden hose for spraying, or as Ready to Use (RTU), which is a pre-mixed spray bottle. Examples of neem products for landscape and garden use include:

Neem Oil:

* Bonide Rose Rx 3-in-1 Concentrate; & RTU

* Bonide Neem Oil Concentrate; & RTU

* Concern Garden Defense Multi-Purpose Spray Concentrate

* Espoma Organic Neem Oil 3-in-1 RTU

* Ferti-lome Rose, Flower & Vegetable Spray Concentrate

* Garden Safe Fungicide 3 Concentrate; & RTU; & RTS

* Garden Safe Neem Oil Extract Concentrate

* Monterey 70% Neem Oil Fungicide/Insecticide/Miticide Concentrate; & RTS

* Natria Neem Oil Concentrate; & RTU

* Natural Guard Neem Concentrate

* Safer Brand Neem Oil Concentrate; & RTU

* Southern Ag Triple Action Neem Oil Concentrate

Some neem oil products also contain the botanical insecticide pyrethrin. Examples are:

* Bonide Bon-Neem II Concentrate

* Ferti-lome Triple Action Plus II with Neem Oil

* Ferti-lome Fruit Tree Spray Concentrate

* Monterey Fruit Tree Spray Plus RTS

* Monterey Rose & Flower Spray Plus RTS

* Ortho Tree & Shrub Fruit Tree Spray Concentrate

Azadiractin:

* Amazin 1.2% Plus

* Aza-Direct Botanical Insecticide

* AzaGuard Botanical Based Insecticide/Nematicide

* AzaMax Botanical Insecticide

* AzaPro

* AzaSol Non-oil Based, Water Soluble Powder

* Azatin O Biological Insecticide

* Azera Gardening (with Pyrethrins)

* Biosafe Insect Control

Limonene (also known as d-Limonene) is produced from citrus oils extracted from oranges and other citrus fruit peels. It is used as a contact insecticide against ants, roaches, palmetto bugs, fleas, silverfish, and many other insects. Limonene has low oral and dermal toxicity to mammals, birds, and fish, although it can cause skin irritation or sensitization in some people. Limonene is not used for insect pest control on plants, as this active ingredient may cause significant plant injury. Several natural herbicide products contain d-limonone for weed control.

Pesticide products containing d-limonene are available for indoor insect control, such as in Orange Guard Home Pest Control Insect Killer Concentrate & RTU.

Capsaicin is the material that makes chili peppers hot. It can be used on ornamentals outdoors and indoors for control of aphids, spider mites, thrips, whitefly, lace bugs, leafhoppers, and other pests. It is important to note that capsaicin-containing products are primarily used to repel insects rather than to kill existing infestations, and they also appear to be effective at repelling certain animal pests, such as rabbits, deer, and squirrels. Homemade hot pepper sprays can be made for insect pest control on plants. Products containing capsaicin as an animal repellent include:

* Bonide Hot Pepper Wax Animal Repellent RTU,

Pyrethrin: Pyrethrum is made from the finely powdered flowers of a species of daisy. The word pyrethrum is the name for the crude flower dust itself, and the term pyrethrin refers to the insecticidal compounds that are extracted from pyrethrum. Pyrethroids are not botanical insecticides but synthetically produced pesticides that are very similar in structure to pyrethrins. They are stronger and last longer on plants for pest control.

Pyrethrin is a contact insecticide and must be applied directly to the insect to be effective. Pyrethrin rapidly paralyzes pests but may not kill them. However, pyrethrins are often formulated with another insecticide to ensure that paralyzed insects do not recover and once again become pests.

Because the pyrethrin mammalian toxicity is very low, it can be applied to food crops close to harvest. Pyrethrin has high contact toxicity for common beneficial insects., but its insecticidal activity only lasts a few hours. There are many products with pyrethrin available; some products contain pyrethrin alone, and other products are combined with another insecticide, such as in the lists below.

Pyrethrins:

* PyGanic Crop Protection EC 1.4 (1.4% a.i.) OMRI,

* PyGanic Crop Protection EC 5.0 (5.9% a.i.) OMRI.

* Monterey Bug Buster – O (1.4% a.i.) OMRI

Pyrethrins & Neem Oil:

* Ferti-lome Triple Action Plus II with Neem Oil Conc.; & RTU

* Ferti-lome Fruit Tree Spray Concentrate (with pipernyl butoxide),

* Bonide Bon-Neem II Concentrate (with pipernyl butoxide),

* Ortho Tree & Shrub Fruit Tree Spray Concentrate.

Pyrethrins & Pipernyl Butoxide:

* Southern Ag Natural Pyrethrin Concentrate,

* Garden Safe Rose & Flower Insect Killer RTU,

* Garden Safe Multi-purpose Garden Insect Killer RTU

Pyrethrins & Sulfur:

* Bonide Captain Jack’s Orchard Spray Concentrate; & RTS,

* Bonide Tomato & Vegetable 3 in 1 & RTU

* Ortho Insect, Mite & Disease 3-in-1 RTU

* Natria Rose & Flower Insect, Disease & Mite Control RTU

* Natria Insect, Disease & Mite Control RTS; & RTU

Pyrethrins & Canola Oil:

* Monterey Take Down Garden Spray Concentrate; & RTU

* Whitney Farms Outdoor Insect Killer RTU,

* Espoma Organic Insect Control RTU

Garlic is marketed in several products intended to repel insects, much as capsaicin does. Products are labeled to repel a wide variety of pests on ornamental plants, but garlic may also repel nuisance animals. To date, there is limited research showing the effectiveness of garlic insecticides. Products containing garlic or garlic oil include:

* Havahart Critter Ridder Deer, Rabbit & Squirrel Repellent Concentrate (with putrescent egg solids & capsaicin)

* Captiva Insect Repellent/ Insecticide (with capsicum & soybean oil)

Rotenone, Sabadilla, Ryania, and Nicotine are older botanical insecticides that are no longer available due to toxicity to people and/or the environment. Although these insecticides were naturally derived, they are more toxic or harmful than many commercially produced insecticides.

Essential Oils

A variety of pesticides based on essential oils or components of essential oils have come on the market in the last few years. Essential oils are volatile, highly concentrated substances extracted from plant parts. In 1996 the EPA established that certain ingredients that pose minimum risk to users no longer require EPA approval to be marketed as insecticides. A number of these ingredients are essential oils, including the oils of geranium, cedar, cinnamon, citronella, citrus, clove, eugenol (a component of clove oil), garlic, mints, rosemary, thyme, and several others. As insecticides, these work most commonly as contact-killing agents only, so re-treatment may be needed. Most essential oils used as pesticides work by disrupting an insect neurotransmitter that is not present in people, pets, or other vertebrates.

Examples of brands that make essential oil insecticides for insect pest control within homes are included below, but check the label for ingredients first.

* Wondercide

* Dr. Earth

* Cedarcide

* Essentia

* Maggie’s Farm

* Aunt Fannie’s

* Monterey

* Some Ortho Home Defense products

Microbial Insecticides

Microbial insecticides contain microorganisms (viruses, bacteria, fungi, protozoa, or nematodes) or their by-products. Microbial insecticides are especially valuable because their toxicity to animals and humans is extremely low.

Insecticidal products comprised of a single species of microorganism may be active against a wide variety of insects or group of related insects (such as caterpillars), or they may be effective against only one or a few species. Most are very specific. Since there is such a narrow range of insects killed, they spare the beneficial insects almost entirely.

Bacillus thuringiensis products are the most widely used microbial insecticides in the United States. They are commonly known as Bt. Different subspecies of Bt are effective against different groups of insects or their larvae.

The best results will be achieved using Bt products by following a few guidelines.

* Make sure the Bt product you have chosen lists the specific insect you want to control.

* Make sure the insect is at a stage where it is susceptible to control by Bt. In general, Bt products are effective against young larval stages but will not kill adults.

* Spray the parts of the plant on which insects are feeding thoroughly, including the underside of leaves. Bt products must be eaten in order to be effective. Liquid formulations are more effective and stay on plants better than dust formulations.

* Treat with Bt in the late afternoon or evening or on a cloudy day as Bt breaks down in sunlight.

* Be aware that Bt does not kill immediately, but the poisoned insects will stop feeding almost immediately.

Bacillus thuringiensis var. kurstaki (Btk) products are toxic only to larvae of butterflies and moths. They are used to safely control many common leaf-feeding caterpillars, including caterpillar pests on vegetables, bagworms and tent caterpillars on trees and shrubs, and European corn borer larvae. Some caterpillars are not effectively controlled by Bt, especially those that live in the soil or bore into plant tissues without consuming a significant amount of the Bt applied to plant surfaces. Liquid Bt products are frequently referred to as Thuricide, and Bt dust products are often referred to as Dipel.

Bacillus thuringiensis var. kurstaki products include:

* Bonide Thuricide Bt Concentrate

* Garden Safe Bt Worm & Caterpillar Killer Concentrate

* Monterey Bt Concentrate; & RTU

* Natural Guard Caterpillar Killer Spray with Bt Concentrate; & RTU)

* Safer Brand Caterpillar Killer Concentrate

* Southern Ag Thuricide Bt Caterpillar Control Concentrate

* Tiger Brand Worm Killer Concentrate

* Ferti-lome Dipel Biological Insecticide Dust

* Safer Brand Garden Dust with Bt

* Southern Ag Dipel Dust

Bacillus thuringiensis var. israelensis (Bti) formulations kill mosquito, black fly, and fungus gnat larvae. Bti is most effective for mosquito or black fly control when it is used on a community-wide basis. For most homeowners, eliminating standing water sources is more effective than applying Bti or other insecticides. Floating products sold as dunks or pellets can eliminate mosquito larvae in ornamental ponds and other areas that cannot be drained. Bti products that are available commercially include:

* Summit Mosquito Dunks,

* Summit Mosquito Bits,

* Microbe-Lift Biological Mosquito Control (granules & liquid)

Milky Spore products contain the naturally occurring bacterium Paenibacillus popillae. These products are applied to turf and watered into the soil below to control the larval (grub) stage of the Japanese beetle, and less effectively, some other beetle grubs. If a substantial grub population is present at the time of application, milky spore can survive beneath undisturbed sod for a period of 15 to 20 years. Consequently, lawn applications of milky spore bacteria might not have to be repeated each year.

Examples of products are:

* St Gabriel Organics Milky Spore Powder Japanese Beetle Control

* St Gabriel Organics Milky Spore Granular Grub Control

Spinosad is an insect toxin derived from a soil-dwelling bacterium. It kills primarily by ingestion and is used against fire ants, caterpillars, thrips, leaf miners, and some beetles. It is also used against caterpillar borers of fruit trees. When applied at recommended rates, this product poses less risk than most insecticides to mammals, birds, fish, and beneficial insects. It is, however, toxic to bees and should not be applied to plants in flower. Affected pests stop feeding within minutes but may remain on the plant for up to two days. Always spray plants late in the day to reduce any harmful effects on pollinating insects.

Products containing spinosad are sold as concentrates to spray or as fire ant baits in granular form. The sprays are labeled for use on ornamentals, lawns, and vegetables; the baits can be used in landscapes and within vegetable gardens. Examples of concentrates and baits are:

Spinosad Concentrates:

* Bonide Colorado Potato Beetle Beater Concentrate,

* Bonide Captain Jack’s Deadbug Brew Concentrate; & RTU,

* Ferti-lome Borer, Bagworm & Leafminer Spray Concentrate,

* Monterey Garden Insect Spray Concentrate,

* Natural Guard Spinosad Landscape & Garden Insecticide RTS,

* Southern Ag Conserve Naturalyte Insect Control Concentrate.

Spinosad Fire Ant Baits:

* Conserve Fire Ant Bait,

* Ferti-lome Come and Get It! Fire Ant Bait,

* Southern Ag Payback Fire Ant Bait,

* Terro Fire Ant Bait Mound or Broadcast Treatment.

Beauveria bassiana is a naturally occurring fungus that attacks and kills a variety of immature and adult insects. Insects effected by various formulations include whiteflies, aphids, mites, caterpillars, leaf hoppers, grasshoppers, Colorado potato beetles, Mexican bean beetles, Japanese beetles, boll weevils, cutworms, sod webworms, bark beetles, chinch bugs, fire ants, European corn borers, and codling moths. Beneficial insects, such as lady beetles, are also susceptible.

Products containing Beauveria work best when applied at the onset of an infestation. Thorough spray coverage is essential because fungal spores must contact the insect for infection to occur. Then it typically takes three to seven days after application for the spores to germinate, penetrate, and grow throughout the insect, thus killing them.

Examples of Commercial products containing Beauvaria include:

* Naturalis L (liquid)

* BioWorks Botanigard 22WP (wettable powder)

* BioWorks Botanigard ES (liquid)

* BioWorks Botanigard Maxx (with pyrethrins; liquid)

* Mycotrol WPO (wettable powder)

* Mycotrol ESO (liquid)

* BioSolutions BB Fix (wettable powder)

Beneficial Nematodes Nematodes are microscopic, worm-like parasites. While some species of nematodes are pests of turfgrass and other plants, others are beneficial, being parasites of harmful insects. Since beneficial nematodes cannot develop in vertebrate animals, they are very safe for use in pest control.

Beneficial nematodes can be used to control a variety of plant pests, including larvae of black vine weevil, clearwing borers, cutworms, sod webworms, mole crickets, and white grubs. It is important to select the proper nematode species when trying to control a particular pest.

Nematodes can be difficult to use for most home gardeners. They must be shipped, stored, and used under specific temperature and moisture conditions and generally must be used very soon after shipping. For this reason, they are best ordered from suppliers immediately after a pest problem is observed.

A number of nematode products are available by mail order. Be sure the product you are ordering is specified for the pest you have and that you are able to provide proper environmental conditions for the nematodes. In general, nematodes require moist conditions, high humidity, and temperatures between 55 and 90 °F with little direct sunlight.

Minerals

Diatomaceous Earth is a non-toxic powder composed of fossilized, one-celled organisms called diatoms. It is used to control slugs, millipedes, sowbugs, cockroaches, ants, and soft-bodied insects like aphids. It has low mammalian toxicity. Use the “natural grade,” not the type used as a filtering agent in swimming pools.

Prolonged exposure to diatomaceous earth will irritate the lungs and other tissues of people or pets. Because it also kills honeybees, avoid applying the product to crops in flower. Diatomaceous earth products include:

* Bonide Diatomaceous Earth Crawling Insect Killer,

* Garden Safe Crawling Insect Killer Diatomaceous Earth,

* Harris Diatomaceous Earth Crawling Insect Killer,

* Natural Guard Crawling Insect Control Containing Diatomaceous Earth,

* Safer Brand Ant & Crawling Insect Killer,

* St Gabriel Organics Insect Dust Diatomaceous Earth.

Kaolin Clay products act as a barrier that irritates insects and disguises the host plant by coating it with a ghostly white film. Insects are apparently unable to recognize plants treated with kaolin. It is most commonly used against a wide variety of pests on apple and pear trees. In addition, kaolin can be used to control Japanese beetles, tarnished plant bugs, thrips, leafhoppers, cucumber beetles, and Colorado potato beetles on vegetable crops. Kaolin must be applied as a preventative to be effective and cannot control a pest that is already established.

Kaolin clay can be applied up to the day of harvest and is non-toxic. Kaolin is sold as Surround. Examples of products are:

* Gardens Alive Surround Broad Spectrum Sun & Insect Crop Protectant

* Nova Source Surround WP

Boric Acid is derived from boron, a naturally occurring mineral. It acts as a stomach poison and causes insects to die from starvation. Boric acid is available in powder, paste, aerosol, tablet, and liquid forms for use against cockroaches, ants, and other insects. It should not be applied around plants in the landscape because, although boron is a necessary plant micro-nutrient, larger than trace amounts are toxic to plants. Most boric acid products are available as ready-to-use products. Boric acid (labels may list this as orthoboric acid or sodium tetraborate) is sold under a number of brand names, and product examples include :

* Avenger Boric Acid Roach Killer II (powder)

* Bonide Boric Acid Roach Killer (powder)

* Hot Shot Maxattrax Roach Killing Powder with Boric Acid

* Terro Multi-Purpose Insect Bait

* Zap-A-Roach – Roach & Ant Killing Powder

* Zone Defense Kills Roaches with Boric Acid (powder)

Silica Gel is an inert, nonabrasive material that is very effective in absorbing moisture. It absorbs the waxy coating on the insect’s body and causes death by dehydration. Silica gel products are often used by professional pest control operators to control cockroaches, silverfish, and other pests. Examples are:

* PT Tri-Die Aerosol,

* CimeXa Insecticidal Dust, and

* Bayer Drione Insecticide (dust).

These contain amorphous silica gel.

Sulfur is probably the oldest known pesticide in current use. It can be used as a dust, wettable powder, or liquid and is primarily for disease control. However, mites, psyllids, and thrips are also controlled by sulfur. Sulfur is non-toxic to mammals but may irritate skin or especially the eyes. Sulfur is also used as a fungicide to control powdery mildew, rusts, brown rot, and leaf spots on fruits, vegetables, and ornamentals.

Sulfur has the potential to damage plants in hot, dry weather. It is also incompatible with other pesticides. Do not use sulfur within 20 to 30 days of applying spray oils to plants as it reacts with the oils and is more likely to cause damage to foliage. Do not apply sulfur when temperatures are above 80 °F. Examples of products containing sulfur are:

Sulfur:

* Hi-Yield Wettable Dusting Sulfur,

* Safer Brand Garden Fungicide Concentrate; & RTU OMRI,

* Southern Ag Wettable or Dusting Sulfur,

* Bonide Sulfur Plant Fungicide (dust or spray),

Sulfur & Pyrethrins:

* Bonide Captain Jack’s Orchard Spray Concentrate; & RTS,

* Bonide Tomato & Vegetable 3 in 1 & RTU

* Natria Rose & Flower Insect, Disease & Mite Control RTU

* Natria Insect, Disease & Mite Control RTS; & RTU

* Ortho Insect, Mite & Disease 3-in-1 RTU

Sulfur with Insecticidal Soap:

* Safer Brand 3-in-1 Garden Spray Concentrate OMRI.

* Safer Brand Rose & Flower 3-in-1 Garden Spray RTU OMRI

* Safer Brand Tomato & Vegetable 3-in-1 Garden Spray RTU OMRI

Insect Growth Regulators

Insect growth regulators (IGRs) are juvenile insect hormone analogs. They interfere with egg development and molting of various insect life stages. Because of their mode of action, they are very safe for vertebrate animals. IGRs are among the safest pesticides for application in homes. They are primarily used in homes for flea control. More information is available in HGIC 2423, Flea Control.

Two commonly available IGRs are methoprene (Precor) and pyriproxyfen (Nylar). The latter is photostable, and therefore can also be used outdoors. Nylar is sold as Martin’s IG Regulator.

Safer Formulations

Bait Stations deliver an insecticide through a sealed plastic or metal chamber that insects enter. This gives bait stations the advantage of decreasing both the amount of insecticide used and the likelihood of exposure to it. Bait stations are particularly suitable for use in situations where the safety of children and pets is a concern or in areas where food is prepared or stored.

Numerous brands of bait stations are commonly available to control cockroaches and ants. Some of the more effective bait stations have fipronil as the active ingredient, but those with boric acid (it may list this as orthoboric acid or sodium tetraborate) or hydramethylnon are also available. Each company below has a variety of baits stations and gels. Examples of products are:

* Terro Liquid Ant Bait,

* Combat Source Kill Max Ant Bait,

* Bayer Maxforce FC Ant Bait Stations,

* Combat Roach Killing Bait,

* Bayer Maxforce FC Magnum Roach Killer Bait Gel.

Pesticide Safety

Always read the pesticide label and follow its directions exactly. You may only use the pesticide on sites or crops listed on the label. Be sure to observe all special precautions that are listed on the label. Wear protective clothing or equipment as listed on the label when mixing or applying pesticides. Mix pesticides at the rate recommended for the target site as listed on the label. Never use more than the label says. Follow all label directions for safe pesticide storage and disposal. Always remember to read and heed the six most important words on the label: “KEEP OUT OF REACH OF CHILDREN.”

Caution: Pollinating insects, such as honey bees and bumblebees, can be adversely affected by the use of pesticides. Avoid the use of spray pesticides (both insecticides and fungicides), as well as soil-applied, systemic insecticides unless absolutely necessary. If spraying is required, always spray late in the evening to reduce the direct impact on pollinating insects. Always try less toxic alternative sprays first for the control of insect pests and diseases. For example, sprays with insecticidal soap, horticultural oil, neem oil extract, spinosad, Bacillus thuringiensis (B.t.), or botanical oils can help control many small insect pests and mites that affect garden and landscape plants. Neem oil extract or botanical oil sprays may also reduce plant damage by repelling many insect pests. Practice cultural techniques to prevent or reduce the incidence of plant diseases, including pre-plant soil improvement, proper plant spacing, crop rotation, applying mulch, applying lime and fertilizer based on soil test results, and avoiding overhead irrigation and frequent watering of established plants. Additionally, there are less toxic spray fungicides that contain sulfur or copper soap and biological control sprays for plant diseases that contain Bacillus subtilis. However, it is very important to always read and follow the label directions on each product. For more information, contact the Clemson Extension Home & Garden Information Center.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

Growing Citrus Trees Indoors

Here in California, or if you live in Arizona or Texas or Florida, you get to grow citrus in your backyard, year round. For most of the rest of the nation, though, that would be a challenge. A challenge to the point where maybe you have to bring it indoors for the winter. That could even be true here in California if you’re growing a citrus variety, such as lime trees, that can lose their fruit when the thermometer drops to 32 degrees, which happens here in the Central Valley on a regular basis. Maybe you have a really nice greenhouse to grow citrus. Combined with a heater to keep temperatures above 40, that would be ideal.

When it comes to tips for growing citrus, we turn to Lance Walheim, who has written several books about citrus. His titles include, “Citrus The Complete Guide to Selecting and Growing More Than 100 Varieties," and “All About Citrus and Other Subtropical Fruits.” He also was one of the contributing editors to the Sunset Western garden book that has a very good citrus section.

Walheim says indoor citrus growers need to choose the right varieties to be successful.

“I have met many people who have been growing  Meyer lemons and kumquats back East in very cold climates for 30-40 years, so people can be successful about it,” says Walheim. “But make sure you choose the right variety. I think you need to try growing citrus that is highly acidic. One of the best ones is the Meyer lemon tree. It's a very precocious tree that loves to bloom, and doesn't need a lot of heat to ripen. And it's a small tree so it can grows perfectly well in a container. All the kumquat hybrids, including Calamondins, are perfect for indoors. Also, they have smaller fruit that ripens quicker. And again, they have a propensity to rebloom often.” And despite the reputation of lime trees being very cold sensitive, Walheim says one lime variety, in particular, makes for a good household specimen. “Bearss lime is a good variety to try indoors,” says Walheim.

