Vineyard Underground

In this episode of Vineyard Underground, Fritz talks with Dr. Mark Krasnow of Thoughtful Viticulture about how to tell real vine stress from false alarms in the vineyard.

Mark explains why grapevines are often tougher than they look and breaks stress into three main categories: water, heat, and wind. He and Fritz highlight common misreads and show how these assumptions lead to overwatering, shallow roots, excess vigor, and higher disease risk.

The conversation focuses on using data instead of guesswork, pairing tools such as pressure bombs, porometers, and soil moisture probes so growers can set meaningful irrigation thresholds. Mark also shares why he prefers early-season water stress for red varieties to influence berry size and phenolics, while keeping vines better supplied after veraison.

They compare stress responses in young versus mature vines and touch on Mark's work with powdery mildew spore monitoring, which suggests many early-season sprays may be unnecessary.

In this episode, you will hear:

• Why grapevines are often more resilient than growers assume

• How overwatering can create shallow roots, excess vigor, and more disease risk

• The difference between perceived water stress and measured stress

• How to pair soil moisture probes with pressure bomb readings to set a real "red line" for irrigation

• Why early-season water stress can improve red wine quality when managed correctly

• How vine age affects stress tolerance and root development

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

If you're starting a vineyard or thinking about starting a vineyard, visit https://www.virtualviticultureacademy.com/growsmart to get Fritz's online Prospective Winegrape Grower Course to help you get your vineyard planned and planted correctly from the start. Use the code PODCAST at checkout to save $89.99 as a thank you for being a podcast listener.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Today's Guest:

Dr. Mark Krasnow is a renowned plant physiologist and consultant and the founder of Thoughtful Viticulture – a company that helps vineyards grow the highest quality fruit in the most sustainable and efficient manner possible.

Connect with Mark at thoughtfulviticulture.com and follow him @drkraz or on his blog https://www.thoughtfulviticulture.com/blog.

Episode Sponsor:

Today's episode was brought to you by HydroGeo Environmental and SensorInsight.

Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.

Thank you to SensorInsight for sponsoring today's episode. SensorInsight is a leader in vineyard soil moisture and weather monitoring. SensorInsight designs state-of-the-art, remote satellite monitoring of soil moisture and weather, bringing actionable information for your vineyard operations straight to your phone, with real-time data so you can best decide when to turn on your irrigation, how long to run the system, and learn how the dynamics of soil moisture can change over a given season. Visit them today at https://sensorinsight.io. And don't forget to mention the code Underground to receive a discount on your SensorInsight solution.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

In this conversation, Fritz continues his deep dive with Thijs Verschuuren of Herman J. Wiemer, exploring practical baby steps toward biodynamic and organic vineyard management. Thijs walks through how he structures a non-systemic spray program in a high-disease-pressure region, breaking down critical spray timing, coverage strategies, and why he treats bloom and cap fall as "non-negotiable" spray windows.

They discuss how Thijs combines copper, sulfur, plant teas, biologicals, and newer tools like chitosan-based fungicides and kaolin clay to target downy mildew, black rot, powdery mildew, and leafhoppers, while staying within strict copper limits and managing livestock safety.

Fritz and Thijs also cover biodynamic teas, how forecasting and 48‑hour brews fit into a preventive program, and why daily scouting and mapping disease "pockets" are essential. The conversation concludes with canopy management, pruning, mechanization, and thoughtful leaf removal that maintain disease control without sacrificing the acidity and fruit quality of Riesling and Chardonnay on the path to Demeter certification.

In this episode, you will hear:

• Why spray timing and coverage matter more than product choice in organic and biodynamic programs

• How to integrate copper, sulfur, oils, chitosan, and kaolin clay while respecting label limits and site conditions

• Practical strategies for managing downy mildew, black rot, and powdery mildew with a mostly protectant toolbox

• How biodynamic teas and preparations fit into a preventive, weather‑driven vineyard health program

• Daily scouting, mapping, and localized spraying as core tools to limit disease spread and input use

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Today's Guest:

Thijs Verschuuren is the Director of Vineyard Biology & Biodynamic Specialist at Hermann J. Wiemer Vineyard in upstate New York.

