Seed Saving Advanced
Corn, Cucumber, Muskmelon, Radish, Spinach, Squash/Pumpkin.
The experienced seed saver’s vegetables produce seed the season they are planted but require separation to keep unwanted cross-pollination from taking place
Corn – Zea mays
PLANT: Female corn flowers are pollinated predominately by the wind, rarely by insects. Pollen is light and can be carried great distances. For purity, separate two varieties pollinating at the same time by at least 1 mile. Reasonable results are obtained with separation of 1000 feet.
FLOWER: Corn is monecious, producing separate male and female flowers on each plant. Male flowers appear as tassels on the top of corn stalks and female flowers are pollinated via the silk emerging from each ear.
INBREEDING DEPRESSION: Corn is susceptible to intense inbreeding depression. If seed is saved from too few plants, subsequent plants may be short, mature late and produce few ears. Grow at least 200 plants and save the seeds from at least 100 of the best.
HARVEST: Corn seed is usually ready to be harvested 4-6 weeks after eating stage.
PROCESS: Process all but very large amounts of seed by gripping dried ears by hand and twisting allowing kernels to fall into container. Any remaining silk and chaff can be winnowed.
Cucumber – Cucumis sativus
(All cucumbers except Armenian cucumbers which are Cucumis melo)
PLANT: Separate two different cucumber varieties by at least 1/2 mile, or segregate by time to ensure purity. Experienced, home, seed savers can grow more than one variety at a time in a single garden by using hand pollinating techniques.
FLOWER: Cucumbers are mostly monoecious with separate male and female flowers on each plant. Female flowers can be identified by locating the ovary (a small looking cucumber) at the base of the flower. Cucumber vines will produce the greatest amount of female flowers when day length shortens to approximately 11 hours per day. Fruits will be aborted during dry spells and very hot weather.
INBREEDING DEPRESSION: Although inbreeding depression is not usually noticeable in cucumbers, seeds should be saved from at least 6 cucumbers on 6 different plants.
HARVEST: Cucumbers raised for seed cannot be eaten. They should be left to ripen at least 5 weeks after eating stage until they have turned a golden color.
PROCESS: Slice fruit lengthwise and scrape seeds out with spoon. Allow seeds and jelly-like liquid to sit in jar at room temperature for 3 or 4 days. Fungus will start to form on top. Stir daily. Jelly will dissolve and good seeds will sink to bottom while remaining debris and immature seeds can be rinsed away. Spread seeds on a paper towel or screen until dry. (See instructions for tomato.)
Muskmelon – Cucumis melo
Divided below into seven separate groups because of similar features. All C. melos varieties in all groups will cross with each other. They will not cross with watermelons which are Citrullus vulgaris.
Indorus: honeydew, crenshaw, casaba
Conomon: Asian, pickling melons
Dundaim: pocket melon
Cantalupensis: true cantelopes (without netted skin)
Flexuosus: Armenian cucumbers
Reticulatus: Persian melons, muskmelons with netted skin and orange flesh
Chito: orange melon, garden lemon melon
PLANT: Separate two different muskmelons by at least 1/2 mile or separate by time to ensure purity. Experienced, home, seed savers grow more than one variety at a time in a single garden by using hand pollinating techniques. Muskmelon flowers are small and relatively difficult to hand pollinate.
FLOWER: Muskmelons are mostly monoecious with separate male and female flowers on each plant. Female flowers can be identified by locating the ovary (a small looking melon) at the base of the flower. The early flowers are the most likely to be successfully pollinated and eventually produce seeds.
INBREEDING DEPRESSION: Not usually a problem with muskmelons.
HARVEST: Muskmelon seed is mature and can be harvested from ripe and ready to eat muskmelons.
PROCESS: Simply rinse seeds clean, dry with towel and spread on board or cookie sheet to complete drying.
Radish – Raphanus sativus
PLANT: Separate different varieties being grown for seed at the same time by at least 1/2 mile to ensure purity. Satisfactory results for home gardeners require no more that 250 feet of separation. As radishes cannot self-pollinate, pollen must be carried by insects from plant to plant.
FLOWER: Radishes produce annual flowers which require pollination by insects, primarily bees.
HARVEST: Harvest 3′ tall stalks containing seeds pods when pods have dried brown. Pull entire plant and hang in cool, dry place if all pods are not dried at the end of the growing season.
PROCESS: Open pods by hand for small amounts of seed. Pods that do not open when rubbed between hands can be pounded with hammer or mallet. Winnow to remove remaining chaff.
Spinach – Spinacia oleracae
PLANT: It is probably best to grow seeds for only one variety of spinach at a time. Remove plants which bolt first, and thin remaining plants to 8″ for seed production. Leave one male plant for each two females to ensure pollination.
FLOWER: Spinach is “dioecious”, with male and female flowers on separate plants. Flowers are wind pollinated by spinach’s dust-like, powdery pollen which can be carried for miles.
HARVEST: Some outside leaves can be harvested for eating without harming seed production. If possible, wait until all plants have dried brown. Pull entire plant and hang in cool, dry place if necessary at the end of the growing season.
PROCESS: Strip seeds in upward motion and let them fall into container. Chaff can be winnowed. Use gloves for prickly-seeded types.
Cucurbita maxima varieties with large, hairy leaves, long vines and soft, hairy stems and include: banana squashes, buttercups, hubbards and marrows
Cucurbita mixta varieties with large, hairy leaves, long vines and hard, hairy stems and include the cushaws
Cucurbita moschata varieties similar to C. mixta with flaring stems at the fruit and large, green sepals surrounding the flowers and include: butternuts
Cucurbita pepo varieties with prickly stems and leaves with a hard, five-angled stem and include: acorn squashes, cocozelles, pumpkins, crooknecks, scallops, spaghetti squashes and zucchinis
PLANT: Squashes from different species (see above) can be grown next to each other. Separate different squash varieties in the same species by at least 1/2 mile to ensure purity. (Some crossing between C. mixta and C. moschata has been reported recently.) Experienced, home, seed savers grow more than one variety in a single garden by using hand pollinating techniques. Squash flowers are large and relatively easy to hand pollinate.
