Pumpkin

Pumpkin (Cucurbita moschata)

Other common names: 南瓜

Pumpkins are a popular fruit used for a variety of desserts, snacks and dishes in both Asian and Western cuisine. In addition to the mature fruit, young shoots and mature seeds can also be eaten.

Most tropical pumpkin varieties are much smaller than their temperate counterparts. They can be yellow, orange, or dark green when ripe.

An annual crop, these plants are often grown in rotation with other fruiting climbers.

This plant is part of the Cucurbita or melon family, which includes other popular edible fruits like bitter gourd, winter melon, and cucumber.

Sun and soil needs:

This vine does best in full sun gardens with a minimum of 6 hours of direct sunlight. This plant can also grow with 4-5 hours of direct sunlight and at least 6 hours of indirect sunlight, but will produce less fruits.

Plants do best in pots with loamy soil at least 30cm deep, or in true ground. The plant can be grown in smaller pots about 20cm deep, but growth will be slower and the plant will produce less fruit.

This vine is vulnerable to heat stress during the dry season. Water it regularly and mulch the base to prevent water loss.

Sowing seeds:

Seeds can be sown directly into pots or the ground around 15-30cm apart. Lightly water the soil until damp, once a day. Seeds should sprout within 10 days.

The seedlings are generally resilient to most environmental factors but may be vulnerable to being eaten by snails or birds. Protect your young plants with a DIY cloche or netting.

Growing:

Pumpkins will produce more flowers and thus more fruit when fed with fertilisers high in Phosphorus and Potassium. Plants can be fertilised regularly once a month after the first flower for a fuller crop.

As a fast-growing vine, this plant can be grown on the ground or trained up a sturdy trellis. The fruits can get quite heavy if they are hanging off a trellis and can be supported with a cradle to prevent damage to the rest of the plant.

As with all members of the melon family, this plant is bee pollinated and produces male and female flowers. To encourage the formation of more fruits, it is best to have at least 3 separate plants growing in the same area to have both male and female flowers available, and to have bee-attracting plants within the garden to encourage pollination. If your garden lacks bees, the plant can also be hand pollinated.

Because the vines will grow on top of each other, it is a good practice to prune regularly and remove dead leaves and vines to improve ventilation and allow light to reach more of the plant.

Direct sunlight can damage the fruit. Allow leaves to grow over the fruit, or protect it using a cloth cover.

Allowing the fruit to sit in water can cause rotting. Keep the underside dry by placing it on a platform if the fruit is growing on the ground.

Harvesting:

Plants can be harvested for fruits around 4 months after sowing. The best time to harvest young shoots, stems and ripe fruit is in the early morning, before 9am.

Pumpkin fruits are ripe for harvesting when the stalk holding the fruit starts to shrivel and turn brown. The pumpkin can be harvested and kept for another two weeks for the skin to harden and for the flesh to become sweeter. Both the flesh and seeds of ripe fruit can be eaten.

Regularly harvest the mature fruit to encourage the plant to keep producing.

The plant will continuously produce fruit for about 6 months to a year before declining.

Harvest cycle:

Propagation:

This vine can be grown via seeds. Seeds can be taken from mature fruit for immediate planting.

Common problems & solutions:

If your plant has few to no flowers, you can fertilise the plant with fertilisers high in phosphorus and potassium. These nutrients encourage root and flower growth, which are important for the plant to produce more fruit.

However, if your plant is producing lots of flowers but is not bearing fruit, you may not have female and male flowers present in the same area together. Pollen from the male flower needs to be transferred to the female flower before the female flower can become a fruit. This process is called pollination and is important or the formation of many edible fruits. Vines from the melon family generally produce male flowers before female flowers. Having at least 3 plants of varying ages in the garden will make both male and female flowers present for pollination to happen.

Many plants require pollinators to help them fruit. Bees, butterflies, birds and even beetles transport pollen from one flower to another, pollinating your crops and increasing their fruit yield. Attract some pollinators to your garden by growing pollinator-attracting crops.

Aphids, mealy bugs and whiteflies often infest the plant if it has underlying problems like repeated wilting from heat stress. Mechanical pest control methods like pruning the infested parts are the best methods for managing these pests in the short term, but resolving the underlying problem will prevent them in the long term.

Wilting leaves during hot weather is a sign of heat stress. Increase the number of times the plant is watered daily, and apply mulch at the base to prevent water loss.

The fruit is prone to rotting if it is left in contact with the wet ground. Consider placing the fruit on a well-draining platform or grow the plant up a trellis to encourage the fruits to hang downwards.