Connect with Thijs at https://www.wiemer.com/ or follow him at hermannjwiemer.

Resources:

Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Episode Sponsor:

Today's episode was brought to you by Clemens and HydroGeo Environmental.

Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at [email protected] with any questions.

Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

In this episode, we dig into what it really looks like to take manageable, real-world steps toward biodynamic and organic winegrowing with Thijs (Taze) Verschuuren, Director of Vineyard Biology and biodynamic specialist at Hermann J. Wiemer Vineyard in New York's Finger Lakes.

We follow Thijs's path from European wine regions to the Finger Lakes and unpack the make-or-break 2018 season. That side‑by‑side contrast pushed the team to fully embrace biodynamics and pursue Demeter certification.

We break down biodynamics in practical terms: treating the farm as a living, self-sustaining organism that integrates cover crops, livestock, compost, and on-farm preparations to build resilience from the soil up. Then we zoom into vineyard floor management as an accessible entry point, showing how diverse clover mixes, smarter mowing vs. crimping decisions, and minimal cultivation helped boost soil organic matter from ~1.7% to over 6% in about seven years — one "baby step" at a time.

In this episode, you will hear:

• Why a wet 2018 season pushed Hermann J. Wiemer to deepen its biodynamic commitment

• How biodynamics differs from organics in philosophy and farm design

• A practical framework for cover crops (especially clovers) to build organic matter and vine resilience

• When to mow, when to crimp, and why there's no "set-it-and-forget-it" spray or floor program

• Baby-step starting points: soil testing, cover cropping, and small-scale animal integration

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Today's Guest:

Thijs Verschuuren is the Director of Vineyard Biology & Biodynamic Specialist at Hermann J. Wiemer Vineyard in upstate New York.

Connect with Thijs at https://www.wiemer.com/ or follow him at hermannjwiemer.

Resources:

Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Episode Sponsor:

Today's episode was brought to you by Clemens and HydroGeo Environmental.

Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at [email protected] with any questions.

Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

We mark a major milestone with our 100th episode by stepping back to look at where the vineyard industry has been and where it's headed next. Fritz walks us through what's in, what's out, and what's coming for growers who want to stay profitable and resilient.

We start with the changing economics of grape growing. Planting Cab, Merlot, or Syrah on speculation no longer pencils out in an oversupplied market. Instead, we focus on matching varieties to region, climate (including future climate), water availability, disease pressure, and a clearly defined sales channel.

From there, we connect vineyard design to labor and equipment realities. We move away from high‑input, labor‑intensive layouts and toward simpler, mechanization‑friendly systems that can eventually support autonomous tools.

We then turn to the vineyard floor, moving from bare soil and blanket herbicide programs to living systems built around cover crops, reduced tillage, and grazing with sheep. By the end, we have a clear picture of the practices that are fading, the ones gaining momentum, and the directions we can embrace to stay ahead in the next decade of grape growing.

We look forward to the next 100 episodes!

In this episode, you will hear:

• Planting on speculation is out; committed buyers and clear sales channels are in

• Variety selection must fit climate, water, disease pressure, and market identity

• High-input, labor-intensive designs are giving way to mechanization‑friendly trellis systems and layouts

• Soil and irrigation should be managed as one integrated system

• Living vineyard floors are key to long‑term soil health

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Episode Sponsor:

Today's episode was brought to you by Vigneron Toy Store and HydroGeo Environmental.

Thank you to Vigneron Toy Store for sponsoring today's episode. Vigneron Toy Store specializes in Harvesters, Sprayers, Frost Mitigation Equipment, Canopy Management Trimmers, and more. As grape growers themselves, they can expertly help you determine the best equipment for your specific vineyard needs. And, as a special offer for our podcast listeners, you can save 5% on in-stock machines by entering the promo code Underground on the contact form at vignerontoystore.com.

Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

Dr. Katie Gold and Dave Combs from Cornell University join Fritz to unpack one of the most confusing topics facing winegrape growers today: how biological fungicides truly fit into a spray program.

