Squashes: sowing, planting, growing, harvesting

Description and Botany

All squashes of the genus Cucurbita are native to America, while those of the genus Lagenaria, namely the gourd, are native to Africa. Regarding Cucurbita, all wild forms are bitter, so it is highly likely that the earliest forms of domestication focused on selecting seeds rich in lipids and proteins. The oldest remains of C. pepo date back to 8000 BC in Mexico, and then 5500 BC in the state of Tamaulipas. As for C. moschata, remains date back to 7000 BC also in Mexico and Peru (3000 BC). All the different species thus originate from a large geographical area from South America to Central America.Squashes were introduced to Europe in the 16th ^th century with Christopher Columbus. They were accepted and cultivated very quickly, unlike tomatoes and potatoes!

In etymology, the term “squash” derives from the Latin “Cucurbita“, which also gave rise to the word “gourd”.

There are about fifteen species in the genus Cucurbita, of which four are the most cultivated in our gardens. These include Cucurbita pepo, Cucurbita moschata or musky squashes, Cucurbita maxima, and finally Cucurbita argyrosperma.

Here are some details about the main species:

• The Cucurbita pepo: these are the most represented in gardens, including certain pumpkins, zucchinis, pattypans, etc. They are generally recognized by their rigid, lobed leaves and their angular peduncle with at least 5 ribs that do not widen at the point of attachment to the fruit.
• The Cucurbita moschata or musky squashes: they have soft leaves. The peduncle is very ribbed and visibly widens at the point of attachment to the fruit. The leaves are heart-shaped.
• The Cucurbita maxima: these are mainly the potimarrons, pumpkins, and giraumons. Their peduncle is rounded and has a somewhat spongy appearance. As the name of the species suggests, it mainly concerns varieties with large fruits. The leaves have 5 lobes.
• The Cucurbita argyrosperma: very rarely found in our gardens, they show trilobed leaves and a very thick, robust, and non-ribbed peduncle.

Currently, there are several hundred varieties of squashes cultivated around the world.

Squashes belong to the large family of Cucurbitaceae, they are generally sprawling, with their long stems they can crawl several meters on the ground or cling to any support using their tendrils.

The flowers are relatively large, yellow, and campanulate in shape. They are monoecious plants, meaning they bear both male and female flowers on the same individual. Female flowers are distinguished from male flowers by their inferior ovary located beneath the flower, which is the unformed fruit. Male flowers do not have this ovary; they are borne on a long peduncle.

Allogamous, squashes favour cross fertilization. On the same plant, male flowers appear first, and once faded, it is the turn of the female flowers to open. This cycle repeats several times during the season. Through this strategy, squashes thus promote fertilization from other plants of the same species. They are also entomophilous, meaning they use insects as pollination vectors. The flowers open only once for about 3 hours, a relatively short time for fertilization!

The fruit is a berry, also called “pepo” by botanists. A great diversity of shape, colour, and size can be appreciated, depending on the species and varieties.

Squash seeds – Male flower – Female flower – A young butternut and a potimarron

Squash varieties

Here is my non-exhaustive selection of varieties chosen for their taste quality, originality, and good success in the vegetable garden. Feel free to check out our wide range in the shop to discover more!

Squash Waltham Butternut - Cucurbita moschata

Butternut Waltham is a variety that produces fruits weighing 1.5 to 2 kg at ripeness, with orange flesh. The taste of Butternut Waltham is sweet and fragrant, of excellent quality. It has good storage qualities.

• Flowering time August, September
• Height at maturity 45 cm

See the product sheet

Kabocha Squash Red Kuri - Ferme de Sainte Marthe seeds

Uchiki Kuri squash, also known as Red Kury, is a variety of Japanese origin, it is THE reliable choice for squashes! It produces fruits weighing about 1.2 kg with orange skin and orange-red flesh, indicating its high carotene content. Its flesh is dense and offers a delicious chestnut flavour. This variety stores well for several months. In the garden, it is productive, yielding about 5 fruits per plant.

• Flowering time July to October
• Height at maturity 30 cm

See the product sheet

Pumpkin Atlantic Giant - Giant Squash - Cucurbita maxima

Atlantic Giant pumpkin, also known as Gargantua squash, is a variety that will be grown more for its impressive size than for its taste! It holds the world record, over 700 kg! But beware, these finest specimens are very particular selections, with each seed selling for several hundred dollars. When well cultivated, it will still reach 150 to 250 kg!

