In this episode of the HighGround podcast, hosts Tom Constable and HighGround CEO Jamie Crisp visit the National Trust’s Killerton Estate in Devon to speak with Karl Emmeleus, head gardener and a long‑time supporter of HighGround’s Rural Weeks. Karl retrained from secondary‑school teaching into horticulture more than two decades ago and has worked his way up through the National Trust to manage one of its largest gardens.
He explains that Killerton’s estate spans 6,400 acres of farmland, woods and parkland nationaltrust.org.uk, while the formal garden he manages covers about 18 acres with everything from lawn care and propagation to woodland management. Karl describes how horticulture offers an almost endless variety of roles, from general gardening to specialist tree and plant work and why service‑leavers’ teamwork, adaptability and attention to detail make them well suited to the sector.
The discussion covers day‑to‑day tasks, seasonal variations, the growth of habitat restoration on estates, and entry routes such as volunteering, apprenticeships and RHS Level 2 qualifications. Karl shares practical tips on finding jobs and stresses the mental‑health benefits of working outdoors; studies show that gardening can improve mood, self‑esteem and concentration while reducing stress webmd.com. The episode closes with advice for veterans to visit gardens, talk to professionals and experience the work first‑hand.
Episode chapters & key moments:
00:00 Introduction: Tom & Jamie recap the aim of the HighGround podcast—creating an evergreen library of conversations about land‑based careers for veterans, service‑leavers and reservists.
02:13 Meet Karl Emmeleus: Karl introduces himself and explains his journey from teaching to horticulture. He retrained and joined the National Trust over 20 years ago, rising through the organisation to become head gardener at Killerton.
03:39 What is horticulture? Karl clarifies that horticulture is the professional practice of gardening; it goes far beyond cutting hedges or mowing lawns and includes plant propagation, tree care, design and public engagement.
05:01 Diverse career paths: Discussion about the many routes within horticulture—from generalist gardeners to specialists in trees, plant genera or conservation—and how interests can develop over time.
06:58 Soft skills & veterans: Jamie notes that veterans bring transferrable skills such as punctuality, health‑and‑safety awareness, teamwork and adaptability, which are highly valued in horticulture.
08:15 Killerton Estate overview: Karl describes Killerton’s 6,400‑acre estate with 18 tenant farms and woodlandsnationaltrust.org.uk. His team maintains an 18‑acre formal garden plus smaller plots around the estate with only four full‑time staff, one apprentice and around 20 volunteers.
09:30 Daily tasks & seasonal work: From early‑morning blowing and grass‑cutting before visitors arrive to dead‑heading, edging, propagation and tree work, Karl outlines how the job changes with the seasons and why no two days are the same.
10:13 Wider estate roles: Beyond gardening, Killerton employs ecologists, rangers, carpenters and countryside managers to restore habitats and plant trees—highlighting the breadth of land‑based careers. In fact, the estate has 15 tenant farms and uses hedgerows to link habitats across its 6,400 acresnationaltrust.org.uk.
13:00 Why horticulture suits veterans: Karl explains that working outside, contributing to conservation and seeing immediate results are rewarding for people leaving the services. Gardening is known to improve mood, boost self‑esteem and increase focuswebmd.com.
14:25 Qualifications & apprenticeships: Karl advises gaining practical experience first, for example through volunteering, before committing to formal study. The National Trust offers paid apprenticeships (£22k pa) that combine college study with on‑the‑job training. Recognised qualifications include the RHS Level 2 Certificate, which covers planting, pruning, propagation and maintenance skillsrhs.org.uk and provides a theoretical understanding of plant sciencerhs.org.uk.
16:00 Volunteering & getting started: Tips on approaching local National Trust properties—many welcome volunteers and offer assistant gardener roles even without formal qualifications. Karl encourages would‑be gardeners to visit gardens, meet the teams and use face‑to‑face contacts to stand out.
19:50 Challenges & rewards: Weather and wildlife (rabbits, moles, insects) are constant challenges, but positive visitor feedback and the satisfaction of nurturing plants make the work worthwhile.
22:20 Creativity & conservation: Within conservation plans, gardeners can still design borders and experiment with herbaceous plantings, while respecting the spirit of heritage sites and avoiding invasive species.
24:20 Career progression & salaries: Entry‑level gardeners (National Trust Grade 9) start at around £24k, with apprenticeships paying ~£22k. Senior gardeners and head gardeners earn in the low–mid £30k range, with higher salaries for larger teams. Ongoing training and internal leadership programmes support progression.
30:34 Job search & resources: Many horticulture jobs appear on general job boards (e.g., Indeed), but the National Trust lists roles—from apprenticeships to assistant gardeners—on its dedicated site (nationaltrustjobs.org.uk). HighGround’s Rural Weeks offer hands‑on experience and networking.
31:55 Final advice: Karl encourages veterans to talk to gardeners, experience the work through volunteering and use their military discipline and adaptability to stand out. The discussion ends on a light note about National Trust uniforms (everything is provided—except underwear!).
About our guest:
Karl Emmeleus is the head gardener at the National Trust’s Killerton Estate in Devon. Killerton is a 2,600‑hectare (6,400‑acre) estate of farmland, woods and parkland nationaltrust.org.uk. Its formal garden is known for rhododendrons, magnolias, champion trees and lawns nationaltrust.org.uk, and the estate manages 15 tenant farms and links habitats with hedges nationaltrust.org.uk. After initially training as a secondary‑school teacher, Karl retrained in horticulture, joined the National Trust and progressed to head gardener. He now mentors apprentices, leads a team of staff and volunteers, and supports HighGround’s Rural Weeks by giving veterans hands‑on experience. Follow the estate on Facebook and Instagram.
Resources & links:
- Killerton, Devon – Plan a visit, discover the gardens and learn about conservation work at Killerton nationaltrust.org.uk.
- Volunteer or work with the National Trust – Killerton relies on hundreds of volunteers nationaltrust.org.uk; explore roles and apprenticeships on nationaltrustjobs.org.uk.
- RHS Level 2 Certificates – The Royal Horticultural Society’s Level 2 Certificate in Practical Horticulture teaches planting, pruning, propagation and maintenance skillsrhs.org.uk, while the Principles of Plant Growth course provides a theoretical foundationrhs.org.uk. Completion of both leads to the combined Principles and Practices certificaterhs.org.uk.
- Gardening & mental health – Research shows that gardening improves mood, boosts self‑esteem and concentration, provides exercise and encourages social bondswebmd.com.
- HighGround – Learn about HighGround’s Rural Weeks and horticultural therapy programmes at highground‑uk.org, and explore volunteering and training opportunities for veterans.
Call to action
If this episode inspired you, please share it with a friend or colleague who might benefit. To explore horticulture first‑hand, sign up for a HighGround Rural Week or contact your local National Trust property about volunteering. You can also rate and review the HighGround podcast in your favourite app to help other veterans find these resources.