Gardening Hybridizing Pollination Vegetables

Saving Squash Seed: No Hanky Panky Allowed!

A zucchini pumpkin hybrid. Long, oval, green outside, yellow inside.e

Par Larry Hodgson

Squashes are masters at crossing with their neighbors. Even varieties that are very different in appearance, such as zucchini, pumpkin, patty pan and vegetable spaghetti are all derived from the same species (Cucurbita pepo) and will cross readily. The fruits that result from crossed seed will be hybrids (mongrels), therefore likely intermediate in appearance, taste, and texture between the two parents, and not usually what you want.

(Do note that such illicit crosses don’t affect the current season’s fruits. A spaghetti squash plant will always produce spaghetti squashes, even if its flowers are pollinated by a patty pan or a zucchini. It’s the second generation, that is, plants grown from the seeds of a crossed flower, where genes get mixed up!)

If you intend to harvest squash seeds for next year’s sowing, it’s therefore best to limit yourself to growing only one variety in your entire vegetable garden. In community gardens, where a wide variety of squashes are sown, it’s probably best not to save seeds.

Commercial growers of squash seed leave a mile (about 1.5 km) between plants to ensure varietal purity. Even then, it sometimes happens that a squash plant you grew from seed produces fruit that looks nothing like those in the seed pack’s picture. If so, just blame an errant bee!

Can Squash Cross With Cucumbers?

Cucumbers and squash sometimes look a lot alike and are indeed distant relatives, but they won’t cross. Photo: Max Pixel

No, there is no risk that a squash will cross with a cucumber, nor with a melon, despite what you sometimes read on Facebook. It is true that these three vegetables are related (they belong to the Cucurbitaceae family), but they’re distant relatives, no more closely related than, say, a house cat and a tiger, and no cross is possible. I mean, how many catigers wander your neighborhood?

On the other hand, if you want to save cucumber seeds and ensure the purity of the line, you should also limit yourself to one variety per garden. And the same goes for melons: you also have to stick to growing one variety in isolation if your goal is to save the seeds.

Text based on an article originally published in this blog on September 4, 2016. 

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

7 comments on “Saving Squash Seed: No Hanky Panky Allowed!

  1. True but if you have the space or are just curious it can be a lot of fun to see what the second generation produces.

  2. Plant Squash Weeks Apart
    It’s also possible to isolate squash varieties by time. By creating a gap between each plant’s flowering period, you’re sure to reduce their chances of cross-pollinating. While this can be difficult to do in regions with relatively short growing seasons, it’s a good option for anyone who isn’t keen on bagging or hand pollinating their plants.
    Nicole Garner Meeker
    https://davesgarden.com/guides/articles/5-tips-for-avoiding-squash-cross-pollination

    • Excellent idea. Of course, it wouldn’t work in my 85-day growing season!

      • Sorry, but you have the ear of gardener all over North America, so maybe some of them could use the gap planting.

      • I’m not complaining. Far from it. Your information is very helpful. Please feel free to suggestions or additions when you see something that deserves it!

  3. My squash do not hybridize, supposedly because they are different species. (I did not plan it that way.) I know others get surprises in their gardens though.

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