Courgettes cultivation

How to grow zucchini

Characteristics of Zucchini

Zucchini or courgette (Cucurbita pepo) is a plant of the Cucurbitaceae family, the same family to which pumpkins, melons or watermelons belong.

Zucchini is a plant native to America, which was arrived in Europe at the beginning of the sixteenth century.

What is zucchini like?

Creeping annual plant, up to 10 meters long.

Stem cylindrical and rough to the touch, divided into internodes.

Leaves petiolate, large, webbed, with five lobes, green and with harsh villi in the lower part of the limbus. Toothed margins.

Zucchini flowers are large, pedunculated, bright yellow and flared.

Fruit fleshy, elongated, cylindrical and, in general, dark green or clear.

In general, the fruit is harvested before ripening, when it is considered that the texture and the organoleptic qualities are more pleasant; and when their seeds have not yet been formed.

Varieties of zucchini

Within the same species, different varieties or types of zucchini may exist. These might be:

• Zucchini elongated and large in size: usually dark green, light green, yellow or white. These courgettes can be eaten tender, when they are still in flower and measure between 15 and 20 cm .; or when they reach their maturity and maximum size, which are usually consumed.
• Round zucchini
• Flattened zucchini or bonnet, called zucchini of Jerusalem.

Climate and conditions for the cultivation of zucchini

•  Like all cucurbits (pumpkins, melons, watermelons, cucumbers, …), zucchini requires exposure to sunlight.
• Warm or temperate temperatures, between 18º and 25ºC. It supports high temperatures.
• Sensitive to cold, temperatures below 8ºC can damage the plant and even stop its development.
• Sensitive humidity and very rainy climates.

Soil conditions for zucchini

– Frank soils rich in organic matter.

– Good soil drainage to avoid puddles.

– The soil pH between 5.5 and 5.9, but tolerate up to 6.8.

– Moderately resists salinity.

– It does not tolerate alkaline soils, in which it can develop symptoms of nutrient deficiency.

Fertilization of zucchini

– Zucchini is a crop that requires soils rich in organic matter.

– Compost with manure or compost.

Irrigation of zucchini

– Zucchini is a horticultural crop with clear demands for periodic irrigation, especially in the growing season of the fruit.

– It is important that no puddles are formed, and not over watering, as it may favor the appearance of diseases, rot or suffocation of the roots and consequent death of the plant.

– On the other hand, a lack of irrigation will cause damage to the plant, such as falling flowers, small fruits or dehydration.

– A drip irrigation system is recommended. An alternative is to make small holes in a hose, and activate the water at low power.

– Sensitive to excess soil moisture.

Propagation of zucchini

Zucchini is propagated by seeds. The following steps can be followed:

• Preparation of the ground: the zucchini is a plant that produces a large amount of fruit. For this reason, it is important to provide a fertile soil rich in nutrients that promotes fruiting.
• One month before sowing, it is recommended to make a hole for each plant, approximately 25cm. of diameter and depth, and fill with 35kg. of compost. We will add soil, mix, compact the soil lightly. Another type of alternative fertilizer consists of green fertilizer rich in potassium, such as comfrey leaves.
• Zucchini plantation: the seeds are planted in a protected nursery or in the land field that we have prepared, depending on the weather. Zucchini can be planted in late winter or early spring, between February or May. The sowing of zucchini takes place on the days of full moon or ascending moon.
• Maintain a separation of 90-100cm. between plants.
• Sowing can be done by furrows, terraces, eras and even in flowerpots.
• So late as June and July are no longer suitable months for sowing, since the humidity of autumn and the cold of winter will slow down the growth of the fruits. In those cases, it must be done in a greenhouse.
• Periodic irrigation, especially during the fructification of the plant, avoiding puddles.
• It is important to control the possible animals that hide among the foliage and feed on the plant, especially during the first months of growth, such as snails or slugs.

How to collect zucchini

Collection time may vary depending on the variety and climate. Generally, it is done when the fruits have not yet fully matured, approximately 50 days after sowing. With a knife, cut the fruit with the peduncle (to prevent diseases and rot), approximately 2-3cm.

