Pumpkin: planting, sowing, cultivation

Description and Botany

The Pumpkin (Cucurbita maxima) is an annual vegetable plant from the large family of Cucurbitaceae, which includes melons, cucumbers, and watermelons. Native to South America, from Argentina to Uruguay, passing through Bolivia and Chile, it was introduced to Europe around the 16th century, like all other species of squash. It is cultivated for its large fruits, which vary in appearance due to numerous hybridizations. They differ in shape (spherical, elongated, bumpy, pear-shaped, or “Turkish hat” …), weight (from less than 1 kg to over 200 kg), colour at ripeness (orange, green, red, yellow, black, white, or even grey-blue), and the texture of their epidermis (smooth, ribbed, verrucate, warty…).

The genus comprises about thirty species. The term “pumpkin” is a generic term that encompasses all cultivated varieties of the genus Cucurbita maxima. In common language, winter squash refers to all types of pumpkins, potimarrons, and so on, with tough skin and delicately sweet flesh. Summer squashes refer to courgettes and various varieties that are harvested while still young when the skin is still tender. The pumpkin is often confused with the squash, which is a round, orange squash but belongs to a different species: Cucurbita pepo.

Pumpkin, botanical plate (1822)

Within the family of Cucurbita maxima, we mainly distinguish varieties with large fruits, as suggested by the species name:

• Traditional pumpkins of spherical shape, more or less flattened
• Hubbard pumpkins of oval shape
• Giraumon pumpkins in the shape of a Turkish hat or “monkey bottom”, producing fruits shaped like a hemispherical cap, whole or divided into three or six lobes topped with a more or less coiled turban
• Potimarrons produce smaller fruits, weighing 2 to 5 kg, pear-shaped or spinning top-shaped, with a reddish-orange colour and such thin and tender skin that they do not need to be peeled

The pumpkin is a herbaceous plant known as “running”, meaning it produces long creeping stems on the ground that can reach up to 10 metres in length. They can also climb by attaching themselves to any support using their tendrils. They are equipped with large green leaves, entire, borne on long petioles. They measure 6 to 20 cm long and up to 30 cm wide, are heart-shaped, and divided into five rounded lobes. Their lamina is finely dentate.

Pumpkin ‘Rouge Vif d’Etampes’, pumpkin ‘Galeux d’Eysines’, Pumpkin ‘Bleu de Hongrie'[/caption>

Flowers emerge at the axil of the leaves. They are relatively large, measuring 8 to 10 cm, yellow to orange, and campanulate in shape. They contain prominent stamens. The pumpkin, like all squashes, is a monoecious plant, meaning it bears both male and female flowers on the same plant. Male flowers appear first, and once they have faded, female flowers bloom. Female flowers can be distinguished from male flowers by their ovary, a small yellow pumpkin located beneath the calyx.

Female flowers bear the fruits, while male flowers produce the pollen.

The fruit of Cucurbita maxima is a berry that ripens in autumn. One can appreciate the astonishing variability in shapes, colours, and sizes, from the large ribbed bright orange fruit, like ‘Rouge vif d’Étampes’ and the ‘Jack O’Lantern’ pumpkins with oblong shapes, pear-shaped or “Turkish hat” forms of Giraumon pumpkins ‘Turban’, not to mention the curious ‘Galeux d’Eysines’ pumpkins adorned with corky galls. The skin of some varieties is sometimes variegated with red, yellow, green, and white.

The fruit is attached to the stem by a large round and spongy peduncle. Each plant produces 1 to 5 large fruits. The flesh is firm, fine or thick, dark yellow to light orange, sometimes green, sweet, and tasty. It contains white or yellowish seeds, oval, slightly bulging, measuring 2 to 2.5 cm long.

Main varieties

The variety selection is vast and original. Check out our wide range in-store to discover more!

Pumpkin Atlantic Giant - Giant Squash - Cucurbita maxima

This is a competition beast! This giant pumpkin variety holds the record for the largest squash in the world! Its very thick, light orange flesh is of medium quality but suitable for soups.

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

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Halloween Pumpkin Jack O'Lantern - Cucurbita pepo

This pumpkin is traditionally used to make Halloween lanterns but is perfect for soup! It is a trailing, early, and productive variety.

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

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Pumpkin Rouge Vif d'Etampes - Cucurbita maxima

A vigorous and early variety. Its flesh is thick, yellow-orange, tender, and watery. The yield of this pumpkin is 1 to 4 fruits per plant (30 to 50 cm, 8 to 10 kg).

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

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Pumpkin Jaune Gros de Paris (untreated) - Ferme de Sainte Marthe seeds - Cucurbita maxima

A vigorous variety that produces large yellow-skinned fruits. This pumpkin has good taste quality.

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

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Squash Blue Kuri - Ferme de Sainte Marthe Seeds

A variety with a lovely bluish skin that produces medium-sized fruits with thick, fragrant flesh that has a pleasant chestnut flavour. Delicious in soup!

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

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Pumpkin Hungarian Blue - Ferme de Sainte Marthe Seeds

A variety distinguished by the beautiful bluish colour of its skin. It is grown for its sweet orange flesh. Its fruits store very well.

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

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Pumpkin Galeux d'Eysines - Cucurbita maxima

Beneath its ugly scabby skin, this variety contains fine, firm, tender, and sweet flesh. Original and delicious!

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

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Turban Squash Giraumon - Cucurbita maxima

As good as it is decorative with its variegated colour! This is a very old variety with very firm, sweet, and floury flesh.

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

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Red Kabocha Squash - Uchiki Kuri

A superb, productive variety that matures early. The flesh is thick and offers a delicious chestnut flavour. Excellent storage.