And what about the option of letting your citrus trees enjoy the warmer months outdoors and bringing them indoors for the winter? Is that viable? “It certainly is,” exclaims Walheim. “The key thing is to provide a transition zone, if moving it back and forth. When you're moving a citrus tree from indoors to outside in the late winter or early spring, or  from the outside to the indoor conditions in November or December in the Central Valley (or earlier in colder climates), you're really changing things for that tree. The humidity levels outside could be over 50-60%. You take it inside where the house is heated, you're dropping down to 10% humidity. So those are dramatic changes, and they're going to affect the tree as will the changing light conditions. So what I really recommend, whether you're going inside or outside as you provide a transition period, is to do it gradually.”

The process involves moving that tree every day for awhile, so make sure the plant is in a container that isn’t too big for you to move, perhaps 15 to 20 inches across at the top. Better yet, mount the container on a heavy duty small furniture dolly to roll the plant inside and out.

“If you're taking the tree outside, make sure it is in a shady spot during this transition period,  it may take several weeks,” says Walheim. Give them a shady condition several hours a day, and then move them back inside for the night. Move them to more outside light gradually.”

Walheim says the more critical transition is moving a containerized citrus tree to the indoors for the winter in colder climates. “You certainly don't want them next to a heater vent, you want to do whatever you can to increase the humidity, which means they can be placed on a tray with some rocks over it where you can add water to the base and increase humidity around the tree,” says Walheim. “Give them as much light as you possibly can. But what's going to happen, especially with a Meyer lemon, you're going to bring them indoors, and they're going to drop their leaves because of the lower humidity levels as less intense light. After that, the next thing that might happen is that they're going to bloom. The stress of all that it's going to make them bloom, so you're going to get some flowers, they probably won't set fruit indoors, but you will start getting some new growth. Make sure that you are doing a good job to maintain the water in the pot. Don’t overwater or underwater. And then they'll start to grow again.”

Other Tips from Walheim regarding growing indoor citrus:

• “They are widely adapted to soil types, so I think that most potting soils, the quality potting soils, are probably going to be okay. It's more important that we make sure we get those fertilizer nutrients into the soil.”

• “I would make sure I used a good citrus fruit food or another fertilizer that had the micronutrients in it of zinc, iron and manganese. But you are hoping that that tree is going to grow when it's inside unless you're totally shutting it down in a cold greenhouse. But I would fertilize lightly.”

• “You want to want to make sure that you water thoroughly, so the whole root ball gets wet. But you don't want that water sitting around in the basin. So whatever you can do to drain it out or put something in there to keep the soil out of the water constantly. The quickest way to kill a citrus tree is to have the bottom of that container continuously soaking wet. You're just not going to get the drainage, they need air for the roots.”

• “I know a lot of people that use supplemental lighting and get very good results. check around for the type of lights that you can get. Use lights especially if you're going to be growing your citrus trees in an area of the house where you're not getting enough light and they're a little out of the way.”

• “Leaf burn can be an issue, especially if you go into a dramatically drier area. And if you are not, if you've allowed salts to build up in the soil ball of the tree, and then you bring it inside, the lack of humidity is going to cause leaf burn and eventually leaf drop. I recommend before you bring the trees inside, do a preventative insect control spray of some kind, whether it's insecticidal soap or neem oil, whatever you're going to do, but also make sure you water the tree really well before you bring it inside. Let it sit out there and drain for a couple days and leach any salts that are in the soil out. That's a good practice with any house plant that you bring outside and then eventually bring indoors and watch the weather. Don't get caught with your tree outside before it gets too cold or if a late spring frost hits. Watch out for that. Get them inside if you have to.”

The University of Minnesota has more Indoor Citrus Growing Advice:

Growing and caring for your citrus plants

Growing citrus plants is not difficult if you can meet these requirements.

* Citrus plants grow best indoors with 65° days, dropping five to ten degrees at night.

* They need some direct sun for at least part of the day.

* During the summer, put citrus plants outside to take advantage of better growing conditions and extra light.

* Let the plants acclimate to sunny conditions by putting them in the shade of a tree or the north side of the house for the first several days.

* Make sure they have plenty of direct light once they're used to being outside.

* Get them used to lower light at the end of the summer by keeping them in a shady place for a week or so before bringing them back indoors.

Use the right potting mix and fertilizer

* Since citrus plants prefer acid conditions, use peat in the potting mix to help keep the pH down.

* Use about one-third sterile potting soil, one-third perlite or vermiculite, and one-third peat or other organic matter in the potting mix.

* Use a fertilizer made specially for acid-loving plants. Mix at half the recommended strength.

* Fertilize the plant only when it is actively growing, usually April through August or September.

Watch for pests

* Scale, whitefly and spider mites are some of the more common pests of citrus.

* Make sure the leaves are kept clean by periodically washing them, especially before you bring the tree inside for the winter.

* Pay special attention to the undersides as well as the tops of leaves.

* To treat insects, check garden centers for products currently approved for use on houseplants.

Pollinate for fruit

You may have flowers, but still have difficulty getting fruit to form on your citrus plant. This may be due to lack of pollination.

Insects pollinate citrus outside. Since these are not usually present in the home, shake the flowers gently or flick them with your fingers to spread pollen from flower to flower.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

Fresh Corn Soup (plus the cob)

Recipe by Andi MacDonald, Sacramento Co. Master Gardener and Professional Chef

Serves 4

During the dog days of summer, this soup is so refreshing served chilled. The secret ingredient is the corn stock, made from the corn cobs that generally get tossed. If corn is out of season, frozen can substitute and vegetable stock can be used instead of the corn stock. Perhaps not as good, but still pretty good!

2 tablespoons olive oil

4 ears of fresh corn, 2 cups altogether

1 cup onion, medium dice

½ cup carrots, medium dice

½ cup celery, medium dice

1 clove of garlic, minced

1 tablespoon fresh thyme, or 1 teaspoon dried

6 cups corn stock (or vegetable stock, unsalted if possible)

1 teaspoon salt, or to taste

½ teaspoon black pepper, or to taste

Basil Oil for garnish (optional)

Shuck the corn and shave the kernels from the cob.  Set the corn kernels aside for later. Snap the cobs in half and place them in a stock pot. Add 12 cups of water. Bring to a vigorous boil, turn down to a low boil, and reduce to 6 cups, about 1 hour. Let cool, discard the cobs, and save the corn stock for the soup.

In a soup pot, warm the olive oil over low heat.  Add onions, carrots, and celery and cook on a low heat until vegetables are soft (this is called sweating). Stir frequently and do not let the vegetables brown.  (To aid the sweating, cover the pan with a lid.)  This will take about 30 minutes, and maybe longer.

Add the corn, garlic, and thyme and cook for 20 minutes, stirring frequently to keep the vegetables from sticking. Keep the heat low and do not allow to brown.

Add corn stock and bring to a simmer/very low boil.  Cook for 30 minutes. The vegetables need to be quite soft. Remove from heat and allow to cool to room temperature.

Add the soup to a blender and puree. Depending on the blender, you might need to do this in batches. Strain through a fine sieve, discarding the solids. The soup is best if velvety-smooth.

Serve hot or chilled, garnished with a drizzle of basil oil. To serve hot, return to the soup pot and heat to a near boil. To serve chilled, refrigerate for at least 4 hours. Can be made several days ahead and refrigerated. The soup will thicken as it sits. If it’s too thick, thin with corn or vegetable stock, and adjust the salt to taste.

