Show Notes
In this Episode Craig LeHoullier shares his lifelong journey from childhood gardening memories to becoming a renowned heirloom tomato grower, seed saver, and plant breeder. He explains the differences between heirloom, open-pollinated, and hybrid tomatoes and why preserving tomato genetics matters for future gardeners. Craig discusses the Dwarf Tomato Breeding Project, the story behind Cherokee Purple, growing tomatoes in containers and straw bales, and the importance of learning directly from your plants. He encourages gardeners to get their hands dirty, experiment, save seeds, and enjoy gardening as a lifelong journey. Our Guest: Craig is a North Carolina-based gardener, author, and plant breeder known for his deep expertise in heirloom tomatoes. With a PhD in chemistry from Dartmouth and a 25-year career in pharmaceuticals, he later shifted full-time into gardening and seed saving. Craig is a longtime advisor to Seed Savers Exchange, and is credited with helping popularize varieties like Cherokee Purple tomatoes. He co-leads the Dwarf Tomato Breeding Project and authored Epic Tomatoes, a widely respected guide for home growers. Key Topics & Entities Craig LeHoullier and his 40-year gardening journey Heirloom, hybrid, and open-pollinated tomatoes Seed Savers Exchange Tomato seed saving and preservation The Dwarf Tomato Breeding Project Cherokee Purple tomato Tomato breeding and genetics Epic Tomatoes Straw bale gardening Container tomato growing Victory Seed Company Gardening misinformation and experimentation Food systems and food deserts Gardening as community building
Key Questions Answered What makes a tomato an heirloom? Craig defines an heirloom as a genetically stable variety that can be passed down through saved seed, with age and a meaningful history or story associated with it. What is the difference between heirloom and open-pollinated tomatoes? All heirlooms are open-pollinated, but not every open-pollinated tomato is an heirloom. Craig uses 1949, when Burpee's Big Boy was introduced, as a useful guidepost for distinguishing older heirlooms from newer open-pollinated varieties. Why are hybrid tomatoes valuable? Hybrids can combine desirable traits such as disease resistance, heat tolerance, growth habits, and productivity. Craig emphasizes that there are excellent hybrids, heirlooms, and open-pollinated varieties. How did the Dwarf Tomato Breeding Project begin? Craig and Patrina began crossing large, flavorful heirlooms with dwarf tomato varieties to create tomatoes that could be grown in smaller spaces while retaining excellent flavor and interesting characteristics. Why is Cherokee Purple important to Craig? Craig received seeds in 1990 from J.D. Green, who told him they came through a Cherokee family history in Tennessee. Craig grew the tomato, named it Cherokee Purple, and helped distribute it so the variety and its story could continue. What makes a tomato variety worth preserving? Beyond flavor and popularity, a variety may contain genetic traits that could become important for future challenges such as heat, drought, water scarcity, or emerging diseases. What is one of the biggest mistakes gardeners make with tomatoes? Craig says gardeners need to pay attention to their plants. Daily observation can reveal early signs of disease, nutritional problems, water stress, and other issues before they become serious. What is the key to successful straw bale gardening? A straw bale is conditioned with nitrogen, water, and fertilizer for roughly two weeks before planting. The bale heats up as it decomposes and provides a productive growing medium that eventually becomes useful organic matter. What tomatoes work well in small spaces? Craig recommends Sun Gold cherry tomatoes, dwarf tomatoes, and micro-dwarf varieties for containers and limited growing spaces. Cherry tomatoes can also perform well with less sunlight than many larger varieties. What is Craig's advice for beginning tomato growers? Get your hands dirty
More from The Urban Farm Podcast with Greg Peterson
