Q: I want to expand my native plant garden, but buying plants (even plugs) can get expensive to cover a large area, and dividing perennials is a lot of work. Can I try using seeds from my existing garden and those I trade with others?
A: Certainly, and if utilizing straight species (i.e., not cultivars), the resulting genetic variability is a big bonus and boosts resiliency in a mixed planting. If you want to purchase seed for species you don’t have, try to find suppliers that source their genetics locally, since distant populations may not be well-adapted to nuances of our conditions, especially when the species has a large natural range.
Seed companies should supply storage and germination instructions, but you can also find propagation info from good native plant books, on the web, and by asking other gardeners what’s worked well for them. After cleaning, some seed will need to be stored dry, some moist, and many will need stratification — cold exposure to gradually break down their natural chemical inhibitors that prevent premature sprouting. This can be achieved by sowing seeds outdoors or by storing seed in the fridge for several months.
Details of chilling, sowing depth, and more, will vary by species. Label everything — it’s easy to forget botanical names, habitat preferences, and details like collection, chilling start, and sowing dates. Keeping a log of successes and failures will help you improve your technique for future seasons. You can search our Maryland Grows blog and UMDHGIC YouTube channel for “seed saving,” “winter sowing,” and similar keywords for more information, tips, and demonstrations.
Q: Can I save seeds from my tomatoes and squash this year? They’ve been delicious and this would be an easier way for me to ensure I get to enjoy them again next year.
A: It depends on what you’re growing. Hybrid vegetable varieties (noted as such on their label or in a catalog, usually as “F1”) won’t “breed true,” that is, seed saved from them won’t create offspring with the same consistent traits (flavor, color, size, disease-resistance, etc.) that you enjoy in your current harvest. Vegetable varieties that aren’t hybrids (referred to as open-pollinated) will.
Open-pollinated varieties of tomatoes, beans, and peas tend to self-fertilize, so will be fine to save. Cucurbits (cucumber, summer and winter squash, pumpkin) tend to cross-pollinate via bees, so pollen from plants in neighboring yards may need to be excluded via pollinator barriers. Or, you could hand-pollinate the plant from which you want to save seed. Otherwise, you’ll get a pot-luck mix of offspring — some may be good, but others may be duds. Some crosses volunteer themselves — we often field identification queries in summer for mystery squash appearing in a compost pile or somewhere wildlife ran off with a fruit last year.
For any seed gathering, select high-quality, ripe fruits. Remember that for some vegetables, we tend to harvest before they’re truly ripe (the seed will be underdeveloped), so some of your crop may have to be sacrificed to let fruits mature fully before seed processing and storage.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Extension” to send questions and photos.