Basil Oil: Put 2 tablespoons of minced basil and ½ cup of olive oil into a small blender cup. Blitz until the basil is incorporated. Let sit for one hour and then strain through a small sieve.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

In today’s newsletter podcast, we continue our chat with Dr. Laura Varich, from FreshPhysician.com , a conversation that we began on Episode 228 of the Garden Basics with Farmer Fred podcast. Dr. Varich is a former pediatric radiologist who is now focused on what’s really the cause of so many of the diseases in our society: poor eating habits. Specifically, we are missing a critical element in our diet: phytonutrients. We’re eating too much of colorfully-packaged, highly-processed factory food and not enough fresh from-the-garden (or farmer’s market) colorful food.

The result: rampant increases, across all ages, of heart disease, diabetes, high blood pressure, cancer, and other ailments.

In both podcasts, she encourages getting out into the yard and growing fresh fruits and vegetables, which is also great exercise. The healthiest food you can eat is the food you grow yourself…and then consume it, fresh. Or, at least, make regular runs to the farmer’s market in your area.

What are phytonutrients?

Dr. Varich explains that in the podcasts. And, here’s the word from Harvard University:

Phytonutrients: Paint your plate with the colors of the rainbow

Did you know that adding color to your meals will help you live a longer, healthier life? Colorful fruits and vegetables can paint a beautiful picture of health because they contain phytonutrients, compounds that give plants their rich colors as well as their distinctive tastes and aromas. Phytonutrients also strengthen a plant’s immune system. They protect the plant from threats in their natural environment such as disease and excessive sun.

When humans eat plant foods, phytonutrients protect us from chronic diseases. Phytonutrients have potent anti-cancer and anti-heart disease effects. And epidemiological research suggests that food patterns that include fruits and vegetables are associated with a reduced risk of many chronic diseases, including cardiovascular disease, and may be protective against certain types of cancers.

The American Cancer Society recommends 2 1/2 cups per day of fruits and vegetables. The most recent US Dietary Guidelines recommend consuming even more: 2 1/2 cups of vegetables and 2 cups of fruit, based on a 2,000-calorie diet.

To get started, try to include as many plant-based colors in your meals and snacks as possible. Each color provides various health benefits and no one color is superior to another, which is why a balance of all colors is most important. Getting the most phytonutrients also means eating the colorful skins, the richest sources of the phytonutrients, along with the paler flesh. Try to avoid peeling foods like apples, peaches and eggplant, lest you lose their most concentrated source of beneficial chemicals.

Following is a rundown of fruits and vegetables sorted by color, along with the phytonutrients they contain, and which foods you’ll find them in.

Red: Rich in the carotenoid lycopene, a potent scavenger of gene-damaging free radicals that seems to protect against prostate cancer as well as heart and lung disease.Found in: strawberries, cranberries, raspberries, tomatoes, cherries, apples, beets, watermelon, red grapes, red peppers, red onions.

Orange and yellow: Provide beta cryptothanxin, which supports intracellular communication and may help prevent heart disease.Found in: carrots, sweet potatoes, yellow peppers, oranges, bananas, pineapple, tangerines, mango, pumpkin, apricots, winter squash (butternut, acorn), peaches, cantaloupe, corn

Green: These foods are rich in cancer-blocking chemicals like sulforaphane, isocyanate, and indoles, which inhibit the action of carcinogens (cancer-causing compounds).Found in: spinach, avocados, asparagus, artichokes, broccoli, alfalfa sprouts, kale, cabbage, Brussels sprouts, kiwi fruit, collard greens, green tea, green herbs (mint, rosemary, sage, thyme, and basil)

Blue and purple: Have powerful antioxidants called anthocyanins believed to delay cellular aging and help the heart by blocking the formation of blood clots.Found in: blueberries, blackberries, elderberries, Concord grapes, raisins, eggplant, plums, figs, prunes, lavender, purple cabbage

White and brown: The onion family contains allicin, which has anti-tumor properties. Other foods in this group contain antioxidant flavonoids like quercetin and kaempferol.Found in: onions, cauliflower, garlic, leeks, parsnips, daikon radish, mushrooms

Reach for the rainbow

Reaching a total of 4 1/2 cups of colorful fruits and vegetable a day is the goal for a powerful plate. Here are some ways to make it happen:

* Servings are not that big. 1/2 cup of chopped raw vegetables or fruit makes one serving. Leafy greens take up more space, so 1 cup chopped counts as a serving. 1/2 cup of dried fruit equals one serving.

* Think in twos. Try to eat two servings in the morning, two in the afternoon, and two at night.

* Snacks count, too. Feeling hungry between meals? Munch on a piece of fruit or grab some sliced raw vegetables to go.

* When shopping, look at your cart. If you find most of your choices are the same one or two colors, swap out a few to increase the colors — and phytonutrients — in your cart.

* Dine out colorfully. Start out with a cup of vegetable soup. Choose an arugula or spinach salad and see if they can add extra vegetables. Top off your meal with fresh fruit for dessert and a soothing cup of green tea.

* Look local. Farmers markets, co-ops, buying clubs, and community supported farms are usually great sources of fresh produce. Ask a farmer for fresh ideas on how to prepare fruits and vegetables that are new to you.

* Frozen produce is okay too! It is best to eat in season, but since seasonal produce may be limited, frozen fruits and vegetables count and are just as nutritious as fresh.

In the newsletter podcast, Dr. Varich made an interesting comment, one I had never heard before: in a study published in the British Medical Journal, patients who consumed mainly plants and fish had a 73% chance of not coming down with moderate to severe cases of COVID.

Here’s a brief summary of that 2021 study, conducted by John Hopkins University and other institutions:

Plant-based diets, pescatarian diets and COVID-19 severity: a population-based case–control study in six countries

Abstract

Background: Several studies have hypothesised that dietary habits may play an important role in COVID-19 infection, severity of symptoms, and duration of illness. However, no previous studies have investigated the association between dietary patterns and COVID-19.

Methods: Healthcare workers (HCWs) from six countries (France, Germany, Italy, Spain, UK, USA) with substantial exposure to COVID-19 patients completed a web-based survey from 17 July to 25 September 2020. Participants provided information on demographic characteristics, dietary information, and COVID-19 outcomes. We used multivariable logistic regression models to evaluate the association between self-reported diets and COVID-19 infection, severity, and duration.

Results: There were 568 COVID-19 cases and 2316 controls. Among the 568 cases, 138 individuals had moderate-to-severe COVID-19 severity whereas 430 individuals had very mild to mild COVID-19 severity. After adjusting for important confounders, participants who reported following ‘plant-based diets’ and ‘plant-based diets or pescatarian diets’ had 73% (OR 0.27, 95% CI 0.10 to 0.81) and 59% (OR 0.41, 95% CI 0.17 to 0.99) lower odds of moderate-to-severe COVID-19 severity, respectively, compared with participants who did not follow these diets. Compared with participants who reported following ‘plant-based diets’, those who reported following ‘low carbohydrate, high protein diets’ had greater odds of moderate-to-severe COVID-19 (OR 3.86, 95% CI 1.13 to 13.24). No association was observed between self-reported diets and COVID-19 infection or duration.

Conclusion In six countries, plant-based diets or pescatarian diets were associated with lower odds of moderate-to-severe COVID-19. These dietary patterns may be considered for protection against severe COVID-19.

After the harvest, where do you keep your crops to help preserve their nutrients? Available for free online, from the UC Davis Postharvest Technology department, their “Storing Fresh Fruits and Vegetables for Better Taste” chart.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

Debbie Flower, America’s Favorite Retired College Horticulture Professor, brought up the subject of “Cation Exchange Capacity” back in Episode 193 of the Garden Basics with Farmer Fred podcast, while discussing the limited lifespan of bagged worm castings. That alone should pique your interest. Go ahead and listen to that segment or read the transcript. I’ll wait.