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

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Squash Large Blue Hubbard - Cucurbita maxima

Its hard, bumpy skin contains soft, mildly sweet flesh. To be consumed as fries, gratin, soup, or purée.

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

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Sowing pumpkin

Count approximately 6 months between sowing and harvest.

When and how to sow?

Sowing under cover

Sowing can be done in pots indoors from March, with transplanting after all risk of frost has passed.

• Sow 2 or 3 pumpkin seeds per pot filled with potting soil and compost at a depth of about 2 cm and cover with soil,
• Water lightly
• Keep warm and in light, at a temperature of about 16-30 °C
• Maintain the substrate moist but not waterlogged until germination, which usually takes between 3 and 5 days
• Thin out to keep only the strongest seedlings
• When they have 3 or 4 leaves, transplant the plants outdoors after mid-May, once all risk of frost has passed, in holes 20 to 30 cm deep previously filled with compost or manure
• Water and mulch

Sowing outdoors

Loosen the soil well before sowing. Pumpkin seeds should be sown in warmed soil.

• In place, from mid-May, after frosts, sow 3 seeds in clusters filled with compost
• Water lightly to avoid displacing the seeds
• Keep the soil moist until germination
• When the plants are well developed, thin out, keeping only the best plants: leave about 2 metres in all directions around each plant

Planting Pumpkins

Where to plant it?

Not hardy, the pumpkin is a vegetable grown as an annual. It requires warmth and should be planted in full sun. It thrives in deep, humus-rich soil that retains sufficient water. It naturally finds its place in a vegetable garden where it will need plenty of space; reserve at least 1 square metre for it. To save space and protect your fruits from rot, you can also grow it on supports (trellises, sturdy frames). It is among the most decorative vegetables!

The pumpkin is also very decorative when suspended from trellises

When and how to plant it?

Planting takes place from May onwards, preferably after the Ice Saints, especially in the colder regions.

• Dig a hole at least 40 cm in all directions
• Add well-decomposed manure and/or compost to the soil
• Place the root ball and cover it with loose soil
• Firm down and water to keep the soil moist
• Water generously at the base
• Mulch to keep the soil cool in summer

Cultivation, care and associations

Pumpkins grow quickly in rich, slightly cool soil. They require plenty of water from sowing or planting; water generously and then regularly during fruit formation. Once the fruits are formed, during ripening, limit watering. Mulch around the plants in summer.

These are greedy vegetables that thrive in soil rich in organic matter, loose, deep, and cool. Before planting, they appreciate good fertilisation.

Weed and hoe regularly, especially at the beginning of the growing season. Before harvest, it is advisable to place a tile or brick under the fruits to prevent them from spoiling when in contact with the soil, thus avoiding rot if the soil tends to retain moisture.

Pruning the stems is not obligatory, but it helps promote fruiting and limit overcrowding in varieties with large fruits. Pinch back the exuberant foliage so that the fruits ripen in the sun. From June to September, on the main stem, when it has 4 to 5 leaves, pinch the terminal bud above the 2nd leaf. Then, cut to 2 leaves above each formed fruit, but do not keep all the fruits: as the fruits form, remove the smaller and less vigorous ones. Depending on the varieties and the expected fruit size, keep only 1 to 3 fruits for the larger specimens, 5 to 6 for smaller pumpkins or potimarrons. Remove the branches without fruits to limit the development of vegetation.

Due to its significant growth, it is much more practical to grow pumpkins alone. However, it forms beneficial associations with cabbage, beans, lettuce, corn, or potatoes, chives, onions, and shallots. It develops slowly and will only occupy all the space allocated to it by late summer, allowing for the planting of fast-growing vegetables like salads nearby.

Diseases and Pests

Pumpkin has two known enemies:

1. Slugs and snails that devour young plants: discover our natural slug solutions and our 7 ways to fight slugs effectively and naturally.
2. Powdery mildew, a fungal disease favoured by warm, humid weather, which manifests as white, powdery spots on leaves. It can ultimately affect production. Space the plants well during planting to allow air circulation so that leaves dry quickly in case of rain.

Discover our solutions to prevent and combat powdery mildew in Cucurbitaceae.

Multiplication

Pumpkin sometimes perpetuates itself through spontaneous sowing; it is not uncommon for it to spring up from a compost heap! Therefore, if you already have a plant in the garden, it is easy to collect the seeds, which you can sow the following spring.

It is not uncommon to see pumpkins growing on the compost heap!

Harvest and storage

The Harvest

Harvesting should not be anticipated: pumpkins are harvested at full ripeness as late as possible, but before the first frosts. They are ripe when the neck becomes dry and light yellow, and the foliage is withered. The earliest varieties can be harvested as early as September. The colour of the skin is also a good indicator; for example, at ripeness, it takes on its characteristic orange hue in most cases. Harvest them with the neck, cut close to the stems. In many regions, the flowers are harvested to be consumed stuffed or in fritters, similar to courgette flowers.

Storage

Pumpkins can be stored for several months in a cool room at 10-15°C and can be consumed throughout the winter. Once stored, regularly check that the fruits are not rotting, and remove any diseased squashes. They can also be stored cut into pieces and then frozen, or more simply wrapped in cling film for a few days in the refrigerator.

Uses and nutritional benefits

Pumpkin is consumed cooked in savoury or sweet dishes. It lends itself to multiple recipes, particularly being prepared as a gratin, purée, creams, tarts, soups, and velvety dishes, and even as jams. It pairs well with couscous. A delicious pumpkin curry can be made from it.

Low in calories (26kcal/100 g), it is, however, very rich in vitamins, particularly provitamin A, trace elements, potassium, and has antioxidant properties.

Whether sweet or savoury, pumpkin is delicious