• Flowering time July to October
• Height at maturity 60 cm

See the product sheet

Squash Longue de Nice - Vilmorin Seeds

Nice long-fruited squash is not a variety of courgette but can be consumed like a courgette, that is to say before its ripeness. This squash produces long fruits that can reach up to 1 m in length with a diameter of 18 cm at ripeness! The orange flesh is firm, with a musky and slightly sweet flavour.

• Flowering time June to August
• Height at maturity 40 cm

See the product sheet

Cucurbito pepo Lady Godiva organic seeds - Pumpkin

Lady Godiva squash is a variety that is primarily grown for its seeds. These are shell-less and are consumed dried, raw, or roasted. Its flesh is of average quality but quite suitable for soup. It is a low-vining variety with average yield, producing 2 to 5 fruits per plant.

• Flowering time June to August
• Height at maturity 50 cm

See the product sheet

Squash Black Futsu - Ferme de Sainte Marthe Seeds

Futsu Black Rinded Moschata squash is a variety of musky squash of Japanese origin that produces small round fruits (up to 1 kg) with strong ribbing, featuring a beautiful copper-orange colour at ripeness. Its flesh is yellow, sweet, and fragrant. With good productivity, a plant can yield up to 10 fruits under good growing conditions.

• Flowering time July to September
• Height at maturity 45 cm

See the product sheet

Winter Squash Muscade - Musquée de Provence

Provence musky squash is a variety that produces large plump fruits weighing 8 to 20 kg, ribbed, with a glazed terracotta colour. Its bright orange flesh is sweet with a musky flavour, of excellent quality. In cultivation, it is a very vining variety that yields 2 to 5 squashes per plant.

• Flowering time July to October
• Height at maturity 40 cm

See the product sheet

White Pattypan Squash - Cucurbita pepo

White Patisson is a beautiful old variety shaped like a star or UFO, which earns it the name UFO in Northern Europe. Its cream-white fruits produce flesh with an artichoke-like flavour, reaching up to 3 kg and 25 to 30 cm in diameter. It is a non-vining variety, consumed young like courgettes or mature like squashes.

• Flowering time May to July
• Height at maturity 60 cm

See the product sheet

Spaghetti Squash - Cucurbita pepo

Spaghetti squash gets its name from the texture of its very fibrous flesh after cooking, resembling spaghetti, and has a mild flavour. The fruits weigh between 2 to 4 kg and are orange-yellow at ripeness. This low-vining variety produces plants that will yield 2 to 5 fruits.

• Flowering time June to August
• Height at maturity 45 cm

See the product sheet

Squash Buttercup Burgess

Butternut Burgess pumpkin is an old, vining variety that produces turban-shaped fruits measuring 13 to 20 cm in diameter, weighing 1.5 to 2 kg, with dark orange, fine, and sweet flesh, whose flavour is similar to that of sweet potato. Many gardeners consider Buttercup to be among the most delicious squash varieties!

• Flowering time June to August
• Height at maturity 50 cm

See the product sheet

Sow the squashes

Where and when to sow squashes?

Sowing squashes is easy to do, it can be done in buckets or directly in the ground.

Squashes are sown:

• from mid-April to mid-May in a warm environment, indoors or in a heated shelter,
• from mid-May to mid-July directly in the ground.

How to sow squashes?

You can prepare young plants to be planted in the vegetable garden once all risk of frost has passed or sow directly in place.

• Preparing young plants:

1. Fill buckets with seed compost
2. Place two seeds per pot (flat) pushing them down to a depth of about 2 cm and cover with compost,
3. Water for the first time, using light rain or by capillarity by filling the saucer with water and allowing the water to rise for at least a quarter of an hour, then remove the excess water.

Keep warm and in the light, at around 20 °C and maintain the substrate moist but not waterlogged until germination, which generally takes between 5 and 8 days. When the young plants are well developed, thin them out by keeping only the strongest seedling.

• Sowing directly in the ground (after mid-May):

Sowing is done in clusters, in weeded and loosened soil, spacing the plants one metre apart in all directions:

1. Dig holes 2 to 3 cm deep,
2. Place three seeds per hole and cover with fine soil and lightly compact,
3. Water for the first time, using light rain to avoid displacing the seeds,
4. Keep the soil moist until germination.

After germination, when the young plants are well developed, thin them out to keep only the best plant from each cluster.

→ Learn to succeed in sowing loofah squashes or vegetable sponges in our tutorial

Sowing squash seeds in buckets

Planting squashes

When to plant squashes?

Planting of squashes takes place from May, preferably after the Ice Saints, in the regions most sensitive to cold. In the South and along the coast, they can be planted as early as mid-April, monitoring the weather and possibly protecting them from the last frosts with a cover. It is possible to continue planting until July.

