Washburn's Community Seed Bank
@ the Washburn Public Library
Sponsored by: the Seed Savers Alliance
Bee-pollinated members of the Squash family (Cucurbitaceae), require up to a mile for distance isolation. Different species of Cucurbitaceae do not cross-pollinate, so one variety from each species can be grown together without danger of crossing. For instance, one variety of crookneck or zucchini (Cucurbita pepo), one butternut or acorn squash (Cucurbita moschata), one watermelon (Citrullus vulgaris), one cantaloupe or muskmelon (Cucumis melo), one luffa (Luffa aegyptiaca), a hard gourd (Lagenaria siceraria) and a cucumber (Cucumis sativus) could all be grown together without crossing each other.
Find out from your seed company which species your varieties belong to, or consult Suzanne Ashworth's Seed to Seed for a comprehensive listing of Cucurbitaceae varieties and the species to which each belongs (there are no reliable, general rules for non-botanists to determine species).
Insect-pollinated and are self-infertile, if Cucurbits are isolated by caging, bees must be allowed to reach and pollinate the different varieties on alternating days.
Cucurbits can also easily be pollinated by hand (use pollen taken from the same variety). After hand-pollinating the flowers, replace the cages, or bag or tape individual flowers shut to prevent further pollination. For more detail, see Seed to Seed or check out the video tutorial on cucurbits under the resources tab.
Squashes should be fully mature before harvesting—for summer and other soft squashes, this is well past the eating stage. Harvest when skins are hard and leathery. Melons should be fully ripe before they are picked, as some will not complete ripening of their seeds if they are picked too soon. Harvest melons only after the vine tendril nearest the individual melon in question has dried and withered, and wait another 3 weeks before opening the melon to harvest the seeds. Clean the seeds through fermentation.
Allow dry-seeded members of the Cucurbit family (i.e., gourds, luffa) to dry on the vines until the shells are dried and the seeds inside rattle if shaken. Open the gourd and clean the seeds by winnowing.
After harvesting wet-seeded Squash family fruits, store the unopened fruits for another 20 days before removing the seeds. This is because some squash family seeds gain in size and viability for 20 days after harvesting. After the 20 day waiting period has passed, cut the fruits open and remove the seeds to prepare them for storage.
Squash seeds can be fermented for higher germination and better disease-resistance (don't ferment seeds if they appear to have already naturally fermented while waiting in the wet fruit, as evidenced by the smell and appearance of the seeds and pulp).
After fermentation, clean the seeds by pouring off pulp and dead seeds (seeds which will float are dead and should be discarded). Use the same cleaning directions as for tomato seeds. Whether you've fermented the seeds or not, rub them underwater between your fingers gently but thoroughly while cleaning them, to remove the naturally occurring gel from their coats. Dry the cleaned seeds on a shiny surface (they will stick to paper) until they are brittle, but—as always!—do not use heat.
Seed Saving Tips
Quoted from the online Guide to Saving Vegetable Seeds
Pumpkins
Pumpkins can belong to either C. maxima or C. pepo. Varieties within these species will cross each other, but C. maxima will not cross C. pepo. Find your pumpkins' species from the seed company where you purchase them, or look them up in Suzanne Ashworth's excellent seed saving resource, Seed to Seed.
Pumpkins produce wet seeds. Store fully-ripe pumpkins for 3 weeks after harvesting before removing and cleaning the seeds.
Pumpkin seeds, like those of other members of the Squash Family, benefit from fermenting after being removed from the fruit—see Why Ferment Some Seeds?.
Pumpkin seeds will keep for 5 or more years if properly stored.
Watermelons
Watermelons will cross other watermelons and varieties should be separated by ½ mile. Watermelons produce wet seeds and should be allowed to ripen to past the eating stage before harvesting, since seeds do not continue ripening significantly after melons are harvested. Pick after the tendril nearest the melon has completely withered and dried, then store an additional 3 weeks before removing and cleaning the seeds.
Watermelon seeds will remain viable for 5 or more years if properly stored.
