Common Name: Pumpkin

General Information

Cucurbita pepo is a vigorous, annual climbing plant producing stems up to 5 metres long. These stems tend to sprawl over the ground, though they can also grow into the surrounding vegetation where they support themselves by means of tendrils. Some cultivars have a much more compact growth habit, forming a mound of growth perhaps 1 metre wide.
The plant is widely cultivated in temperate and tropical zones, mainly for its edible fruit but also for its leaves, seed, oil and medicinal uses. In the tropics, it tends to grow better at elevations of 500 metres or more[].

Known Hazards

The sprouting seed produces a toxic substance in its embryo[].

Botanical References

Range

The origin is obscure, but is probably Mexico[].

Habitat

Not known in the wild.

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual Climber
Height	0.60 m
Growth Rate	Fast
Pollinators	Insects
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Cucurbita pepo can be grown from the temperate zone to the tropics, so long as there is a warm growing season of at least 120 days. It can be grown at elevations from 500 - 1,000 metres in the tropics. It grows best in areas where annual daytime temperatures are within the range 17 - 30°c, but can tolerate 6 - 40°c[]. It can be killed by temperatures of 0°c or lower. It prefers a mean annual rainfall in the range 600 - 1,500mm, but tolerates 300 - 2,800mm[].
Requires a rich, well-drained moisture retentive soil and a very warm, sunny and sheltered position[, , , ]. Prefers a pH of 5.5 to 5.9, but tolerates up to 6.8[]. Plants are tolerant of light shade[].
Yields of immature fruits are about 6 - 8 tonnes/ha, while yields of mature fruit may be up to 20 tonnes/ha[].
The plant has long been grown as a domestic crop and a number of different groups have been developed. Botanists have tried to classify these groups, though there is considerable overlap and clear distinctions are not always possible. Since they are very similar in their cultivation needs, we have treated all the groups together in this entry. The botanists classification is as follows:-
C. Pepo pepo. This includes the vegetable marrows, zucchinis, pumpkins and ornamental gourds. There are many named varieties and these can vary considerably in size, shape and flavour[, , ]. The cultivars with larger and rounder fruits are usually called pumpkins, the fruits are harvested in the autumn and can be stored for a few months. The marrows are smaller than pumpkins and generally sausage-shaped. These can also be harvested in the autumn and stored for a few months, but it is more usual to eat them whilst they are still very small, when they are known as courgettes. Harvesting the fruits of the marrows when very small stimulates the plant into making more flowers (and hence fruits) so it can be a very productive way of using the plant.
Pumpkins and marrows succeed outdoors most summers in Britain[], in fact many of these varieties are well adapted to cool growing conditions and therefore do well in the British climate[].
C. Pepo pepo fraterna. This is the probable progenitor of the marrows and so is of potential value in any breeding programmes.
C. Pepo ovifera. This group includes various summer squashes including the acorn, crookneck and patty pan squashes.
C. Pepo ovifera ozarkana. A probable ancestor of the summer squashes, it could be of value in breeding programmes.
C. Pepo texana. The texas gourd, or wild marrow, is another form that could be of value in breeding programmes.
Plants produce both male and female flowers. These are insect pollinated but in cool weather it is worthwhile hand pollinating[]. Most cultivars are day-length neutral and so are able to flower and fruit throughout the British summer[].
There are three major species in this genus that are cultivated for their fruits (C. Maxima, C. Moschata and C. Pepo), and they are often not easy to distinguish. The plant habit is similar and the fruit shape and size within each species are variable. Distinction is easiest by observing differences of the fruit stalk, stems and leaves:-
Cucurbita maxima has a soft, rounded fruit stalk not enlarged at the apex, soft, rounded stems and soft, usually unlobed leaves[].
Cucurbita moschata has a hard, smoothly angled fruit stalk widened at the apex, hard, smoothly grooved stems and soft, moderately lobed leaves[].
Cucurbita pepo has an angular fruit stalk sometimes slightly widened at the apex, hard, angular, grooved, prickly stems and palmately lobed, often deeply cut and prickly leaves[].
A fast-growing plant, trailing forms can be used to provide a summer screen[].
This species does not hybridize naturally with other edible members of this genus[].
Squashes and pumpkins can be differentiated from each other by their fruit stalk, it is angular and polygonal in pumpkins but thick, soft and round in squashes[].
Pumpkins grow well with sweetcorn and thornapple but they dislike growing near potatoes[, , ]. They also grow well with nasturtiums, mint, beans and radishes[].

Edible Uses

Fruit - cooked[, , , ]. Used as a vegetable, it has a very mild flavour and is very watery[]. It is often harvested when still very young when it is called courgettes. The fruit has very little flavour of its own and so is often used as a base for making savoury dishes, the seeds being scooped out of the fruit and a filling being put in its place - this can then be baked[]. A nutritional analysis is available[].

Seed - raw or cooked[, , ]. The seed can also be ground into a powder and mixed with cereals for making bread etc[]. Rich in oil with a pleasant nutty flavour but very fiddly to use because the seed is small and covered with a fibrous coat[]. A nutritional analysis is available[]. The seeds can also be sprouted and used in salads etc[]. Some caution is advised here, see notes above on toxicity.

An edible oil is obtained from the seed[, , , ].

Leaves and young stems - cooked as a potherb[, ]. A nutritional analysis is available[].

Flowers and flower buds - cooked or dried for later use[, ]. A nutritional analysis is available[].

Root - cooked[]. We have some doubts on this report[].

Medicinal

The pumpkin has been much used as a medicine in Central and North America. It is a gentle and safe remedy for a number of complaints, especially as an effective tapeworm remover for children and pregnant women for whom stronger acting and toxic remedies are unsuitable[].

The seeds are mildly diuretic and vermifuge[, , ]. The complete seed, together with the husk, is used to remove tapeworms. The seed is ground into a fine flour, then made into an emulsion with water and eaten. It is then necessary to take a purgative afterwards in order to expel the tapeworms or other parasites from the body[]. As a remedy for internal parasites, the seeds are less potent than the root of Dryopteris felix-mas, but they are safer for pregnant women, debilitated patients and children[]. The seed is used to treat hypertrophy of the prostate[]. The seed is high in zinc and has been used successfully in the early stages of prostate problems[]. The diuretic action has been used in the treatment of nephritis and other problems of the urinary system[].

The leaves are applied externally to burns[]. The sap of the plant and the pulp of the fruit can also be used[].

The fruit pulp is used as a decoction to relieve intestinal inflammation[].

Other Uses

The seed contains 34 - 54% of a semi-drying oil. It can be used for lighting[, ].

Propagation

Seed - sow mid spring in a greenhouse in a rich soil. Germination should take place within 2 weeks. Sow 2 or 3 seeds per pot and thin out to the best plant. The seed requires a minimum temperature of 13°c to germinate[]. Grow them on fast and plant out after the last expected frosts, giving them cloche or frame protection for at least their first few weeks outdoors until they are growing strongly.