In the podcast in this newsletter, Debbie goes into depth about cation exchange capacity. If you were a high school chemistry class wizard, you’re excited to learn how the electronic charges in the soil aid and abet the feeding of plants. The rest of us need a bit more help (I took high school chemistry a couple of times. I still don’t get it.).

Here’s an almost easy to understand explanation of the chemistry going on beneath our feet. From Australia’s Katharine Brown (The University of Western Australia) and Jeremy Lemon (Department of Agriculture and Food, Western Australia), entitled, “Cations and Cation Exchange Capacity”. At the very least, you’ll learn about “meq”. Again, this is why this newsletter is entitled the way it is.

Cations and Cation Exchange Capacity

Key Points

* Cation exchange capacity (CEC) is the total capacity of a soil to hold exchangeable cations.

* CEC is an inherent soil characteristic and is difficult to alter significantly.

* It influences the soil’s ability to hold onto essential nutrients and provides a buffer against soil acidification.

* Soils with a higher clay fraction tend to have a higher CEC.

* Organic matter has a very high CEC.

* Sandy soils rely heavily on the high CEC of organic matter for the retention of nutrients in the topsoil.

*

Background

Cation exchange capacity (CEC) is a measure of the soil’s ability to hold positively charged ions. It is a very important soil property influencing soil structure stability, nutrient availability, soil pH and the soil’s reaction to fertilisers and other ameliorants (Hazleton and Murphy 2007).

What are exchangeable cations?

The clay mineral and organic matter components of soil have negatively charged sites on their surfaces which adsorb and hold positively charged ions (cations) by electrostatic force. This electrical charge is critical to the supply of nutrients to plants because many nutrients exist as cations (e.g. magnesium, potassium and calcium). In general terms, soils with large quantities of negative charge are more fertile because they retain more cations (McKenzie et al. 2004) however, productive crops and pastures can be grown on low CEC soils.The main ions associated with CEC in soils are the exchangeable cations calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+) (Rayment and Higginson 1992), and are generally referred to as the base cations. In most cases, summing the analysed base cations gives an adequate measure of CEC (‘CEC by bases’). However, as soils become more acidic these cations are replaced by H+, Al3+ and Mn2+, and common methods will produce CEC values much higher than what occurs in the field (McKenzie et al. 2004). This ‘exchange acidity’ needs to be included when summing the base cations and this measurement is referred to as effective CEC (ECEC).

Measuring CEC

Different laboratories use various methods to measure CEC, and can return contrasting results depending on the fraction of the soil measured. In Australia, some laboratories measure CEC directly and others calculate it as CEC by bases. Cation exchange capacity is commonly measured on the fine earth fraction (soil particles less than 2 mm in size). In gravelly soils the effective CEC of the soil as a whole is diluted, and if only the fine (clay) fraction is analysed, reported CEC values will be higher than actual field values.Measuring CEC involves washing the soil to remove excess salts and using an ‘index ion’ to determine the total positive charge in relation to original soil mass. This involves bringing the soil to a predetermined pH before analysis. Methods, including pre-treatment, for measuring CEC and exchangeable cations are presented by Rengasamy and Churchman (1999) and described in detail by Rayment and Higginson (1992).

Units

CEC is conventionally expressed in meq/100 g (Rengasamy and Churchman 1999) which is numerically equal to centimoles of charge per kilogram of exchanger (cmol(+)/kg).

Management Implications

Soil type and CEC

The CEC of soils varies according the clay %, the type of clay, soil pH and amount of organic matter. Pure sand has a very low CEC, less than 2 meq/100 g, and the CEC of the sand and silt size fractions (2 µm/2 mm) of most soils is negligible. Claying sandy soils for managing water repellence increases the CEC of the surface layers by a small amount depending on type and amount of clay added. Typically CEC is increased by less than 1 meq/100 g.The most commonly occurring clay in Western Australian soils, kaolinite, has a CEC of about 10 meq/100 g. Other clays such as illite and smectite have CECs ranging from 25 to 100 meq/100 g. Organic matter has a very high CEC ranging from 250 to 400 meq/100 g (Moore 1998). Because a higher CEC usually indicates more clay and organic matter is present in the soil, high CEC soils generally have greater water holding capacity than low CEC soils.

Soil pH and CEC

Soils dominated by clays with variable surface charge are typically strongly weathered. The fertility of these soils decreases with decreasing pH which can be induced by acidifying nitrogen fertiliser, nitrate leaching and by clearing and agricultural practices (McKenzie et al. 2004). Soil pH change can also be caused by natural processes such as decomposition of organic matter and leaching of cations. The lower the CEC of a soil, the faster the soil pH will decrease with time. Liming soils (see Soil Acidity fact sheet.) to higher than pH 5 (CaCl2) will maintain exchangeable plant nutrient cations.

Nutrient availability and CEC

Soils with a low CEC are more likely to develop deficiencies in potassium (K+), magnesium (Mg2+) and other cations while high CEC soils are less susceptible to leaching of these cations (CUCE 2007). Several factors may restrict the release of nutrients to plants. Some groups promote the controversial idea of managing cation ratios, claiming ideal ratios for Ca:Mg or Ca:K. For plant nutrition, a more critical factor is whether the net amount of Ca or K in the soil is adequate for plant growth. The addition of organic matter will increase the CEC of a soil but requires many years to take effect.Figure 1 illustrates how CEC can change with depth. The sum of the base cations provides an estimate of the CEC of each soil layer. The surface 10 cm has a CEC of 4.6 meq/100 g because of a high organic content. At 10 – 30 cm depth, the organic content of the sand is very low, hence the low CEC. The CEC of the subsoil layers are governed by clay content, 61 %, 51 % and 34 % respectively. The dominant clay in this soil is kaolinite so CEC values remain low.

Figure 1: Sandy duplex soil, with clay at 40 cm. Note the high CEC of the clay below 40 cm, and the impact of organic matter on the sand’s CEC.

Further reading and references

Cornell University Cooperative Extension (CUCE) (2007) Cation Exchange Capacity (CEC). Agronomy Fact Sheet Series # 22. Department of Crop and Soil Sciences, College of Agriculture and Life Sciences, Cornell University.

Hazelton PA, Murphy BW (2007) Interpreting Soil Test Results: What Do All The Numbers Mean?. CSIRO Publishing: Melbourne.

McKenzie NJ, Jacquier DJ, Isbell RF, Brown KL (2004) Australian Soils and Landscapes: An Illustrated Compendium. CSIRO Publishing: Collingwood, Victoria.

Moore G, Dolling P, Porter B and Leonard L (1998) Soil Acidity. In Soilguide. A handbook for understanding and managing agricultural soils. (Ed. G Moore) Agriculture Western Australia Bulletin No. 4343.

Rayment GE, Higginson FR (1992) Electrical Conductivity. In ‘Australian Laboratory Handbook of Soil and Water ChemicalMethods’ Inkata Press: Melbourne.

Rengasamy P, Churchman GJ (1999) Cation Exchange Capacity, Exchangeable Cations and Sodicity. In Soil Analysis anInterpretation Manual. (Eds KI Peverill, LA Sparrow and DJ Reuter). CSIRO: Melbourne.

Author: Katharine Brown (The University of Western Australia) and Jeremy Lemon (Department of Agriculture and Food, Western Australia).

This soilquality.org.au fact-sheet has been funded by the Healthy Soils for Sustainable Farms programme, an initiative of the Australian Government’s Natural Heritage Trust in partnership with the GRDC, and the WA NRM regions of Avon Catchment Council and South Coast NRM, through National Action Plan for Salinity and Water Quality and National Landcare Programme investments of the WA and Australian Governments.The Chief Executive Officer of the Department of Agriculture and Food, The State of Western Australia and The University of Western Australiaaccept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

In today’s newsletter podcast, America’s Favorite Retired Horticultural Professor, Debbie Flower, explains plant hormones, and how they can help you become a better gardener.

