By Jill Henderson – Show Me Oz -
With Thanksgiving just around the corner, the last thing people might be thinking of is gardening, but the two go together like pumpkin pie and whipped cream. In fact, if you grew your own pumpkins or squash this year and plan on using the sweet flesh to make delectable holiday treats, now is the perfect time for saving their seeds. Extracting and drying seeds from hard-shelled squash and pumpkins is fairly straightforward, however, you must first be sure that the seeds you save now will come true to type next year.
Although squash and pumpkins are often seen as separate vegetables, both are winter squashes belonging to the Cucurbitaceae Family. Other garden relatives include gourds, summer squash, cucumbers and melons. Unlike their summer cousins, winter squash have relatively dry, sweet flesh. They are picked after their outer shells have hardened and the flesh fully ripened. The hard outer shell protects the flesh within, allowing winter squash to be stored for long periods of time, which is one reason winter squash is a natural favorite for holiday dishes.
Every plant in the world is classified through a system of nomenclature, which allows us to see how they are, or are not, related. Just like us, all plants belong to a family. Their names can span many generations and include ancestral relationships. Plants are classified in descending order from Kingdom through Variety. For basic seed saving purposes, we need only focus on those names that represent the Family, Genus, Species and Variety. For example:
Hubbard Squash (Cucurbita maxima var. Hubbard) is broken down this way:
Family – Cucurbitaceae
Genus – Cucurbita
Species – maxima
Variety (or named cultivar) – Hubbard
The more names a plant shares with another plant, the closer they are related. If two plants do not share the same species name, they cannot pollinate one another at all. If they do share the same species name, they will almost always have the potential to pollinate one another. If those same two plants also share the same variety name they have the ability to produce seeds that will bear exact duplicates of one another (i.e. a pure strain) when pollinated by one another.
Cucurbits are a large and diverse family of plants that have a tendency to cross-pollinate. If you save seed that was crossed with a different variety within the same species, the plant that grows from that seed may not be what you expect it to be. For those new to saving seed, allow me to explain in more detail.
Once you know how different plants are related, it is easy to understand how they reproduce, since plants belonging to the same genus use the same process. In the case of Cucurbit species, all have separate male and female flowers on each plant. To complete sexual reproduction, the flowers completely rely on insects to move pollen from the male flower to the female flower. To attract pollinators, Cucurbits often have large, showy flowers with exposed reproductive organs. This method of pollination is very effective, but not necessarily selective. It essentially allows insects to deposit pollen from both related and unrelated species. If the pollen comes from a flower of the same exact species of squash, then the resulting seed will bear the same exact fruit when planted. If not, it’s anyone’s guess what the offspring will look and taste like.
There are four species of Cucurbits that we need to keep an eye on: C. maxima, C. mixta, C. moschata, and C. pepo. In general, you can grow one variety of squash from each of these four species without worrying about cross pollination. The real problem lies in knowing which variety belongs to which species, as that isn’t always obvious. That is why I have included the following list of species and their varieties. Keep in mind that this list is not 100% complete. If in doubt, simply ask the company from which you bought your seed.
Cucurbita maxima varieties include banana, buttercup, Hubbard, Hokkaido, kubocha, sweet keeper, red kuri, delicious, French turban, and marrows. All of these varieties will cross pollinate each other, but not those of other species.
Cucurbita mixta varieties include all cushaws, many green-and-white striped squash, Japanese pie, silverseed gourd and Tennessee sweet potato. All of these varieties will cross pollinate each other, but not those of other species.
Cucurbita moschata varieties include, cheese type squashes and pumpkins, all butternuts, and winter crooknecks. All of these varieties will cross pollinate each other, but not those of other species.
Cucurbita pepo varieties include many types of gourds, winter squashes such as acorn, delicata, cocozelle, English marrow, most types of sweet pumpkins and all summer squashes including yellow, crookneck, scallop, spaghetti and zucchini. All of these varieties will cross pollinate each other, but not those of other species.
There are conflicting reports of cross breeding within the different species of the genera, but for the home seed saver, the best method of ensuring purity is to grow only one variety of each of the four species during the growing season. Otherwise, isolate varieties within the same species by up to a mile or hand-pollinate individual flowers.
As previously mentioned, harvesting seeds of winter squash are pretty straightforward. Simply cut open the fruit and scoop out the seeds into a large bowl or bucket. Add a generous amount of water and rub the seeds away from the fleshy membranes. Pour off any floating seeds and chaff, repeating as necessary until the water contains only ripe seeds, which sink in water. Drain the seeds well and dry on a rigid surface such as a ceramic plate (never paper) away from direct sunlight until the seed breaks when folded in half. Store seeds in a dark cool place.
Once you know how to save the seeds of your home-grown winter favorites, you’ll never have to buy another squash seed again. Enjoy!
Whether you’re a weekend gardener, homesteader, or serious survivalist, saving seeds is a money saving skill that every green-thumb should to have. An excellent resource for beginners and experienced gardeners alike, The Garden Seed Saving Guide takes you step-by-step through every aspect of saving seeds. If you want to save money, become more self-sufficient and avoid genetically modified food crops, The Garden Seed Saving Guide is for you. Available in the Show Me Oz Bookstore
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Jill Henderson is an artist, author, and the editor of Show Me Oz . Her books, The Healing Power of Kitchen Herbs, The Garden Seed Saving Guide and A Journey of Seasons can be found in the Show Me Oz Bookstore. Jill’s work has also appeared in The Permaculture Activist, The Essential Herbal, Acres USA, and Llewellyn’s Herbal Almanac.