Squash, courgettes, melons: what are the risks of hybridisation and is it dangerous?

It has to be said: we love our brightly-coloured winter vegetables, such as pumpkins, squash and gourds, which we love in gratins or soups. They all belong to the cucurbit family. But this family also includes courgettes, melons and cucumbers. If you plant any in your garden, you may run the risk of hybridisation. So how does it work?

A question of pollination

Some Cucurbitaceae are capable of self-pollination, but there are risks of cross-pollination thanks to our pollinating insects. If your vegetable plants are not far apart in your kitchen garden, you are likely to encounter this type of pollination then the seeds that will be produced by the vegetables from that plant will carry the genes of both species. So if you sow these seeds the following year, you'll have hybrid vegetables. As you can see, hybridisation only occurs if you harvest the seeds of two related varieties and replant them the following year!

Squash + melon = courgemelon? :)

Even though squash and melons belong to the same family, the Cucurbitaceae, this does not mean that they will be able to hybridise. In fact, the vegetables have to belong to the same species for this risk to arise. For example, courgette and spaghetti squash belong to the same species, Curcubita pepo, so they will be able to hybridise. The same goes for Halloween squash, which could make babies with your courgettes! However, neither of these two species will be able to hybridise with butternut squash, which is part of the Curcubita Moschata species.

It all depends on the hybridization that has taken place. If the two hybridised species are edible, then you can eat the hybrid vegetables without any problem, even if the taste can sometimes be... surprising. However, cross-pollination can sometimes lead to hybridisation between an edible and a non-edible vegetable. This is the case with the Curcubita pepo species. This family includes vegetables known as decorative or coloquinte. These vegetables keep for a very long time dried. They can be painted or engraved, but they are not edible. So, if a courgette and a coloquinte hybridize, then the fruit from the hybrid seeds cannot be eaten.

How do you know if the vegetable is safe to eat? Coloquintes are rich in cucurbitacin and can cause intestinal problems if eaten, even if cooked. Fortunately, nature has done things well. Their flesh is very bitter. So if one of your vegetables is very bitter, there's a good chance of cross-pollination.

How to avoid cross-pollination

The only way to avoid any risk of pollination between a coloquinte and a courgette, for example: do it manually. In fact, manual pollination simply involves transforming yourself into a bee and manually pollinating the male and female plants. The female flower is easily recognised by the swelling at its base. You can, then, cut off the stamens of the male flowers.