Pumpkin plant care: how to prune, water & fertilise pumpkins


With a passion for growing installed at an early age, I have always been happiest outdoors in nature. After training as a professional gardener and horticultural therapist, I currently run horticultural therapy and community kitchen gardens in the UK, helping others access the many physical and mental health benefits of growing vegetables, fruit and plants.

Favourite fruit: apples and pears
Favourite vegetable: asparagus

With their attractive autumnal colour and many culinary uses, pumpkins are a great crop to grow at home. Discover all there is to know about caring for pumpkins.

Caring for a large pumpkin
With the right care, pumpkins are easy to grow [Photo: Nadzeya Pakhomava/ Shutterstock.com]

Pumpkins (Cucurbita pepo) are native to North America where they have been grown for thousands of years. Despite being introduced to the UK in the 16th century, pumpkins have not always been as popular as they are now. With so many pumpkin varieties available in a range of different colours, shapes and sizes, choosing which cultivar to grow can be tricky. After planting pumpkins, you will need to care for them correctly until harvest time. Read on to learn how to fertilise, prune and water your pumpkin plants to ensure the best crop.

Fertilising pumpkins

With their impressive fruits, it is no surprise that pumpkins and squashes are heavy feeders and grow best when planted in a rich and fertile soil. Nevertheless, for pumpkins to reach their full potential, you need to fertilise them to provide the extra nutrients they require.

Yellow pumpkin flower on plant
Fertilising pumpkins can help ensure a bountiful harvest [Photo: Tricky_Shark/ Shutterstock.com]

Before, or at the time of planting, incorporate a generous amount of well-rotted manure, garden compost or slow-release fertiliser to enrich the soil. Our Plantura Tomato Food releases slowly and only needs to be applied twice during the pumpkin season, once when planting and once when they start to flower. It is great for fertilising pumpkins because it is high in potassium, which helps with fruit production.

Tomato Food, 1.5kg
Tomato Food, 1.5kg
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  • Perfect for tomatoes, chillies, courgettes, cucumber & more
  • For healthy plants & an abundant tomato harvest
  • Long-lasting fertiliser that is free from animal products - child & pet friendly

Pumpkins can also be successfully grown in large containers or pots. However, when grown this way, you will need to fertilise the plants more often due to the limited amount of soil and nutrients leaching out over time. A liquid fertiliser, such as our Plantura Liquid Tomato Food, is best for pumpkins grown in pots, as it is easy to apply. Once the fruits start to appear, apply when watering your pumpkins. Feed pumpkin plants every 2 weeks to help prevent any nutrient deficiencies.

Liquid Tomato Food, 800ml
Liquid Tomato Food, 800ml
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  • Perfect for tomatoes & other vegetables
  • Liquid fertiliser for healthy plant growth & an abundant harvest
  • Quick & easy application - child & pet friendly

Tip: due to the pumpkin’s poor tolerance of high salt concentrations, it is best to use organic fertilisers, which, unlike mineral types, are less likely to cause high salt levels through overdosing.

Pumpkin pruning

Pruning pumpkins is not essential. However, pumpkins can naturally tend to produce numerous fruits that are subsequently on the small side, which depending on your requirements, can be a good thing. But if you want to grow a smaller number of larger pumpkins, you can prune them to help their energy go into just a few fruits. Since pumpkin vines can grow extremely long, they are also pruned to stop them from outgrowing their allotted space as well as to remove dead or diseased material. Whatever the reason for pruning your pumpkins, we recommend you use sharp and clean secateurs to keep wounds small and to minimise disease transference.

A pumpkin plant being pruned
Use clean and sharp secateurs to trim pumpkin vines [Photo: Stsvirkun/ Shutterstock.com]

If you are aiming for larger fruits, once the female flowers have begun to swell and form the number of pumpkins you wish to keep, cut away the vine’s growing tips. You can also remove any surplus fruits and male flowers at this point, identifiable by their long thin stems. As the pumpkins develop, you will want them to receive as much sunlight as possible to grow and ripen before winter arrives. Gently move the fruits out from under any overshadowing leaves so that they get enough sunlight.

Tip: pumpkins can rot when left on wet soil for an extended period. To prevent this, place a piece of wood or flat stone underneath the fruits to lift them up off the ground.

How often to water pumpkins?

Pumpkins are thirsty plants and prefer to grow in a moisture-retentive soil. However, pumpkins do not like saturated soil, so avoid any sites that are prone to waterlogging. Water pumpkins regularly to keep the soil moist and stop it from completely drying out, particularly during hot and dry spells when powdery mildew (Podosphaera) is a risk. Where possible, water pumpkin plants using harvested rainwater, which is lower in lime than tap water, especially if you live in a hard water area. To help channel the moisture down to the roots, you can sink a 1L pot into the soil, which when filled, will slowly and deeply irrigate the plant. We go over how to do this in detail in our article on ollas.

Preventing moisture loss when growing pumpkins is key during the hot summer months. To help reduce evaporation, mulch around the plants and only water them early in the morning or evening, when the temperatures are at their lowest.

Watering a young pumpkin plant
Pumpkins require moist soil to produce a good harvest [Photo: Jurga Jot/ Shutterstock.com]

Tip: when watering pumpkin plants, it is important to avoid wetting the foliage. While this is sometimes easier said than done, it helps lower the risk of pumpkin downy mildew (Pseudoperonospora cubensis). Growing smaller pumpkin varieties vertically up a trellis can also help keep the foliage dry.

Does pumpkin care depend on the variety?

In general, most pumpkin and squash varieties require a similar amount of sunlight, water and nutrients, which makes their care alike. However, if you want to try growing one of the enormous cultivars such as ‘Atlantic Giant’, you will need to remove all but one of the fruits to channel all the plant’s energy into its growth.

A single giant atlantic pumpkin
Some cultivars such as ‘Atlantic Giant’ can produce huge pumpkins [Photo: Studio Barcelona/ Shutterstock.com]