Want to propagate your own plants from cuttings? Depending on the plant, hormones can help.

The book, “Propagating Plants” by Alan Toogood has more information. Online, the site “Untamed Science” has an easy to understand page on how the five major plant hormones work.

Want bigger table grapes?

Hormones, such as Gibberellic acid can help. If you’re a commercial grower. According to the California Garden Web:

“Growers use several methods to increase cluster and berry size: cluster and berry thinning; trunk girdling; and gibberellic acid sprays. Gibberellic acid is a synthetic plant growth regulator and is not available to home gardeners. Some increase in size can be achieved by cluster and berry thinning and trunk girdling.”

How To Increase The Size Of Your Seedless Table Grapes

Mid-Spring is the best time to thin out, trim and fertilize seedless table grapes.

1. Thin out the bunches so that there is at least six inches of space between each remaining bunch ot table grapes. 

Late April to mid May is best for this.

 2. Cut off the "tails" from the remaining bunches at that same time. This is the lower one-quarter to one third of the bunch, where it begins to taper down in size. This will send more energy to the remaining grapes on the bunch.

 3. Fertilize...or not. The book, "The California Master Gardener Handbook" advises that a half pound of ammonium sulfate can be applied for each vine at berry set (when the berries are about a quarter-inch big, usually in May). Remember, though, that too much nitrogen can result in an overabundance of vine growth and not enough grapes for eating. The late Chuck Ingels, Sacramento County farm advisor, said that very little nitrogen, if any, is needed. If you opt to use another commercial fertilizer, follow label directions. 4. Water. The same book advises gardeners to apply about 50 gallons of water per week per vine, during the hottest months (June through August) in the Central Valley of California. Apply less (about 35 gallons a week) during May and September. 5. Girdle the Stems in late May. According to Chuck Ingels, in the Sacramento County Cooperative Extension brochure, "Grapevines: Girdling and Cluster Thinning to Increase Berry Size":

Girdling removes the inner and outer bark from around the trunk. The inner bark, or phloem, is where carbohydrates produced by photosynthesizing leaves move to developing organs (including fruit and roots). Removal of a strip of bark prevents the translocation of carbohydrates to the root system thus making more available for fruit growth until the girdle heals in about four weeks. Girdling can make berries about 30% larger if done correctly. If is particularly effective on seedless varieties; no effect on seeded varieties.How to Girdle Vines: Remove a strip of bark, down to the wood, that is 1/8 to 1/4 inch wide. A double bladed girdling knife makes the job easier. It is essential that all the phloem tissue is removed, so press fairly hard. Check for completeness about 20 minutes afeter the girdle is made. A proper girdle will have the appearance of an all white, fibrous ring of wood (xylem). Remove any brown portions of the ring; if there is even an 1/8" of phloem tissue left, the girdle's benefits are lost. Be sure not to cut so deep as to damage the water conducting xylem and weaken the vine. With a proper cut, the ring should just pop out."

For commercial growers: “Using Plant Growth Regulators to Increase the Size of Table Grape Berries”

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

A question into the Garden Basics with Farmer Fred podcast raised more questions for myself and Debbie Flower, America’s Favorite Retired College Horticulture professor. First, the question:

“Recently, a Pest Control Company came by to inject my birch trees (soil) with a chemical (Imidacloprid) that helps prevent sticky droppings from landing on my driveway, etc.

This year they came by and also started inject all  shrubs and also injected my plum tree and lime tree.  I asked why and they said it was part of their new procedure.  I am concerned that my limes and plums may not be safe to eat.  Is this a worry?  While I only make jam out of the plums, I do enjoy fresh lime juice.

Thanks.”

You’ll have to listen to the podcast (above) where we enumerate the many ramifications raised by this question, such as: What was the exact concentration of Imidacloprid used? Is the product registered for use on the crop of concern? Is the pest listed on the product label? All of this information could be found on the product label. Which is why we are fond of saying: read and follow all label directions.

Imidacloprid is an active ingredient in many popular systemic insecticides. It’s also banned in some regions. Scientists have pointed out that the government (the EPA) needs to take a harder look at this insecticide due to its effect on pollinating insects, such as honeybees. From the October 31, 2021 International Journal of Molecular Sciences:

“In conclusion, the lethal dose/concentration and molecular effects of sublethal dosages of imidacloprid on honey bees and other pollinator bees were integrated and reviewed. Molecular evidence suggests that the expression of the immune response, detoxification, oxidation-reduction, and other development-related genes was ubiquitously affected among different species of target bees. Transcriptomic approaches revealed that even very low dosages/concentrations of imidacloprid could cause global effects, even altering the developmental queue and inducing a precocious forager. Realistic field levels of imidacloprid severely impact the sustainable development and population dynamics of domesticated and wild pollinators. The application of imidacloprid and other neonicotinoid pesticides should be more carefully and rigorously evaluated.”

What is Imidacloprid?

From the National Pesticide Information Center at Oregon State University:

What is imidacloprid?

Imidacloprid is an insecticide that was made to mimic nicotine. Nicotine is naturally found in many plants, including tobacco, and is toxic to insects. Imidacloprid is used to control sucking insects, termites, some soil insects, and fleas on pets. It has been used in products sold in the United States since 1994.

What are some products that contain imidacloprid?

Products containing imidacloprid come in many forms, including liquids, granules, dusts, and packages that dissolve in water. Imidacloprid products may be used on crops, houses, or used in flea products for pets. There are over 400 products for sale in the United States that contain imidacloprid.

Always follow label instructions and take steps to avoid exposure. If any exposures occur, be sure to follow the First Aid instructions on the product label carefully. For additional treatment advice, contact the Poison Control Center at 1-800-222-1222. If you wish to discuss a pesticide problem, please call 1-800-858-7378.

How does imidacloprid work?

Imidacloprid disrupts the nerve's ability to send a normal signal, and the nervous system stops working the way it should. Imidacloprid is much more toxic to insects and other invertebrates than it is to mammals and birds because it binds better to the receptors of insect nerve cells.

Imidacloprid is a systemic insecticide, which means that plants take it up from the soil or through the leaves and it spreads throughout the plant's stems, leaves, fruit, and flowers. Insects that chew or suck on the treated plants end up eating the imidacloprid as well. Once the insects eat the imidacloprid, it damages their nervous system and they eventually die.

How might I be exposed to imidacloprid?

There are four ways that people can be exposed to chemicals. Chemicals may get on the skin, get into the eyes, be inhaled, or be eaten. This can happen if someone handles a pesticide or a pet recently treated with a product and does not wash their hands before eating. You could be exposed to imidacloprid if you are applying a product to your yard, on a pet, or in another location and get the product on your skin or breathe in spray mist. Because imidacloprid is a systemic insecticide, you could be exposed to imidacloprid if you ate the fruit, leaves, or roots of plants that were grown in soil treated with imidacloprid.

From the submitted product label of a supplier of imidacloprid to the EPA, intended for use by homeowners, comes this series of warnings:

The questioner in the podcast was wondering how safe is it to eat the fruit or drink the juice of a lime from his backyard tree. The answer, again: it depends. It depends on the concentration of the Imidacloprid in the product, as well as the harvest date, if any. From an Imidacloprid-containing product label aimed at the home market, here some information in that regard.

Note that the label for citrus contains no “Do Not Harvest Fruit Until…” warning.

