Common Questions About… Zucchini!

You often have questions about zucchini. So let’s go for a general review of this prolific vegetable.

What Is a Zucchini?

First of all, zucchini is a summer squash (Cucurbita pepo), i.e. a squash that is eaten immature, in midsummer, before its rind thickens and hardens. It’s often called “zucchini” after its Italian name. There are many other types of summer squash, of which the pattypan is perhaps the best known. Winter squash, such as pumpkin, spaghetti squash, turban squash, butternut, etc., are related, but are best eaten in autumn, when their bark is well formed.

Zucchini is a “non-runner”, meaning it has a short stem almost entirely covered in leaves, and occupies a more limited space in the garden (around 40 cm, 18 inches) than most other runners, whose creeping stems run in all directions.

Zucchini prefers full sun, or almost full sun, and rich soil, especially compost. It is totally intolerant of frost, so don’t sow it too early. It is usually sown in early June, when the soil has warmed up. You can also leave it in peat pots in the house, 3 weeks before the planned transplanting date. It’s important to always rotate crops, as zucchini is highly susceptible to insects and diseases that overwinter in the soil where it (or any other Cucurbitaceae, such as melons and cucumbers) grew the previous year.

Why Won’t My Zucchini Flower?

This happens especially when the plant lacks sunlight or the soil is constantly soggy.

Why Don’t I Have Any Fruit?

This requires a rather extensive explanation. You see, in the plant kingdom, the majority of flowers bear both sexes, but this is not the case with squash. In squash, every plant bears flowers of both sexes, but the flowers are either male or female. These are easily distinguished, as the female flower already bears an ovary, in the shape of the future fruit, at its base. At its center is a stigma, a brain-like structure that’s slightly sticky to the touch. The male flower has no ovary at its base: it is attached directly to the peduncle, which bears a stamen covered with yellow pollen at its center. If you touch it, the pollen sticks to your finger. There are many more male than female flowers.

Obviously, to produce fruit, pollen must be transported from the stamen of the male flower to the stigma of the female flower. Pollen can come from a male flower on the same plant, or from the flower of another zucchini. Normally, bees take care of this job, but if they’re absent from your neighborhood (or if it’s raining, as bees fly little or not at all on a rainy day), you can perform the beework yourself. Cut off a male flower, remove the petals to better see what you’re doing, and stick its pollen-covered stamen to the stigma of a female flower, which will leave a little pollen and thus ensure fertilization. You need to keep an eye on your plant every day, as the flower, male or female, only lasts a day.

Why Do My Zucchinis Form but Fall Off So Quickly?

They have probably not been pollinated. On grey or rainy days, pollinate the female flowers yourself.

Why Are My Zucchinis Gigantic?

Zucchini should be harvested young, when they are no more than 20 cm (8 inches) long, when the rind is thin and the seeds are just small dots with no consistency. If they are left to ripen any longer, the flesh becomes mushy, the seeds develop (and must be removed before serving), and the rind hardens and becomes inedible. What’s more, if you get into the habit of going around your zucchinis and picking the fruit every 2 or 3 days, this constant harvesting stimulates the plant to produce even more fruit. When zucchini are left to ripen, the plant stops producing.

Est-ce vrai que les fleurs de courgette sont comestibles?

Yes, and they can be harvested without affecting zucchini production. This is because there are many more male flowers than female, and the male flowers become useless once fertilization has taken place. So you can harvest them without damaging the crop. Traditionally, they are stuffed or served in tempura by dipping them in a batter.

Why Are My Plants Covered in White Powder?

Your plant is suffering from powdery mildew. This is a common disease in zucchini, but rarely very harmful, as it occurs at the end of the season when the harvest is almost complete. Crop rotation and selection of a zucchini variety resistant to the disease can reduce its scope.

And that’s all there is to zucchini growing in a few paragraphs! You’ll see that, despite its small preferences, zucchini isn’t difficult to grow and is even one of the most productive vegetables in the garden.

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Larry Hodgson published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings accessible to the public. This text was originally published in Le Soleil on August 6, 2006.