Growing Cucumbers, Melons and Squash

One of the most frequently asked questions I get is “Can I plant cucumbers, melons and squash together?” The answer is an absolute yes, and no.

Here’s why. These are all members of the Cucurbit family, and as such they suffer from the same pests and diseases. If you have a large garden, you may want to hedge your bets and make two separate plantings, in the hopes that at least one will not get attacked. On the other hand, if space is a premium, plant them together so you can rotate all three the following season.

Then there’s the cross-pollination thing, which there seems to be much confusion about, and is usually the worry behind the question. Unless you intend to save seeds, cross-pollination is irrelevant because it only affects the plants that grow in the next generation. A pumpkin and a zucchini are not going to produce a ‘pumpini’ in your garden, at least not the first year. If you want to save seeds from open-pollinated or heirloom plants, rest assured that cucumbers, squash and melons cannot cross-pollinate with one another. However, one squash can breed with another of the same species; likewise melons with melons, and cucumbers with cucumbers.

The key term here is species. Here’s an example, let’s say we take four kinds of winter squash: Kikuza, Red Kuir, Spaghetti, and Butternut. Who can cross with whom? Just look at their botanical names, Cucurbita moschata, Cucurbita maxima, Cucurbita pepo and Cucurbita moschata, respectively. The second part of the botanical name is the species, which tells us that the Kikuza and Butternut can cross-pollinate. Throw in some zucchini or pumpkin seeds, which are most often Cucurbita pepo too; now your spaghetti squash are at risk. Their seeds may not reproduce true to the parent. Cucumbers are Cucumis sativus and most melons Cucumis melo, so they cannot cross-pollinate.

So here’s the deal. If you’re not saving seeds, plant whatever you want, even from the same species. If you intend to keep the seeds from heirloom and open-pollinated veggies, either plant only one variety of each species or keep them very far apart.

Here in the Jones garden we like to plant 'Kikuza', 'Red Kuir' and 'Dishpan Cushaw' squashes this year, as well as the seeds we save from 'Banana' melon, 'Lemon' cucumber and 'Moon and Stars' watermelon.

All heirlooms or open-pollinated, all unrelated, and all to provide us with plenty of seeds, no matter what we plant them near.