Katie explains how the Cornell grape pathology program has expanded rapidly, moving from strictly conventional efficacy trials into extensive work with biologicals as more of these products come out of R&D pipelines. She outlines why growers can't rely on "the next new conventional" anymore and how biologicals are becoming essential tools for sustainable disease management and resistance stewardship.

Dave brings decades of field experience and shares how his initial skepticism about biologicals shifted after seeing modern products perform on highly disease‑prone varieties in one of the toughest vineyards for powdery mildew, downy mildew, black rot, and bunch rots. Together, they walk through what "compatibility" really means and why water pH, formulation, and whether an organism is alive or dead matter far more than many growers realize.

Listeners learn why mixing biologicals and conventionals in the same tank often provides no added control (and may waste money), where negative interactions can show up, and why tightening intervals and understanding infection periods is critical when working with protectant biologicals.

In this episode, you will hear:

• Why more new products in the pipeline are biologicals rather than conventional chemistries
• How Cornell's high‑pressure pathology vineyard reveals the real-world limits and strengths of biologicals
• Why many biologicals are strictly protectants and must be applied before significant disease is present
• How tank mixing biologicals with conventionals can reduce cost-effectiveness without improving control
• Why understanding water chemistry, pH, and product formulation is now an essential spray-program strategy

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Today's Guest:

Dr. Katie Gold is an Assistant Professor of Grape Pathology at Cornell University, where she holds primary research and extension responsibilities for grape disease management in New York State.

Dave Combs is a Research & Extension Support Specialist II in Dr. Katie Gold's Grape Pathology Laboratory at Cornell AgriTech in Geneva, New York, with 20+ years of experience in chemical and cultural grape disease management.

Connect with Katie: https://cals.cornell.edu/kaitlin-gold

Visit the Gold Lab to view their research work: https://blogs.cornell.edu/goldlab/

Episode Sponsor:

Today's episode was brought to you by Shellt Grow Tubes and Vigneron Toy Store

Thank you to Shellt Grow Tubes for sponsoring today's episode. Shellt makes the ultimate grow tubes for grape vines and orchard trees. Their grow tubes are reusable, recyclable, and designed to grow with your vineyard by clicking together for taller or wider coverage. I exclusively recommend Shellt Grow Tubes to the growers I work with. Visit https://www.shellt.us/ and order with the code UNDERGROUND to save 15% off all online orders, plus free shipping within the continental United States.

Thank you to Vigneron Toy Store for sponsoring today's episode. Vigneron Toy Store specializes in Harvesters, Sprayers, Frost Mitigation Equipment, Canopy Management Trimmers, and more. As grape growers themselves, they can expertly help you determine the best equipment for your specific vineyard needs. And, as a special offer for our podcast listeners, you can save 5% off in-stock machines by entering the promo code Underground on the contact form at vignerontoystore.com.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

Small vineyard decisions made early in the season can create major ripple effects later in the year, and in this episode, Fritz breaks down three vineyard management tasks that are frequently skipped, delayed, or underestimated despite their outsized impact on vine health, fruit quality, and long-term vineyard performance.

Fritz focuses first on shoot thinning and explains why timing is everything. He walks through the economic and practical advantages of thinning early, including improved spray penetration, better airflow, easier hand harvesting, and even reduced pruning labor during dormancy.

He then explains why bloom and veraison sampling windows are critical for understanding nutrient status and preventing deficiencies before they become costly problems. Lastly, he tackles water stress monitoring and the common misconceptions surrounding vineyard stress.

Listen in for practical ways growers can monitor irrigation effectiveness, evaluate soil moisture, and avoid relying solely on visual assumptions about vine stress levels. Remember, better data leads to better vineyard decisions.