On this replay of the Rosie on the House radio show Host Rome and Farmer Greg welcome Rachel Opio, founder of Little Lighthouse Farm, a certified organic urban farm in central Phoenix, Arizona, to explore how growing food in small spaces can strengthen communities and reconnect people with the land. Inspired by her late mother, Lane Bales, Rachel transformed a family garden into a productive quarter-acre farm focused on soil health, biodiversity, fresh local food, and community education. She shares practical approaches to regenerative agriculture, companion planting, seed saving, and growing food in the Sonoran Desert. Rachel also explains how small urban farms can improve access to fresh produce, preserve growing knowledge, and contribute to a stronger local food system. Her advice for beginners is simple: start with one plant, grow something you love to eat, and let your garden grow from there. Key Topics & Entities Rachel Opio — Founder and farmer at Little Lighthouse Farm in central Phoenix. Little Lighthouse Farm — Certified organic urban farm focused on nutrient-dense food, community access, and education. Farmer Greg Peterson — Urban farming educator, founder of UrbanFarm.org, and host of the Urban Farm Podcast. Urban agriculture — Growing food in residential yards, containers, and small urban spaces. Regenerative agriculture — Building soil health, increasing biodiversity, and supporting a living ecosystem. Certified organic farming — Annual inspections, detailed recordkeeping, traceability, and certification requirements. Local food systems — Connecting growers and consumers through direct sales, farm stands, restaurants, and local distributors. Soil health — Balancing nutrients, organic matter, airspace, water, and living organisms. Companion planting — Combining compatible plants, including tomatoes, basil, and marigolds, to support a diverse garden. No-till gardening — Protecting soil structure and using chickens to help cultivate garden areas. Seed saving and climate adaptation — Saving seeds suited to Phoenix's Sonoran Desert conditions. Food access and community inclusion — Accepting SNAP/EBT, WIC, and senior farmers market nutrition benefits. Pollinator stewardship — Maintaining bees, perennial flowering plants, and habitat for beneficial wildlife. Beginner gardening — Starting small with a container, herb, or favorite edible plant.
With Seed Expert Bill McDorman Join us for our monthly live Seed Chat at SeedChat.org What makes a seed viable, and how do you know when it's ready to grow? In this episode of Seed Chat, Greg Peterson of the Urban Farm Podcast joins seed expert Bill McDorman to explore the art and science of harvesting mature, viable seeds from vegetables, fruits, and wild plants. They share practical techniques for saving seeds from cucumbers, squash, tomatoes, peppers, beans, lettuce, and more, explaining when to harvest, how to dry and process seeds, and why nature's built-in diversity matters. The conversation also explores the importance of seed saving, locally adapted varieties, and community seed networks in building a more resilient food system. Their message is simple: when in doubt, save the seeds and see what happens. Key Topics & Entities Seed viability and germination testing Seed maturity and harvesting techniques Saving cucumber and winter squash seeds Harvesting seeds from grocery-store produce Seed saving from tomatoes, peppers, melons, and apples Wet seed processing and fermentation Harvesting and storing beans, peas, and cowpeas Lettuce flowering, seed collection, and winnowing Natural reseeding and letting plants self-propagate Genetic diversity and locally adapted seeds Native Seeds/SEARCH and traditional seed varieties Masanobu Fukuoka and The One-Straw Revolution Going to Seed and its seed-sharing program Community seed libraries and regional seed networks
with Jennifer Miller & Erin Torgerson In this Episode - What if small farmers could build trust with their customers without taking on the cost and paperwork of USDA Organic certification? That’s the idea behind Certified Naturally Grown (CNG), a grassroots organization helping farmers show customers how they grow their food. In this episode, Greg Peterson sits down with Jennifer Miller and Erin Torgerson from CNG to talk about how peer inspections, transparency, and a strong farming community help make that possible. Along the way, they explore the importance of local food, saving seeds, sharing knowledge, and making good food more accessible to everyone. Our Guests: Jennifer is the interim executive director of Certified Naturally Grown. From working on farms around the world to running her own farm and directing two food hubs, Jennifer's hands-on experience proves one thing, food is her love language. Erin is the communications and certification coordinator of Certified Naturally Grown. While filming a student documentary about a local farm-to-table restaurant, Erin caught her first glimpse of a biodiverse small-scale farm and hasn't looked back. Certified Naturally Grown is an organization that offers peer review certification to farmers and beekeepers producing food, flowers, and fiber for their local communities by