Seed Saving

Arugula: Arugulas will cross-pollinate. Separate varieties by ¼ mile. Allow plants to bolt and form seed stalks. Seedheads may need to be protected from bird damage and rain when drying on the plants. Seeds are produced over a 2-3 week period and will require repeated harvesting.

Beans: Bean flowers are self-pollinating and almost never cross-pollinate. As a precaution never plant two white seeded varieties side-by-side if you intend to save seed because crossing may occur but not be visible. It is always best to save seed from plants that ripen first and are free from disease. Harvest seed pods when completely dry, crush in a cloth or burlap sack and winnow the seeds from the chaff.

Beet: Biennial. Beets will cross-pollinate. Varieties must be separated by ½ mile from other beets the second year when going to seed. Beets are fairly frost tolerant and will overwinter in mild climates if well mulched. In northern climates trim leaves to 2″ and store roots in slightly damp sawdust or sand in a root cellar over the winter. Roots store 4-6 months at 32-40° F. Replant in the spring and harvest seed heads when dry.

Broccoli: Biennial. Broccoli will cross-pollinate with all other Brassica oleracea, so isolate by 1 mile the second year when going to seed. Do not harvest heads on plants you intend to save for seed. Carefully dig the plants and pot them in sand. Store plants between 32-40° F. Plant back out in early spring and allow to bolt. Harvest seed pods when dry and clean by hand.

Carrots: Biennial. Carrots will cross-pollinate, so isolate ¼ mile from other carrots and Queen Anne’s Lace the second year when going to seed. Dig up carrots in the fall before a hard frost. Trim the tops to 1” and store roots in slightly damp sawdust, sand or leaves in a root cellar over the winter. Replant in the spring and harvest seed heads when dry.

Cauliflower: Biennial. Cauliflower will cross-pollinate with all other Brassica oleracea, so isolate by 1 mile the second year when going to seed. Do not harvest heads on plants you intend to save for seed. Carefully dig the plants and pot them in sand. Store plants between 32-40° F. Plant back out in early spring and allow to bolt. Harvest seed pods when dry and clean by hand.

Cabbage: Biennial. Cabbage will cross-pollinate with all other Brassica oleracea, so isolate by 1 mile the second year when going to seed. Do not harvest heads on plants you intend to save for seed. Carefully dig the plants and pot them in sand. Store plants between 32-40° F. Plant back out in early spring and allow to bolt. Harvest seed pods when dry and clean by hand.

Corn: All corn varieties are wind-pollinated and will cross-pollinate with each other. Varieties should be hand-pollinated or isolated by 1 mile to ensure purity. Allow ears to dry on the plants, harvest and shell.

Cucumbers: Cucumbers will cross-pollinate, so isolate ¼ mile from other cucumbers. Fruits for seed should ripen past edible stage and begin to soften and turn yellow. Cut lengthwise, scoop out seeds, wash clean and dry. Seeds are dry when they break instead of bending.

Eggplant: Eggplants will cross-pollinate, so isolate ¼ mile from other eggplants or plant in insect-proof cages covered with screen. Let the fruits grow far past maturity. Seeds are much easier to remove from overripe fruits. Most seeds are brown and are usually located in the bottom portion of the fruit.

Gourds: Hard-shelled gourds will cross-pollinate, so isolate 1/4 mile away from other L. siceraria or hand pollinate. When dry, the gourds can be broken or cut open and the seeds separated from the dry pulp. Dry and wet gourd pulp can irritate skin and the respiratory tract. Use caution when cleaning seed.

Kale: Biennial. Kale will cross-pollinate with all other Brassica oleracea, so isolate by 1 mile the second year when going to seed. Do not harvest heads on plants you intend to save for seed. Carefully dig the plants and pot them in sand. Store plants between 32-40° F. Plant back out in early spring and allow to bolt. Harvest seed pods when dry and clean by hand.

Lettuce: There is only a slight chance of cross-pollination between lettuces. As a precaution separate by 25′ from other varieties that are going to seed. Allow plants to bolt and form seed stalks. Seedheads may need to be protected from bird damage and rain when drying. Seeds are produced over a 2-3 week period and will require repeated harvesting.

Lima Beans: Lima beans will cross with other limas, but not common garden beans, Phaseolus vulgaris. To ensure absolute purity, isolate from other blooming varieties by 1 mile. It is always best to save seed from plants that ripen first and are free from disease. Harvest seed pods when completely dry, crush in a cloth or burlap sack and winnow the seeds from the chaff.

Melons: Melons will cross-pollinate, so isolate ¼ mile from other “melons” (cantaloupes, muskmelons, honeydew, snake melon and Armenian cucumbers will all cross). Always save seeds from disease-free, early ripening melons. Wash seeds from ripe melons in a strainer and dry. Seeds are ready to store when they break instead of bend.

