Gardening Hybridizing Pollination Vegetables

Saving Squash Seed: No Hanky Panky Allowed!

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. 

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

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

  1. 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.

  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

    • 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. 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.

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