working in harmony with nature without relying on synthetic chemicals or GMOs. Key Topics Certified Naturally Grown (CNG): A farmer-led certification program built around trust, transparency, and community. CNG and USDA Organic: How CNG offers an alternative for farmers who find USDA Organic certification too expensive or complicated. Peer inspections: Farmers visit and review one another’s operations, creating opportunities to learn as well as verify growing practices. Participatory Guarantee Systems (PGS): A community-based approach to building confidence in how food is produced. Making farming work financially: The challenges small-scale farmers face when balancing good growing practices with the realities of running a business. Five CNG certification programs: Produce and flowers, livestock, apiaries, mushrooms, and aquaponics. Transparency for consumers: How customers can learn more about participating farms and review inspection information. Local food systems: Why connecting farmers, consumers, and communities matters. Food hubs and distribution: The challenges of getting locally grown food to the people who want it. Natural beekeeping: Approaches to raising bees with attention to their health and well-being. Aquaponics: Growing food through a system that combines fish and plants. Seed saving: Preserving seed varieties and helping farmers maintain greater control over their growing systems. Farmer education and mentorship: How sharing experience can help new and established growers succeed. Understanding the food system: Why building a better food future involves more than just how we grow food.
In this Episode Farmer Greg welcomes returning guests Shawn and Beth Dougherty, homesteaders with 40 years of experience growing food and building a farm ecosystem with minimal outside inputs. They discuss their philosophy of homesteading, living soil, biological wealth, and the patterns that allow a farm to generate its own fertility and abundance. Their new book, One Cow Revolution, is an in-depth instruction manual for the family dairy cow, drawing on decades of experience with cows, goats, grazing, milk, and farm systems. Shawn and Beth have been homesteading for the last 40 years. They speak all over the country on sustainable farming, teaching whoever will listen how to grow food without inputs. They grow 95% of what they eat and what their animals eat, and the heart of their sustainable homestead is their grass-fed dairy cow. They joined us for the first time on episode 147 all the way back in October 2016. Key Topics Homesteading as producing food for your family while improving the soil How to grow food without relying on outside inputs Creating living soil is biological wealth How to build self-fertile farm ecosystems The relationship between plants, animals, soil, and sunlight Rotational grazing and working with natural patterns Learning through failure, mistakes, and setbacks The role of dairy cows in a homestead One Cow Revolution The Independent Farmstead Micrograzing and small-scale grazing Grass-fed dairy, milk, cheese, butter, whey, and buttermilk Chickens and pigs as part of the farm nutrient cycle Family, food, farming, and passing knowledge between generations
In this Episode - What if the key to growing healthier, more productive gardens isn’t more fertilizer, but healthier living soil? Ben Lederer, co-founder of Regenerative Soil Company in North Phoenix, joins Greg to explore how compost, worm castings, mulch, and beneficial biology can transform the soil beneath your garden. You’ll learn simple ways to start composting, use kitchen scraps and chickens to build a regenerative cycle, and improve your soil while reducing reliance on synthetic inputs. Ben and Greg also share practical ideas for taking one small step toward a healthier garden and a more resilient community. Our Guest: Ben is the co-founder of Regenerative Soil Company, a small batch amendment company based in North Phoenix. A longtime gardener, chicken keeper, and compost enthusiast, Ben is passionate about helping people grow healthier plants naturally through worm castings, regenerative gardening practices, and living soil biology. He also works in turf grass management and enjoys teaching practical, approachable ways to build healthy soil at home Key Topics Ben Lederer Regenerative Soil Company Worm castings Living soil biology Regenerative gardening Composting Green mulch and cowpeas Chickens and backyard food systems Local soil amendments Turf grass and soil management Permaculture and closed-loop gardening Arizona Worm Farm Community gardening The Worm Farmer’s Handbook