If we pick the very immature courgettes (at least, larger than 15-20 cm.), we will stimulate the fruit production. Zucchini plant can provide fruits every week. Regular or weekly harvest, stimulates the growth of the other fruits of the plant.

Precautions: the skin of the zucchini is very soft and sensitive to shock, it tears easily. We must stack them and manipulate them delicately.

In winter, the plant stops producing fruit. The leaves and stems of the plant can be used to fertilize the soil.

Advantages of eating zucchini

Zucchini is a soft vegetable, with high water content, which makes it a low-calorie fruit, ideal for weight loss diets. It is also ideal for people with diabetes, because of its low sugar content.

It hardly contains sodium, so it is suitable in diets for hypertension, when it is not cooked with salt.

It is a moisturizing vegetable, which lubricates the intestines and helps fight constipation.

It is cooked as a vegetable in stews, stews, stuffed (stuffed zucchini), for dumplings, batters, creams and ratatouille.

Zucchini flowers are also consumed, sautéed or stuffed.

* More information of zucchini properties

How to obtain zucchini seeds

Zucchini is a fruit that is consumed immature, when it has not yet formed its seeds. It is even consumed when it measures just over 10cm. and it’s still in bloom. In our garden, we will try to select one or more of the most vigorous plants, a pair of courgettes to ripen and produce seeds. The seeds will serve us for the next harvest.

Cultivation tasks

• Thining: when more than one plant is born, a thinning is done to remove the weakest and leave the most vigorous. It is done when the plant has the first 3 true leaves.
• Deleafing: the damaged or yellowed leaves have to be removed to increase the solar exposure of the plant and facilitate aeration. It is done to encourage greater growth and prevent diseases.
• Pinching: the terminal part of the stem should be cut to favor the growth of the secondary branches.
• Pruning: Deformed or damaged fruits are harvested to promote the growth of other healthy courgettes.

Diseases and pests of zucchini

The main pests and diseases that affect zucchini are:

• Aphids (Aphis gossypii): can appear in wet seasons, in spring or autumn. They are distinguished because they are recognizable to the naked eye.
• Red spider mite (Tetranychus urticae): characterized because it produces discoloration on the underside of the leaves, yellow spots or desiccation. Red spiders suck the sap and weaken the plant. If you look at the underside of the leaves, you can see small red dots. It occurs when the weather is dry and temperatures are very high.
• Silver leaf white-fly (Bemisia tabaci): type of pest produced by a whitefly. It lays its eggs on the underside of the leaves. Both the larvae and the adult specimens feed on the plant, which leads to leaves yellowing . It can be prevented by wetting underside of the leaves of this plant with potassium soap or even with a little clay. If the pest is already existing, use specialized insecticides, preferably ecological.
• Powdery mildew (Sphaerotheca spp.): Disease caused by fungi very common in crops of cucurbitaceous plants. It happens when irrigation is too abundant, or when the soil is very rich in nitrogen. Characterized by white spots on the leaves. There are preventive remedies easy to acquire in specialized gardening stores.
• Zucchini yellow mosaic virus (ZYMV): yellow spots with embossed leaves, leaf necrosis (limb and petiole), less growth of the plant and possible deformations.

Crops associated with zucchini

Horticultural crops can be associated with other plants, with specific characteristics that improve soil nutrients, and benefit plant growth. Zucchini can be associated with:

• Lettuce cultivation: edible association
• Cultivation of beans: edible association
• Corn cultivation: edible association
• Cultivation of cabbage: edible association
• Nasturtium: edible association (leaves) and also used to control pests.
• Mint cultivation: cultivation of aromatic plant.
• Radishes cultivation:edible association

It is NOT recommended to associate zucchini potatoes.

* Related information:

Medicinal properties of pumpkins

Characteristics of pumpkins

Properties/ Pumpkin classes

Pumpkin flowers / Pumpkin seeds

More information on courgettes and pumpkins.

Written by Editorial Botanical-online team in charge of content writing

5 July, 2024