Organic Howden Pumpkin
The original Jack O’ Lantern! Rich orange color with deep ridges and good, sturdy handles. Weighs 25 lbs on average. Sizes up reliably and is tolerant to Black Rot. Developed in the Berkshires of Massachusetts in the late 60's by John Howden, it remains the most popular pumpkin in its class among both commercial growers and home gardeners. (Cucurbita pepo)
Seed Planting Depth: 1/2-1 inch
Seed Spacing: 3 seeds/ft
Days to Germination: 7-14
Plant Spacing After Thinning: 24 inches
Plant Height: 24-36 inches
Days to Maturity: 115
Seed Saving Difficulty: Easy
Organic Burgess Buttercup Squash
Dark green skin with a gray button on the blossom end. Golden orange, stringless flesh and a sweet, rich flavor have made this squash a long-time New England favorite. Typically produces 10-12 fruits of 3-5 lbs each per plant. Vines can reach 15’ long. This is our HMS improved strain with a high percentage of clean, non-warty and uniform squash. (Cucurbita pepo)
Seed Planting Depth: 1/2-1 inch
Seed Spacing: 3 seeds/18 inches
Days to Germination: 7-14
Plant Spacing After Thinning: 18 inches
Plant Height: 24-30 inches
Days to Maturity: 95
Seed Saving Difficulty: Easy
Organic Honey Nut Butternut Squash
From Cornell’s Vegetable Breeding Institute comes this specialty sure to gain attention. This 4-5” long mini-butternut is a dark, healthy, orange-buff. Smaller than Ponca with a much more uniform butternut shape. Simply cut in half and bake! Shows moderate to high levels of field resistance to Powdery Mildew; able to ripen to full maturity with a high-sugar content. Stores well. Note: Fruit initially appears dark green when immature and ripens to deep orangey-tan color. Final coloring can be slow to develop under cool conditions. Early planting is recommended. (Cucurbita moschata)
Seed Planting Depth: 1/2-1 inch
Seed Spacing: 3 seeds/18 inches
Days to Germination: 7-14
Plant Spacing After Thinning: 18 inches
Plant Height: 24-30 inches
Days to Maturity: 100
Seed Saving Difficulty: Easy
Organic Success PM Straightneck Summer Squash
A major breakthrough in open-pollinated summer squash. Prolific plants keep cranking right through powdery mildew season, producing smooth, uniform, and attractive fruit. In our 2004 trials, Success out-performed standard hybrids in total yield. Provided over three months of abundant, disease-free, harvest for the Intervale Community Farm CSA in 2008. Our stock seed has been carefully selected for yield and shape. First released by High Mowing Organic Seeds and the Cornell Vegetable Breeding Institute. (Cucurbita pepo)
Seed Planting Depth: 1/2-1 inch
Seed Spacing: 3 seeds/ft
Days to Germination: 7-14
Plant Spacing After Thinning: 12 inches
Plant Height: 24-30 inches
Days to Maturity: 50
Seed Saving Difficulty: Easy
Organic Blacktail Mountain Watermelon
Our best quality melon for short, cool seasons. An icebox favorite similar to Sugar Baby in appearance with a distinct crispness and sweet flavor that rivals modern hybrids. The fruit is solid dark green and has an orange-red flesh. Fruit averages 6-10 lbs and 8” across. Vines reach 10’. Excellent keeping quality and yields. Harvest just before ripe and melons will finish off in storage. Keeps for up to two months. (Citrullus lanatus)
Seed Planting Depth: 1/2 inch
Seed Spacing: 3 seeds/ft
Days to Germination: 5-10
Plant Spacing After Thinning: 12-18 inches
Plant Height: 12-16 inches
Days to Maturity: 76
Seed Saving Difficulty: Easy
Organic Sugar Baby Watermelon
An excellent northern, short-season variety that produces reliable yields of 6-12 lb, perfectly round fruits ranging from 7-8.5” in diameter. Fruits have a solid green rind and deep red flesh. Flavor is sweet and juicy. The standard for small watermelons. Our strain has been selected for cool growing conditions and high yields. Shows good resistance to drought. (Citrullus lanatus)
Seed Planting Depth: 1/2-1 inch
Seed Spacing: 3 seeds/ft
Days to Germination: 3-10
Plant Spacing After Thinning: 12 inches
Plant Height: 12-16 inches
Days to Maturity: 78
Seed Saving Difficulty: Easy
Organic Costata Romanesco Zucchini
HEIRLOOM This Italian zucchini wins every taste test based on its unique, slightly nutty flavor and exceptional texture. Tender, gray-green skin and prominent ribbing also give this Italian variety a distinctive appearance. Great picked at 6" or smaller with the flower still attached and fried whole. (Cucurbita pepo)
Seed Planting Depth: 1/2-1 inch
Seed Spacing: 3 seeds/ft
Days to Germination: 7-14
Plant Spacing After Thinning: 12 inches
Plant Height: 24-30 inches
Days to Maturity: 54
Seed Saving Difficulty: Easy