In this episode, you will hear:

• Early shoot thinning can improve fruit quality, airflow, spray coverage, and long-term pruning efficiency

• Delayed shoot thinning increases labor costs and creates more winter pruning wounds susceptible to trunk disease

• Tissue sampling at bloom and veraison helps growers identify nutrient deficiencies before productivity suffers

• Leaf blade sampling may provide more reliable nutrient data than petiole sampling for many nutrients

• Water stress should be monitored with both field observation and measurable soil moisture data

• Excess vigor, nutrient imbalance, weather extremes, fungal disease, and insects can all contribute to flower browning during bloom

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

Get Fritz's Shoot Thinning, Tissue Sampling, and Plant Stress resources available for podcast listeners at VirtualViticulureAcademy.com/tasks.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Episode Sponsor:

Today's episode was brought to you by SensorInsight and Clemens Technologies.

Thank you to SensorInsight for sponsoring today's episode. SensorInsight is a leader in vineyard soil moisture and weather monitoring. SensorInsight designs state-of-the-art, remote satellite monitoring of soil moisture and weather, bringing actionable information for your vineyard operations straight to your phone, with real-time data so you can best decide when to turn on your irrigation, how long to run the system, and learn how the dynamics of soil moisture can change over a given season. Visit them today at https://sensorinsight.io. And don't forget to mention the code Underground to receive a discount on your SensorInsight solution.

Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at [email protected] with any questions.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

We are back with another solo episode! Fritz dives into the world of Reddit viticulture advice to separate helpful guidance from misleading recommendations. Using real vineyard and winemaking questions pulled from Reddit threads, Fritz evaluates the quality of the responses while adding his own professional perspective.

The episode covers a wide range of vineyard topics, but throughout it, Fritz highlights an important lesson for growers at every level: context matters. Many online answers contain kernels of truth, but successful vineyard management depends on site conditions, climate, soil, vine age, regional disease pressure, and long-term goals. He explains why broad internet advice often lacks the specificity growers actually need to make confident decisions.

Listeners will come away with a fresh perspective on vineyard establishment, irrigation management, pruning strategies, disease prevention, and realistic expectations for small-scale winegrowing projects.

In this episode, you will hear:

• Establishing vineyards in cool climates like the UK and Northern Europe

• PIWI grape varieties and disease-resistant planting strategies

• Realistic timelines for vineyard establishment and first harvests

• Challenges of starting and managing a small hobby vineyard

• Irrigation management for young vines during extreme summer heat

• Reviving neglected Frontenac and Edelweiss vineyards in the Midwest

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

If you're starting a vineyard or thinking about starting a vineyard, visit https://www.virtualviticultureacademy.com/growsmart to get Fritz's online Prospective Winegrape Grower Course to help you get your vineyard planned and planted correctly from the start. Use the code PODCAST at checkout to save $89.99 as a thank you for being a podcast listener.

Get more information from Fritz about soil moisture sensors – types of sensors, location and placement, installation, and understanding soil monitoring data at https://www.virtualviticultureacademy.com/sensor.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Episode Sponsor:

Today's episode was brought to you by Vintner's Vault and Vigneron Toy Store.

Thank you to Vintner's Vault for sponsoring today's episode! Vintner's Vault is the #1 winery equipment company that I recommend to my growers, who are also winemakers. Visit TheVintnerVault.com and use the code UNDERGROUND5 (all caps) to save 5% off of your online order, or mention that you heard about them on the Vineyard Underground podcast when contacting them for a larger piece of equipment, consulting services, or turn-key packages, and they will provide a podcast listener discount for you.

Thank you to Vigneron Toy Store for sponsoring today's episode. Vigneron Toy Store specializes in Harvesters, Sprayers, Frost Mitigation Equipment, Canopy Management Trimmers, and more. As grape growers themselves, they can expertly help you determine the best equipment for your specific vineyard needs. And, as a special offer for our podcast listeners, you can save 5% off in-stock machines by entering the promo code Underground on the contact form at vignerontoystore.com.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

Plant growth regulators (PGRs) are powerful tools that can dramatically influence vine performance, but they also come with complexity and risk. In this episode, Fritz welcomes back Dr. Matthew W. Fidelibus of UC Davis to explore how these compounds are used across table, raisin, and wine grape production.