The bottom line: for pest control, identify the pest. Start with the least toxic remedies. Pesticides should be the last resort, if necessary. When using pesticides, READ AND FOLLOW ALL LABEL DIRECTIONS. If employing a pest control company, ask to see the label of the product they are applying. Chances are, they are using a formulation that is more concentrated than what you would find at a garden center. Different concentrations may have different application regulations.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

It happens without warning every summer. A tree branch from an oak, eucalyptus, elm, ash, or other large, old tree crashes to the ground on a warm, non-windy day. It’s a phenomenon referred to as sudden limb failure or summer branch drop. According to the Butte County (CA) Master Gardeners newsletter:

“A break due to summer branch drop usually occurs three to twelve feet away from the trunk, along the length of the branch. The broken branches are usually long and horizontal, as opposed to upright, frequently extending to or beyond the average tree canopy. While some limbs that drop show evidence of wounds or decay, many of these failed limbs appear to be quite sound. Older, less vigorous trees seem to be more prone to this problem. Once a tree has lost a limb due to summer branch drop, it is more likely to lose another.”

Why sudden limb failure happens is not very well understood. The Butte County Master Gardeners newsletter goes on to discuss the possibility of the combination of drought and ethylene gas, a hormone found in all plants, as being part of the problem:

“Drought stress during a hot, calm afternoon reduces the flow of water in the branch, causing the branch temperature and the concentration of ethylene to increase. Ethylene is known to promote the process of cell aging. Elevated levels of ethylene may weaken the cell wall cementation, which when coupled with reduced transpiration and increased root pressure, increases internal sap pressure, moisture content of branches, and limb weight, resulting in branch failure. Old wounds and decay hidden inside a limb, possibly resulting from improper pruning, occasionally contribute to branch drop, but this does not account for the majority of summer branch drop failures. Pruning that encourages uneven growth at the end of a limb can put tremendous stress on the limb due to the added weight of the new growth.

Although there is no guaranteed way to prevent summer branch drop, several things can be done to mitigate this hazard in oaks and other commonly affected tree species such as eucalyptus, elm, and ash.  On mature trees, shorten and lighten long horizontal branches and open up the tree by thinning to healthy lateral branches to reduce branch weight.  Inspect the tree for externally visible defects and prune out damaged or sickly low-vigor limbs that have decay or cavities.  Although watering is required to keep most ornamental trees healthy in hot summer climates, don't forget that summer moisture can encourage oak root fungus and other oak pathogens that can kill oaks when the summer-watered area is within 10 feet of the trunk.  Finally, do not park cars or place play structures, benches, or picnic tables beneath older, susceptible trees.  Falling limbs can't harm people - or property - if they aren't under the tree.”

If you own any large, old trees, it pays to hire an arborist to come out and examine your trees. Regular tree inspections every few years can spot trouble before it happens, especially weakly attached branches, injuries, or disease.

Many times, though, homeowners choose an arborist without doing their due diligence. Make sure whomever you hire is licensed, bonded, and insured. Under some circumstances you might be held financially responsible if an uninsured worker is hurt on your property, or damage is done to a neighbor’s property. Have more than one arborist submit an estimate.

Also, consider hiring a specialist, a consulting arborist. Their job is to tell you what’s wrong with your trees, in writing. 

“I think a consulting arborist can provide the best value actually, in many cases for a homeowner, when they actually call us before they need us,” Bay Area-based consulting arborist Michael Santos told us in today’s newsletter podcast. “They think their tree is fine. Or maybe they've just acquired the property and these trees are new to them, they have no history with them, and they want to know what they need to do. Oftentimes, a consulting arborist can provide the best value before something negatively has happened to the tree like a large limb failure, or a significant disease has started. Calling us sooner rather than later can really help the longevity and the outcome for their trees.”

One professional organization that can help you find an arborist or consulting arborist is the International Society of Arboriculture (ISA), online at Treesaregood.org. At the ISA website, you may enter your zip code or city and obtain a list of certified arborists in your area. In the meantime, watch where you park your car in the summertime.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe

“Of all flowers, methinks rose is best”. Shakespeare said that. He lived in Stratford-upon-Avon, about halfway between London and Birmingham, England. However, the roses he saw 600 years ago never endured 100 degree heat…until recently.

Although roses were found originally in Central Asia, they spread quickly throughout the Northern Hemisphere between the 12th and 18th centuries.

Those old roses wouldn’t stand a chance in the heatwaves of the 21st century, succumbing to scorched flowers, leaves, and buds…as well as dying off due to a lack of regular watering in drought-effected areas.

Of course, hybridization of roses in the 19th, 20th and 21st centuries has created varieties that can withstand a number of modern ailments, including air pollution.

So, what are the modern roses that can take the heat, when temperatures hit 100 degrees for several days in a row? What are the traits of a heat-tolerant rose?

Master Rosarian Debbie Arrington of the Sacramento Rose Society (and the Sacramento Digs Gardening blog) enumerated several in the podcast at the top of this page. Sacramento (City Motto: “At Least It’s a Dry Heat”) is no stranger to prolonged, triple digit heat waves, which can occur anytime from May through September. So, the area is a good testing ground for roses that maintain their color, health and vigor throughout spring, summer - and sometimes fall - heatwaves. One trait many of these have in common: these rose bushes produce light-colored blooms of white, pink or yellow. Most red roses, Arrington explains, absorb more of the heat, and will be among the first to scorch. Sorry about that, Bobby Darin.

Among the roses on Debbie Arrington’s list of heat-tolerant roses:

Iceberg

Iceberg is a floribunda rose, a class of roses characterized, according to the American Rose Society’s Handbook for Selecting Roses, by its “profuse ability to bear flowers in large clusters or trusses with more than one bloom in flower at any one time. This class is unrivaled for providing massive, colorful, long-lasting garden displays… Floribundas are hardier, easier to care for and more reliable in wet weather than their hybrid tea counterparts.” Iceberg was introduced in 1958.

Julia Child

Master Rosarian Charlotte Owendyk of the Sierra Foothills Rose Society loves Julia Child so much, it lines her walkway. A floribunda with medium yellow blooms, this 2005 introduction - one that is also on Debbie Arrington’s list of heat tolerant roses - is also an American Rose Society’s Members’ Choice winner and an All-America Rose Selections champion.

Joy

One of my favorite miniature roses that blooms it’s little head off, despite being grown in a container, sitting on reflective rocks, facing south, with the hottest side of the house right behind it. Debbie Arrington likes it, too. A pink blend, Joy was introduced in 2007. Joy was an American Rose Society Award of Excellence Winner, as well as an ARS Members’ Choice winner.

Here are a few other roses that are heat-tolerant, according to Debbie Arrington. Listen to her descriptions of these roses in the podcast at the top of the page.

Shockwave (Floribunda)

Day Breaker (Floribunda)

First Prize (Hybrid Tea)

Baldo Villegas and his namesake rose (mini-floribunda)

And, I’m out of room for more pictures. The rest of the heat tolerant roses that Debbie mentions in the podcast:

Edisto (miniature)

Whirlaway (mini-floribunda)

Innocence (miniature)

The Drift Series of low growing shrub roses

The Knock Out collection of landscape roses, especially Home Run.

Thank you for listening to the Garden Basics with Farmer Fred podcast! It’s available wherever you get your podcasts. Please share it with your garden friends.

As an Amazon Associate, I earn from qualifying purchases from some of the underlined links in the newsletter. This is how I am trying to keep this a free newsletter. And as long as you buy whatever you want from Amazon using any of those links to get into the Amazon site, I get a few pennies. Thank you.

Thanks for Subscribing and Spreading the Word About the Beyond the Basics: The Garden Basics with Farmer Fred newsletter, I appreciate your support. 

Fred Hoffman is also a University of California Cooperative Extension Master Gardener in Sacramento County.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit gardenbasics.substack.com/subscribe