FLOWER: Squashes are monoecious with male flowers and female flowers on each plant. Female flowers can be identified by locating the ovary (a small looking squash) at the base of the flower. (Some female flowers have stamens.)
INBREEDING DEPRESSION: Not usually noticed in squash and pumpkins.
HARVEST: Squash must be fully mature before harvested for seed production. This means that summer squashes must be left on the vine until outer shell hardens. Allow to cure 3-4 additional weeks after harvest to encourage further seed ripening.
PROCESS: Chop open hard-shelled fruits and scoop out seeds. Rinse clean in wire strainer with warm, running water. Dry with towel and spread on board or cookie sheet to complete drying
Beet/Swiss Chard, Cabbage Family, Carrot, Escarole/Frissee, Onion,Radicchio/Endive, Turnip/Chinese Cabbage.
Beet/Swiss Chard – Beta vulgaris
PLANT: Grow seed for only one variety of beet or Swiss chard at any one time.
FLOWER: Beets and Swiss chard produce perfect flowers. Pollen is light and can be carried for miles by the wind.
INBREEDING DEPRESSION: Save seed from at least 6 different beets to ensure genetic diversity and vigor.
HARVEST: Cut 4′ tall tops just above the root when majority flowering clusters have turned brown. Tops can be stored in cool, dry locations for 2-3 weeks to encourage further seed ripening.
PROCESS: Small quantities of seed can be stripped by hand as seed matures. Large numbers of tops can be put into a cloth bag and stomped or pounded. Chaff can be winnowed.
Cabbage Family – Brassica oleracea
Includes broccoli, brussels sprout, cauliflower, cabbage and kale.
PLANT: All vegetables and varieties in this large species will cross with each other. Separate different varieties at least 1000 feet for satisfactory results or at least 1 mile for purity. Caging with introduced pollinators or alternate day caging is also recommended in small gardens.
FLOWER: Flowers are perfect, most of which cannot be self-pollinated. Necessary cross-pollination is performed by bees. The stigma becomes receptive before the flower opens, and pollen is shed hours after the flower opens.
INBREEDING DEPRESSION: Plant at least 6 different plants to protect vigor and ensure a reasonable amount of genetic diversity.
HARVEST: Broccoli, cauliflower, cabbage and kohlrabi heads grown for seed should not be trimmed for consumption. Brussels sprouts, collards and kale can be lightly trimmed for eating without affecting quality seed production. If small amounts of seeds are wanted, allow individual pods to dry to a light brown color before picking and opening by hand. Lower pods dry first followed by those progressively higher on the plant. For larger amounts of seeds pull entire plant after a majority of pods have dried. Green pods rarely produce viable seeds even if allowed to dry after the plant is pulled.
PROCESS: Smash unopened pods in cloth bag with mallet or by walking on them. Chaff can be winnowed.
Carrot – Daucus carota
PLANT: Separate different varieties at least 1/2 mile to ensure purity. (Queen Anne’s Lace or wild carrot will cross with garden carrot.) Alternate day caging or caging with introduced pollinators allows two or more varieties to be grown for seed in small gardens.
FLOWER: Carrots produce perfect flowers that are cross-pollinated by a number of insects. Flowers are arranged in round, flat groups called umbels.
INBREEDING DEPRESSION: Carrots can exhibit severe inbreeding depression. Save and mix seed from as many different carrots as possible.
HARVEST: For small amounts, hand pick each umbel as it dries brown. Large amounts of seed can be harvested by cutting entire flowering top as umbels begin to dry. Allow to mature in cool, dry location for an additional 2-3 weeks.
PROCESS: Clean small amounts by rubbing between hands. Larger amounts can be beaten from stalks and umbels. Screen and winnow to clean. Carrot seed is naturally hairy or “bearded”. Debearding in the cleaning process does not affect germination.
Onion – Allium sp.
Varieties within each onion species will cross with each other. Crosses between species although not common, are possible.
Allium schoenoprasum: Common chives
Allium tuberosum: Garlic chives
Allium fistulosum: Japanese bunching onions (Occasional crossing between A. fistulosum and A. cepa has been observed.)
Allium cepa comprised of three groups: Aggregatum includes shallots, multiplier onions and potato onions; Cepa our biennial, common storage and slicing onions; Proliferum includes the Egyptian or walking onions.
PLANT: Separate from other flowering Alliums of the same species at least 1000 feet for satisfactory results or at least 1 mile for purity. Caging with introduced pollinators or alternate day caging is also recommended in small gardens.
FLOWER: The Alliums produce perfect flowers, most of which are cross-pollinated because stigmas in each flower become receptive only after pollen in that flower is shed. Flowers in an individual umbel open and shed pollen at different times so crosses can and do occur on the same plant. Cross-pollination is performed mostly by bees.
INBREEDING DEPRESSION: Onions display a fair amount of inbreeding depression after two or three generations of self-pollination. Save and mix the seeds from at least two different plants.
HARVEST: Clip umbels as soon as majority of flowers have dried. Seeds will start dropping from some flowers at this time so check often. Allow to dry in cool, dry location for up to 2-3 weeks.
PROCESS: Fully dried flowers will drop clean seeds naturally. For small amounts, rub remaining flowers to free seeds. For larger amounts, rub heads over screens. Winnow to remove remaining debris.