Okra: Okra’s large decorative blossoms are cross-pollinated by insects very easily. Varieties can be kept pure by covering blossoms with cloth bags before they open, or you can isolate varieties by 1 mile from each other. Allow the okra pods to turn brown and dry on the plant. Harvest before seedpods split open enough to drop seeds onto ground.

Onion: Biennial. Onions cross-pollinate and should be isolated by 1 mile from other onions going to seed. Select only the best bulbs for seed. Bulbs store 3-6 months at 32-45° F. Plant out bulbs in early spring and allow them to form seed heads. When the heads start to dry, cut off, dry further and thresh.

Peas: Peas should be separated by 50′ to ensure pure seed. Select the healthiest plants for seed. Allow pods to dry on the plant before harvesting and separate seeds from pods by hand. If birds start eating the seeds before the pods are completely dry, they can be harvested slightly green and brought indoors to dry.

Peppers: Peppers will cross-pollinate, so separate by at least 500′ or plant in insect-proof cages covered with window screen. Select peppers that are ripe, fully colored and show no signs of disease to save for seed. Remove seeds off core and place on a paper plate to dry.

Corn: All corn varieties are wind-pollinated and will cross-pollinate with each other. Varieties should be hand-pollinated or isolated by 1 mile to ensure purity. Allow ears to dry on the plants, harvest and shell.

Radish: Radishes will cross-pollinate and must be isolated by ½ mile or planted in insect-proof cages covered with screen. Radish seed stalks will grow up to 3′ tall. Always discard the early bolting plants, since they are not the best plants to save for seed. The seed stalk is harvested when the stalk and pods are dry. Seeds can then be separated by hand.

Runner Bean: Runner beans will cross-pollinate with other runner beans. Varieties must be separated by at least ½ mile to ensure pure seed. Another option for raising pure seed is to bag the blossoms before they open with a cloth bag. It is necessary to “trip” or shake the blossoms daily to release the pollen, imitating bee activity.

Soybean: Soybean flowers are self-pollinating and almost never cross-pollinate. To ensure absolute purity, separate by the length of the garden from other soybeans. It is always best to save seed from plants that ripen first and are free from disease. Harvest seed pods when completely dry, crush in a cloth or burlap sack and winnow the seeds from the chaff.

Spinach: Spinach will cross-pollinate with wind-blown pollen from other spinach varieties. Commercial seed crops are separated by 5-10 miles to ensure purity, but home gardeners can reduce that distance. Harvest seeds when they are completely dry on the plant. It may be necessary to wear leather gloves because the seeds can be very prickly.

Squash: Squash within the same species will cross-pollinate, so isolate species by ¼ mile. Seeds should be taken from fruits that have gone past maturity by 3 weeks. Remove seeds, wash and let dry. (Note: There are four species of squash: C. maxima, C. mixta, C. moschata and C. pepo. This allows you to grow four different species of squash and save pure seed in the same garden.)

Sunberry: Take ripe fruits and crush them in a bowl. Add water to the bowl and the seeds will sink and the skin and pulp will float. Separate the contents and wash the seeds in a strainer. Allow seeds to dry.

Swiss Chard: Biennial. Varieties must be separated by ½ mile from all other Beta vulgaris when going to seed. Will overwinter in mild climates if well mulched. In northern climates trim leaves to 2″ and store roots in sawdust or sand in a root cellar. Roots will store 4-6 months at 32-40° F. Replant in the spring and harvest seed heads when dry.

Tomato: Cross-pollination between modern tomato varieties seldom occurs, except in potato leaf varieties which should be separated by the length of the garden. Do not save seeds from double fruits or from the first fruits of large-fruited varieties. Pick at least one ripe fruit from each of several plants. Squeeze seeds and juice into a strainer and wash, spread on a paper plate and dry.

Tomatillo: Tomatillos will not cross-pollinate. Select fully ripe fruits to save for seed. Pick at least one ripe fruit from each of several plants. Squeeze seeds and juice into a strainer and wash, spread on a paper plate and dry.

Watermelon: Watermelons will cross-pollinate. Separate varieties by ¼ mile or hand-pollinate. Always select disease-free early maturing melons to save for seed. Remove seeds from ripe melons, thoroughly wash in a strainer and dry.

Jelly Melon: Jelly Melon will not cross with Cucumbers, Cucumis sativus or Melons, Cucumis melo. Fruits for seed should ripen past edible stage and begin to soften. Cut lengthwise, scoop out seeds, wash clean and dry. Seeds are dry when they break instead of bend.

Malabar Spinach: Malabar Spinach will not cross-pollinate with garden spinach, Spinacia oleracea. If two distinct
strains of Basella rubra are being grown, isolate by 1/4 mile or cage to ensure purity. When seed capsules turn from green to brown the seeds are ready to pick.

Garden Huckleberry (Solanum melanocerasum): Garden Huckleberries do not cross-pollinate. To save seed simply take ripe fruits and crush them in a bowl. Add water to the bowl and the seeds will sink and the skin and pulp will float. Separate the contents and wash the seeds in a strainer. Allow seeds to dry and store in a cool dry area.