Dr. Fidelibus explains that PGRs include both naturally occurring plant hormones and synthetic compounds that mimic hormonal effects. While they've long been foundational in table grape production, their use in winegrapes is far less common and more nuanced. The conversation highlights how sensitivity to timing, rate, and variety is critical, with even small misapplications potentially affecting fruit set, bud development, or yields across multiple seasons.

Fritz and Dr. Fidelibus dig into specific compounds like gibberellic acid, abscisic acid, and ethephon, discussing how they can influence berry size, cluster architecture, color development, and ripening. They also explore emerging research on improving color in virus-affected vineyards, delaying ripening in warm climates, and even modifying aroma profiles.

A key takeaway is that PGRs are not a one-size-fits-all solution. They require careful evaluation, regulatory compliance, and, ideally, small-scale trials before broader use. For growers facing challenges like poor fruit set, uneven ripening, or compact clusters, these tools may offer targeted solutions — but only when used with precision and a strong understanding of vine physiology.

Listeners will walk away with a clearer understanding of both the potential and the pitfalls of incorporating PGRs into vineyard management.

In this episode, you will hear:

• Overview of plant growth regulators and how they influence vine physiology

• Historical use of PGRs in table and raisin grape production

• Key compounds like gibberellic acid, abscisic acid, and ethephon

• Applications for cluster thinning, berry sizing, and color development

• Challenges and risks of using PGRs in winegrapes

• Emerging research, including virus mitigation and ripening control

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

Come grow with Fritz through https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Today's Guest:

Dr. Matthew W. Fidelibus is an extension specialist in the Department of Viticulture and Enology, UC Davis.

Connect with Matthew and view his research – https://wineserver.ucdavis.edu/people/matthew-fidelibus#/ or follow him at https://bsky.app/profile/viticulture.bsky.social

Episode Sponsor:

Today's episode was brought to you by Clemens Technologies and SensorInsight.

Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at [email protected] with any questions.

Thank you to SensorInsight for sponsoring today's episode. SensorInsight is a leader in vineyard soil moisture and weather monitoring. SensorInsight designs state-of-the-art, remote satellite monitoring of soil moisture and weather, bringing actionable information for your vineyard operations straight to your phone, with real-time data so you can best decide when to turn on your irrigation, how long to run the system, and learn how the dynamics of soil moisture can change over a given season. Visit them today at https://sensorinsight.io. And don't forget to mention the code Underground to receive a discount on your SensorInsight solution.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

Organic grape production is gaining momentum, but making the transition from conventional farming requires careful planning, patience, and a willingness to adapt. In this episode of Vineyard Underground, Fritz welcomes Rob Warren, owner and operator of Desert Willow Vineyard and Warren Farms in Seminole, Texas, to share his experience converting his vineyard to certified organic production.

Rob explains how his agricultural background in organic row crops gave him experience with organic systems long before he applied those principles to grape growing. As consumer demand began to shift toward more natural and sustainably produced wines, wineries started seeking organic fruit, prompting Rob to pursue certification.

During the conversation, Fritz and Rob walk through the realities of transitioning a vineyard to organic management. Rob discusses the three-year certification timeline, the importance of documenting the final use of conventional inputs, and the need for growers to rethink pest, disease, and weed management strategies.

A major focus of the episode is that Rob uses sheep in the vineyard. The sheep help control weeds, provide natural fertilization, and even assist with canopy management by removing leaves in the fruiting zone.

Throughout the episode, Rob provides honest background information on the challenges and the long-term benefits of improved soil health and stronger vine resilience.

For vineyard owners considering organic production, this episode offers practical guidance and real-world lessons from a grower who has successfully made the switch.

In this episode, you will hear:

• Market demand from wineries and consumers increasingly favors organic grape production

• Weed management is often the biggest early challenge when moving away from conventional herbicides

• Sheep can play a valuable role in weed control, fertilization, and canopy leaf removal

• Organic pest and disease control often requires more frequent monitoring and spray applications

• Soil health improvements through cover crops and livestock integration strengthen long-term vineyard resilience

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

Register for Fritz's live, virtual two‑day Early Season Vineyard Management Bootcamp on April 22nd and 23rd.

