How to grow squash

Squash are an increasingly popular veg and love a warm summer. They take up quite a bit of space so they're best suited to growing in a garden or allotment.

Make more of your garden - get our free Gardening newsletter for top tips from our experts

How to grow squash: month by month

Best squash varieties

Which? members can log in now to see the full results and which are our Best Buy varieties. If you’re not a member, join Which? to get instant access.

How we test squash

We chose 14 varieties, including three previous Best Buys and some butternuts, as we know how popular these are. We sowed seeds in modules in May and kept them in the greenhouse until they were large enough to plant out. The plants were hardened off and, in June, put outside in their final positions at our trial site in Cambridgeshire. This was in a bed in full sun into which we’d dug well-rotted organic matter. They were planted through slits in a black plastic mulch, in rows 1.5m apart, to help suppress weeds, warm the soil and reduce moisture loss. Plants were spaced 1.5m apart in the rows to give them plenty of room. Slug and snail damage can be a common problem, so we used organic slug pellets. We harvested the fruit in mid-October, noting how many were ripe by this point, as some varieties struggle to ripen many fruits before the frosts arrive. