Pumpkins: profile & diseases
Not only do pumpkins look great, but they are also a fantastic vegetable to use in the kitchen and are becoming ever more popular. Discover more about the versatile pumpkin, its health benefits and some of the diseases it can succumb to.
Originally from North America, where they are a key commercial crop, pumpkins (Cucurbita) are becoming increasingly popular here in the UK as well as Europe. Easily recognisable by their distinctive fruits, pumpkins are also known for their large flowers and climbing or trailing vines. Available in shops in the autumn for decorating or eating, there are also a myriad of different varieties to grow at home.
Pumpkins: profile and characteristics
As members of the Cucurbitaceae family, pumpkins are a type of winter squash that has been cultivated for thousands of years. Although typically orange, round and ribbed, there are numerous pumpkin and squash varieties available in such an array of colours, shapes and sizes that decorative displays are put on publicly for show. Pumpkins are primarily derived from Cucurbita pepo species, but the larger fruiting Cucurbita maxima and butternut varieties (Cucurbita moschata) are also widely grown.
Although native to warmer climates and susceptible to frost, you can successfully grow pumpkins here if you give them the correct growing conditions. Cultivated from large, flat and oval seeds, pumpkins require a long growing season and generally take 90 to 120 days from sowing until harvest time. Most pumpkins produce four to six fruits per plant. Their long vines generally form a spreading habit, although bushy varieties are available as well. Attached to the vines on hollow stems, pumpkin leaves are large and tend to be either lobed or serrated. In early summer, large yellow flowers appear in both male and female forms. You can tell the difference by the fact that the female flower displays a swollen ovary behind the petals. Loved by bees, the star-shaped flowers are pollinated before the female flowers develop the long-awaited pumpkin fruits. Pumpkins generally develop a shallow root system, so any weeding around pumpkin plants should be performed with care.
Did you know? Although they are members of the same Cucurbitaceae family, patty pans and courgettes (Cucurbita pepo) are actually types of summer squash and as such they are grown differently.
Tip: the stems and leaves of pumpkin plants are often covered in small hairs and can be uncomfortable to handle. Wear gloves to avoid being prickled and any potential skin irritation.
Are pumpkins fruits or vegetables?
If you are wondering whether the pumpkin is a fruit or a vegetable, the answer is not as clear-cut as you might hope. In the past, fruits and vegetables have been named as such based on how they are eaten. Confusingly, the pumpkin is used like other fruits for sweet-tasting dessert pies but also in savoury soups. However, pumpkins also produce seeds within their flesh and grow from flowers, and for these botanical reasons, they are classified as a fruit. Furthermore, pumpkins can also be considered a berry. So, even though pumpkins are commonly eaten and grown like a vegetable and are often found in the vegetable section of a supermarket, they are technically a fruit.
Tip: even though they are classified as a fruit, not all types of pumpkin and squash are safe to eat. Find out more about which pumpkin varieties are safe to eat in our other article.
Diseases and pests
Pumpkins require a warm and sunny growing season to produce a good harvest; wet summers can reduce quality and yields. Along with the weather, pumpkin diseases and pests can be troublesome, and if not treated, can lead to crop failures.
Perhaps the most commonly faced problem gardeners encounter when growing pumpkins is powdery mildew (Podosphaera). Clearly identifiable by its powdery white spores that cover the leaves, powdery mildew can lead to the foliage shrivelling and dropping. It is most prevalent in humid conditions and where airflow is limited. Due to its airborne spores, powdery mildew spreads rapidly and swift remedial action is necessary. If you recognise pumpkin powdery mildew, remove any infected leaves to prevent it from spreading further.
Prevention is vital in the fight against powdery mildew on pumpkins and new cultivars are now available with better resistance. Along with growing resistant varieties, fertilising and watering your pumpkins correctly and ensuring good air circulation between plants can help prevent powdery mildew. Fungicides are available to treat powdery mildew but should only be used after other non-chemical controls have been tried. As powdery mildew can overwinter on the foliage, it is important to remove pumpkin plants at the end of the season. Dispose of them carefully to help prevent powdery mildew from returning.
Downy mildew (Pseudoperonospora cubensis) can also occur on pumpkins. You can identify downy mildew by angular yellow marks on the leaves that merge and turn brown over time, resulting in poor photosynthesis. The airborne spores are highly transmissible and can affect nearby plants, leading to a reduction or complete loss of fruits. Downy mildew is most prevalent during periods of high humidity and leaf wetness. Increasing air circulation and avoiding the foliage when watering can help prevent downy mildew from taking hold. If you identify downy mildew on your pumpkins, the only option is to dig up and dispose of the plants, as there are no treatments available for home growers.
Tip: fertilising your pumpkin plants can help maintain plant health and encourage a healthy harvest. A liquid tomato food is great for fertilising pumpkins, as it can be easily applied when watering. Our Plantura Liquid Tomato Food contains the key nutrients nitrogen, phosphorus and potassium that are necessary for healthy growth and fruit production.
- Perfect for tomatoes & other vegetables
- Liquid fertiliser for healthy plant growth & an abundant harvest
- Quick & easy application - child & pet friendly
Grey mould (Botrytis) is a fungal disease that affects many plants including pumpkins. Identifiable by brown or grey furry mould that develops on the plant, it enters the plant at wounds and can also affect plants under stress. As with powdery mildew, preventative measures which include good plant hygiene can help prevent grey mould on pumpkins. If you spot grey mould, cutting away the infected parts and increasing air circulation wherever possible can help treat it. Along with this, clearing up any dead plant material from the soil can help prevent it from recurring.
Young pumpkin plants can be especially vulnerable to slug and snail (Gastropoda) damage. Control measures include picking slugs and snails off by hand, installing barriers and encouraging predatory wildlife into your garden. Only planting out healthy and vigorous pumpkin plants that can withstand some potential damage can also prove successful. For more tips and tricks on protecting your pumpkin plants from snails and slugs, check out our article on how to get rid of slugs and snails.
Tip: practising a 3 to 4 year crop rotation not only helps enhance the soil’s fertility and structure but prevents a build-up of any potential soil-borne diseases.
As well as being delicious, pumpkins are highly nutritional and have many health benefits. Pumpkins are rich in vitamins C and E and can support immune health and protect against infections. They also contain high levels of beta carotene, which is an antioxidant that supports eye health. Along with this, pumpkins are high in fibre, which is necessary for a healthy digestive system.
In addition to the flesh, the health benefits of pumpkin seeds are also widely recognised. Packets of pumpkin seeds are easy to buy at the supermarket and make a delicious healthy snack and can add some crunch to salads. Pumpkin seeds, which are abundant in iron, magnesium and potassium, are said to help support healthy heart function and even reduce inflammation.
Pumpkins are well suited to our climate and are easy and fun to grow at home. Learn all about growing your own pumpkins in our expert article.