Come grow with Fritz through https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Today's Guest:

Rob Warren is the owner and operator of Desert Willow Vineyard and Warren Farms in Seminole, Texas, and a leading innovator in regenerative and organic vineyard management and farming.

Connect with Rob:

• Facebook: https://www.facebook.com/desertwillowvineyard

• Instagram: https://www.instagram.com/desertwillowvineyard/

• YouTube: https://www.youtube.com/channel/UCrjWaulJw7tATQC3trzhPJQ

Episode Sponsor:

Today's episode was brought to you by Clemens Technologies and Sunridge Nurseries.

Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at [email protected] with any questions.

Thank you to Sunridge Nurseries for sponsoring today's episode. Sunridge Nurseries is the exclusive nursery sponsor of the Vineyard Underground podcast. They have been a family-owned company for over 45 years, and their dedicated focus on quality and consistency has grown them into the largest supplier of grapevines in both North and South America and the industry leader in nursery standards. Visit them today at SunridgeNurseries.com and mention the code Underground to receive a podcast listener discount on your vine order.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

In this final installment of the Vineyard Nutrition Essentials series, Fritz is joined by Dr. Jaclyn Fiola, Assistant Professor of Soil and Environmental Science at Delaware Valley University, to unpack the critical role magnesium plays in vineyard health and productivity. Building on prior discussions around potassium, the conversation explores how magnesium functions as a key macronutrient, particularly as the central component of chlorophyll and a driver of photosynthesis and energy transfer in grapevines.

Dr. Fiola explains that magnesium primarily originates from soil minerals, especially in darker, magnesium-rich parent materials, and that soil characteristics such as pH, texture, moisture, and cation exchange capacity influence its availability. There is a delicate balance between magnesium, potassium, and calcium, and nutrient competition can lead to deficiencies even when soil levels appear adequate.

Listeners will learn how to identify magnesium deficiency symptoms, including interveinal chlorosis in older leaves, and why these symptoms typically emerge later in the growing season. The episode also underscores the importance of accurate diagnosis through soil and tissue testing to avoid mismanagement.

Listen now to learn the important role of magnesium in your vineyard.

In this episode, you will hear:

• Magnesium as a core component of chlorophyll and photosynthesis

• Soil pH, texture, and moisture driving nutrient availability

• Competition between magnesium, potassium, and calcium

• Late-season deficiency symptoms and how to recognize them

• Importance of tissue testing for accurate diagnosis

• Pre-plant and in-season magnesium correction strategies

Follow and Review:

If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.

Resources:

Visit www.virtualviticultureacademy.com/sampling to access Fritz's how-to guides and videos for proper sampling and target nutrient values.

Listen to Dr. Jaclyn Fiola's previous podcast episode (episode 73) to learn about the role of potassium in vineyards.

Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.

Come grow with Fritz through https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.

Today's Guest:

Dr. Jaclyn Fiola is a soil scientist who specializes in vineyard soils and soil science pedagogy. She works as an Assistant Professor of Soil and Environmental Science at Delaware Valley University.

Connect with Jaclyn, follow her, and view her research.

Episode Sponsor:

Today's episode was brought to you by Vigneron Toy Store and Shellt Grow Tubes.

Thank you to Vigneron Toy Store for sponsoring today's episode. Vigneron Toy Store specializes in Harvesters, Sprayers, Frost Mitigation Equipment, Canopy Management Trimmers, and more. As grape growers themselves, they can expertly help you determine the best equipment for your specific vineyard needs. And, as a special offer for our podcast listeners, you can save 5% off in-stock machines by entering the promo code Underground on the contact form at vignerontoystore.com.

Thank you to Shellt Grow Tubes for sponsoring today's episode. Shellt makes the ultimate grow tubes for grape vines and orchard trees. Their grow tubes are reusable, recyclable, and designed to grow with your vineyard by clicking together for taller or wider coverage. I exclusively recommend Shellt Grow Tubes to the growers I work with. Visit https://www.shellt.us/ and order with the code UNDERGROUND to save 15% off all online orders, plus free shipping within the continental United States.

Episode Credits

If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.