Flowers and Herbs by Latin Names

Saving seed from flowers and herbs: Most flowers and herbs are self-seeding and volunteer. Seed must be harvested from dry pods before they shatter, usually 2-3 weeks after flowering. Dry the seeds in a shaded area for one week, then seal in an air-tight container and store under refrigeration.

Agastache foeniculum (Lavender Hyssop): Collect the seeds after seedheads turn brown and can be easily crushed by hand. Carefully clip seedheads with pruning shears to prevent seed loss due to shattering. When dry, seeds should fall readily from the heads.

Allium schoenoprasum (Common Chives): Chives are a perennial producing seed each season. Chives will not cross with any other Alliums. The purple blooms are insect pollinated and then go on to form seed heads. When the heads start to dry, cut off, dry further and thresh.

Amaranthus caudatus/cruentus/gangeticus (Amaranth): The hundreds of small sand-like seeds are contained in the rope-like trusses. When the trusses start to dry, pick and dry further in a well protected area.

Borago officinalis (Borage): Borage is extremely easy to save seed from. Just keep a close eye on the blooms and when they begin to fade and turn brown, pick the seeds. Be sure to get them before they fall as Borage is very good at seeding itself for the next season, even without your help.

Coriandrum sativum (Cilantro): Cilantro, will cross-pollinate with other varieties of cilantro so varieties must be separated by ½ mile while flowering. Seeds can be harvested when they are dry on the plant.

Echinacea purpurea (Coneflower): Coneflowers will produce lots of seed but you must beat the birds. When the blooms dry out, cut them off and hang upside down in bunches. The seeds are contained in the heads between the spikes. Once the heads are dry and crisp, they can be lightly hand-crushed, with gloves on for protection, and the seed winnowed from the chaff.

Helianthus annuus & cucumerifolius (Sunflowers): Sunflowers will cross-pollinate and must be separated by ½ mile to ensure pure seed. Harvest the heads when they have completely filled out, lost all of their petals and the backs begin to turn brown. It may be necessary to cover heads to protect them from birds. Allow to dry in a protected area away from birds and then shell by hand.

Lupinus perennis (Lupine): When seed pods begin to turn yellow and the seeds loosely rattle inside when shaken, they are ripe. Pick and finish drying in a well protected area.

Nepeta cataria (Catnip): Seeds are ready to harvest when the blooms begin to turn brown and dry. When the heads are completely dry, gently crush the heads between your hands and then carefully winnow away the chaff.

Nicotianu alata & sylvestris (Tobacco): Very easy for seed savers. When the blooms fade, a seedpod is formed at the base of the bloom, turning from green to brown. Once the seedpod turns brown, cut off and allow to completely dry before removing the hundreds of small sand-like seeds.

Ocimum basilicum (Basil): Basil will cross-pollinate with other varieties of basil and must be separated by 150′ while flowering. Plants form seed capsules containing four seeds. Allow seed capsules to dry, then harvest and separate by hand.

Pimpinellu anisum (Parsley): Parsleys will cross-pollinate, so isolate by 1 mile the second year when going to seed. Dig up parsley roots in the fall before a hard frost. Trim the tops to 2″ and store in sawdust, sand or leaves. Parsley roots will store 3-4 months when kept between 32-40° F. Plant out in the early spring. Harvest seed heads when dry, and separate by hand.

Rudbeckia hirta (Black-Eyed Susan): Seeds are ready to harvest when the blooms begin to turn brown and dry. When the heads are completely dry, gently crush the heads between your hand and then carefully winnow away the chaff.
Salpiglossis sinuata (Painted Tongue): Very easy for seed savers. When the blooms fade, a seedpod is formed, turning from green to brown. Once the seedpod turns brown, cut off and allow to completely dry before cracking open and removing the hundreds of small sand-like seeds.

Salvia officinalis (Culinary Sage): Seeds are ready to harvest when the blooms begin to turn brown and dry. When the heads are completely dry, gently crush the heads between your hands and then carefully winnow away the chaff from the seeds.

Tagetes patula/tenuifolia (Marigold): Marigolds will produce lots of seed in a similar fashion to a Zinnia or Calendula. When the blooms dry out, cut them off and hang upside down in bunches. The seeds are contained in the heads and, once dry and crisp, can be lightly hand-crushed and winnowed from the seed chaff.

Zinnia elegans (Zinnia): Zinnias will cross-pollinate. Gardeners should only grow one variety at a time to save pure seed, or isolate varieties by ¼ mile. Seeds are ready to harvest when the blooms begin to turn brown and dry. The seeds are contained in the very center. When the heads are completely dry, gently crush the heads between your hand and then carefully winnow away the chaff.

For additional seed planting instructions, A-Z Guide to Growing Flowers: from Seed to Bloom by Eileen Powell contains detailed techniques for over 600 annuals, perennials, and bulbs.