The Major Vegetable Families
Amaryllidaceae Family – Leeks, Onions, Shallots
Brassicaceae Family – Broccoli, Cauliflower, Cabbage, Kale
Compositae Family – Artichoke, Escarole, Chicory, Cardoon, Jerusalem Artichoke, Lettuce, Sunflower
Chenopodiaceae Family – Beet, Chard, Spinach, Quinoa
Solanaceae Family Peppers, Tomatoes, Potatoes and Eggplants
Planning Your Garden for Seed Saving
Gardening starts with planning. If you want to save seed from your garden, understanding basic concepts when you are planning your garden will make seed saving much easier.
Know whether your parents plants is a hybrid or open-pollinated variety. Hybrids, which are created by crossing plants of two different varieties, generally do not produce offspring with the same traits as the parent plant. Seed saved from open-pollinated varieties, on the other hand, will produce plants identical to the parent. Heirloom seeds are open-pollinated varieties with a history of being handed down from generation to generation.
Know your plants’ scientific name [Genus and species]. Cross-pollination is the transfer of pollen between plants. To save pure, seed, you want to prevent cross-pollination between two different varieties in the same species. Planting just one variety in a species will help ensure that you save pure seed.
If you know your plants’ scientific name, you will know which ones may cross-pollinate. For example, the squash we commonly grow in our gardens could fall into one of three species: Cucurbita maxima, C. moschata, and C. pepo. These species won’t typically cross-pollinate. On the other hand, Brassica oleracea includes broccoli, brussels sprouts, cabbage, cauliflower, collards, kale and kohlrabi, all plants you might thing wouldn’t cross but actually do!
Know how your plants pollinate. Understanding how garden plants are pollinated will help you prevent cross-pollination. Some plants will self-pollinate before the flower is even open, make them less susceptible to cross-pollination. Examples of “selfers” are tomatoes, peas and beans. On occasion, insects can cross-pollinate selfers. Plants that are insect-pollinated (squash or cucumbers) or wind-pollinated (corn and spinach) are more likely to cross-pollinate.
Know what your neighbors are growing. Some varieties, especially those that are wind or insect-pollinated, need a certain distance of isolation to ensure seed purity. For example, sunflowers must be isolated 1/2-3 miles, and corn needs a distance of 2 miles. You may have to consider what your neighbors are growing.
Market mature vs. seed mature. Some fruits are market mature, or ready or eating, long before the seed is mature. Examples of this include cucumbers, eggplants, peas, beans and cabbage. Take into consideration spacing and timing when planning your garden for seed saving. For example, imagine a carrot–you full this sweet root out of the ground after about 2 months, and there is not much plant showing above ground. However, when you harvest the seed, a carrot plant can be up to 4 feet tall and one year old!
For beginners, keep it simple! Remember, some plants are easier to save seed than others. Saving seed from “selfers” is a good way to get started. Planting one variety per species can unsure your seed has not cross-pollinated. Check out “Seed to Seed” by Suzanne Ashworth, for detailed seed saving information.
Basic Seed Saving Information
Name: Cycle: Pollination: Pollinator: Isolation Distance: Seed Longevity: Notes
Bean: A: Self: 100′; 2-3 years: seeds lose vigor rapidly
Soybean: A: Self: 100′: 2-3 years: space further apart than for market crops
Beet/Chard: B: Cross: Wind: 1/2 mile: 3-5 years: beets cross with chard
Broccoli/Kale/Cauliflower: B: Cross: Insects: 1/2 mile: 3-5 years: hot water treated seeds last only one year, crossing among brassicas is complex, consult a seed saving book
Carrot: B: Cross: Insects: 1500′: 2-3 years: crosses with wild species
Celery: B: Cross: Insects: 1500′: 2-3 years:
Corn: A: Cross: Wind: 1/2 mile: 2-3 years: adequate population necessary. 200+ plants
Cucumber: A: Cross: Insects: 1500′: 5-10 years: harvest at yellow blimp stage
Eggplant: A: Self: 150′: 2-3 years
Leek: B: Cross: Insects: 1500′: 2 years
Onion: B: Cross: Insects: 1500′; 1 year
Lettuce: A: Self: 50′: 2-3 years: start indoors, needs long season for seed production
Melon: A: Cross: Insects: 1500′: 5-10 years: muskmelons will not cross with watermelons
Mustard: A: Cross: Insects: 1/2 mile: 3-5 years: crosses with wild species
Pea: A: Self: 50′: 2-3 years: do not save seed from diseased plants
Pepper: A: Both: insects: 500′: 2-3 years: some varieties cross more readily than others
Radish: A: Cross: Insects: 1500′: 3-5 years
Spinach: A: Cross: Wind: 1/2 mile: 2-3 years:
Squash/Pumpkin: A: Cross: Insects: 1500′: 2-5 years: moschata 2-3 years, pepo and maxima 3-5 years, these three species generally do not cross
Tomato: A: Self: 25-100′: 5-10 years: potato-leaf types need the greater isolation distance
Cycle: A=annual, B=biennial
Pollination: Self=self-pollinated, Cross=cross-pollinated by another plant
Isolation Distance: recommended distance by which different varieties must be separated to prevent unwanted cross-pollination.
Seed Longevity: averages, not guarantees. Seed longevity depends on the conditions under which the crop was grown and the seeds were stored.
Minimum populations: crossers require minimum populations to maintain vigor and avoid inbreeding depression. Recommended minimum number of plants: 25 cucumbers, squash, melons; 50-100 radishes, brassicas, mustards; 200 sweet corn.
Seed Storage
Keep your seed alive by storing it properly! Humidity and heat are the enemies of seed longevity. Humidity causes the quickest deterioration. Ideal moisture content for most seed is only 10-12% so store at low relative humidity. Use a sealed jar in your freezer or refrigerator for optimum storage. Once thawed seed must be planted that season. Failing that, don’t ever allow the sum of temperature plus relative humidity where seed is kept to exceed 100.
Never store in a warm, humid sunny spot. Don’t ever leave seed in a greenhouse or hoophouse, even for a few hours.
Stored properly , most seed will last for several years. A few seeds are good for only one year, such as onions, parsnips, parsley, chives, shiso, scorzonera/salsify, Batavian endive, licorice, pennyroyal, St. Johnswort, liatris, delphinium, larkspur, perennial phlox, and any pelleted or hot-water treated seed. If in doubt, try germinating a sample in moist paper towels.
Philadelphia Seed Exchange 