Show notes
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
Key Questions Answered
What makes a seed viable?
A viable seed is mature enough to germinate and grow into a plant, and it has remained healthy enough to survive conditions such as extreme heat, excessive moisture, and seed-borne pathogens. Seeds don't all become viable at the same moment; there is natural variation within a plant's seed production.
How do you know when cucumbers are ready for seed saving?
Choose a healthy, desirable cucumber and mark it on the vine. Leave it to mature well beyond the eating stage until it becomes large and often turns orange. The seeds should fill out rather than remain flat and immature.
Should winter squash be cured before saving its seeds?
Yes. Leaving winter squash in the field for several days after harvest maturity, particularly during warm weather, allows the seeds to finish maturing before the squash is opened. Summer squash should also be left on the plant well beyond the usual eating stage.
Can you save viable seeds from grocery-store produce?
Often, yes. Tomatoes are frequently suitable for seed saving, and bell pepper seeds may be more mature if the fruit is allowed to turn red before processing. Melons and squash may also provide useful seeds. However, seeds from hybrid or seedless varieties can produce unpredictable results.
Will seeds from an apple grow into the same kind of apple?
Usually not. Apple flowers can receive pollen from different trees, creating new genetic combinations. Growing an apple tree from seed can take three to ten years to evaluate, and the resulting fruit may be better, worse, or simply different from the original.
Is fermenting seeds necessary when saving tomatoes and cucumbers?
No. Seeds can germinate successfully without fermentation. However, wet processing and fermentation can help reduce certain seed-borne disease problems and may improve storage and handling, particularly when processing larger quantities.
How should you harvest and store bean and pea seeds?
Allow the pods to dry on the vine until they begin to open. If weather conditions make that impractical, pull the vines and hang them indoors until the pods dry completely. This helps the seeds mature and prepares them for storage.
What is the best way to harvest lettuce seeds?
Let lettuce flower and develop its characteristic fluffy seed heads. Watch for a large number of mature seed heads, then cut the stalks, turn them upside down, and shake them into a paper bag. Winnow away the fluff and chaff before storing the seeds.
Why should gardeners allow some plants to reseed naturally?
Plants can respond to their local conditions and emerge when the timing is right. By allowing crops such as basil, cilantro, lettuce, and kale to reseed, gardeners can encourage plants that are already growing successfully in their gardens.
What should you do when you're unsure whether a seed is viable?
Save it and try growing it. Bill emphasizes that seed maturity varies among species and even among individual seeds. Experimentation can reveal surprising germination potential and teach gardeners more about the resilience of plants.
How does seed diversity strengthen local food systems?
Growing many varieties helps gardeners discover which plants perform best in their particular conditions. Sharing seeds and observations through community networks helps preserve genetic diversity and makes locally adapted crops more accessible.
How does the Going to Seed program help gardeners?
Going to Seed collects seeds contributed by growers, mixes diverse varieties into regional seed-sharing collections, and distributes them with educational materials. The goal is to help gardeners discover varieties suited to their local environments while rebuilding genetic diversity.
Episode Highlights
- Viability starts with maturity. Seeds need sufficient time to develop, and harvesting too early can leave them flat, immature, or unable to germinate.
- Let vegetables mature beyond the dinner table. Cucumbers, summer squash, and winter squash need extra time on the plant or additional curing before their seeds are ready.
- Experiment with grocery-store produce. Tomatoes, peppers, melons, and other fruits can be useful seed sources, although the resulting plants may vary depending on the variety and its genetics.
- Fermentation has a purpose beyond germination. Wet processing can help address seed-borne diseases, though it isn't always necessary for home gardeners.
- Let nature do some of the work. Allowing selected plants to reseed naturally can encourage crops that are well suited to the garden's conditions.
- Save seeds even when you're uncertain. Different plants mature at different rates, and some seeds can continue developing after flowers or seed-bearing material are harvested.
- Diversity is a practical investment. Bill recommends growing as many varieties as possible to discover which ones thrive locally.
- Community seed sharing multiplies the benefits. Going to Seed and local seed libraries connect gardeners, preserve varieties, and help identify crops suited to different regions.
Calls to Action & Resources
- Seed Chat SeedChat.org: Join live conversations about seeds, seed saving, and resilient gardening.
- Going to Seed GoingToSeed.org: Explore diverse seed collections, regional seed-sharing programs, and opportunities to contribute seeds.
- Native Seeds/SEARCH Learn about traditional crop varieties and the preservation of regional seed diversity.
- Urban Farm Podcast UrbanFarm.org: Listen to conversations about growing food, saving seeds, and strengthening local food systems.
- Seed Library Network SeedLibraryNetwork.org Explore seed libraries and community resources; the episode mentions a recent Urban Farm Podcast conversation with Rebecca Newburn, approximately episode 1006.
Need a little bit of advice or just a feedback on your design for your yard or garden?
The Urban Farm Team is offering consults over the phone or zoom. Get the benefits of a personalized garden and yard space analysis without the cost of trip charges.
You can chat with Greg to get permaculture based feedback.
Click HERE to learn more!
*Disclosure: Some of the links in our podcast show notes and blog posts are affiliate links and if you go through them to make a purchase, we will earn a nominal commission at no cost to you. We offer links to items recommended by our podcast guests and guest writers as a service to our audience and these items are not selected because of the commission we receive from your purchases. We know the decision is yours, and whether you decide to buy something is completely up to you.
Our TOPPODCAST Picks 
Stay Connected