The planting distances are 1 to 2 m between each young plant, refer to the seed packets.

How to plant squashes?

Squashes require a well-manured soil, previously enriched with an addition of compost or well-rotted manure of 3 to 4 kg per m². This is a bulky crop for which a minimum area of one square metre per young plant should be reserved.

To plant your squashes:

1. Dig a hole corresponding to the volume of the root ball,
2. Place the root ball and cover it with soil,
3. Firm the soil and water to keep it moist,
4. To aid recovery, water at the base regularly.

Cultivation, care and associations

All squashes should be grown in sunny locations, as they are greedy vegetables that thrive in rich, organic, loose, deep, and cool soil. Indeed, squashes particularly enjoy slightly moist soils, so remember to mulch around the plants, especially during the height of summer. It is also advisable to add a generous amount of compost, around 3 to 4 kg per m², before planting.

For maintenance, it is important to hoe and cultivate, especially at the beginning of the growing season; afterwards, the dense foliage of the squashes limits the growth of “weeds”. When the fruits develop, it is useful to place a slate or tile under the fruits, preventing them from coming into direct contact with the soil, thus avoiding rot due to moisture.

The squash is part of the most famous of vegetable associations, the milpa, also known as the three sisters association. These three plants provide mutual benefits: nitrogen residue from the bean (after harvesting), the corn serves as a support for the bean, and the squash protects the soil with its imposing foliage, providing more coolness, creating a microclimate, and competing with adventive plants. To learn more about the milpa, check out our article on corn.

Squash enjoys the presence of Liliaceae such as chives, onions, or shallots, as well as Fabaceae like beans and peas. However, the squash-cucumber pairing may be detrimental to both parties.

Squash associated with corn – Squashes and flowers, a good association as well![/caption>

→ Learn more about harvesting and storing squashes in our tutorial!

Common diseases

Generally, squashes experience few pests and diseases; they are quite robust plants. However, attention should be paid to powdery mildew, which can harm the crop, especially if it appears early in the season.

Powdery mildew of squashes

Powdery mildew is a cryptogamic disease (caused by a fungus) that manifests as white, powdery spots on the leaves. These eventually dry out, yield decreases, and the plant may ultimately die. This disease appears when conditions are warm and humid. Consult Virginie’s article to prevent and combat powdery mildew in Cucurbitaceae.

→ Read also: Diseases and pests of squashes and courgettes

Harvest and Preservation

Squashes are harvested at ripeness when the peduncle becomes dry and woody, which is retained on the fruit. The harvest is done before the first autumn frosts to avoid damaging the fruits. Squashes should be handled with care and remain free from any cuts or bruises. They are ideally brushed under a stream of water to remove any traces of soil, then dried, which helps improve their shelf life.

Squashes can thus be stored for several months and consumed throughout winter. Unlike other fruits and vegetables, they tolerate room temperature very well, although the optimal storage temperature is around 15°C. There is no need to store them in a dark place, so it’s best to keep them where their aesthetic shape can be appreciated. Once stored, check from time to time that the squashes are not rotting; if so, quickly remove the affected squash before it contaminates the others.

→ Discover Ingrid’s tips on lacto-fermentation conversation.

Uses and nutritional benefits

There are many ways to consume squashes: sautéed, fried, in gratins, in soups or velvety dishes, stuffed, in jams, as vegetable spaghetti for Spaghetti squash, and roasted seeds for Lady Godiva; Halloween soup is, of course, served in the hollowed-out vegetable! In short, there is no shortage of recipes! To easily peel your squashes, a very simple and effective technique is to start cooking them in the oven at a high temperature. The squash is placed whole, the skin will harden and blacken in places, and the flesh will take on a slightly smoky flavour, which is very pleasant for enhancing the taste of certain dishes!

Squashes are low in calories (carbohydrates and fats) and contain few proteins and fibres, making them an excellent weight-loss vegetable! However, they are rich in provitamin A, which helps maintain beautiful skin, normal vision, proper iron metabolism, and the proper functioning of the immune system. Squash is also a source of vitamins B6, B5, and E, as well as minerals, and is particularly rich in selenium, which contributes to the maintenance of hair and nails, thyroid function, the immune system, and cellular oxidative stress, which is also good for men by maintaining normal spermatogenesis. Pumpkins and other sweet pumpkins, with their bright orange colour, are rich in carotenoids; they are indeed the vegetables best endowed with this antioxidant molecule!

→ Discover How to make pumpkin butter in our tutorial!