How To Grow Pumpkins / RHS Gardening

Watering

Pumpkins need plenty of water, especially when fruiting. To make watering easier, sink a 15cm (6in) plant pot into the ground alongside each plant, then pour the water into it. This ensures the water goes down to the roots. Insufficient water can hinder fruiting and encourage powdery mildew. It’s also a good idea to insert a short cane A cane is a slender, straight, length of woody plant material, usually bamboo. Canes are primarily used as plant supports. The fruiting stems of blackberries, raspberries and hybrid berries (such as loganberries and tayberries) are also known as canes, so these crops are often referred to as cane fruit. beside each plant, so you can tell where the centre is after it has grown lots of leaves and long shoots. Use rainwater from a butt whenever possible, and preferably water early in the morning or in the evening on hot days, to minimise evaporation. For more water-efficient advice, see our guides below.

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Collecting rainwater Watering vegetables

Mulching

After planting, cover the soil surface with a thick layer of mulch Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings. , such as home-made garden compost, to help hold in moisture and reduce the need for watering. Leave a gap around the base of the plant stem though, to keep dampness away, which could lead to rotting.

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Mulches and mulching How to mulch Organic matter

Feeding

Most pumpkins shouldn’t need feeding, unless you want particularly large (or giant) fruits or the plants are growing in containers. In which case, start feeding once the fruits start to swell, applying an organic-based, high potassium liquid fertiliser every 10 to 14 days.

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Looking after plants in pots Choosing and using fertiliser

Looking after fruits 

Place a tile, brick or piece of wood under developing fruits to keep them off damp soil, which could cause rotting. Also make sure they’re exposed to full sun, to aid ripening – remove a few leaves if necessary – as pumpkins must be fully ripened to store well.

Growing bigger pumpkins

If you want to grow large fruits, then limit the number to just two or three per plant, and for giant pumpkins leave just one, removing any further flowers or fruit that start to form. All the plant’s energy will then be directed into swelling its remaining fruit.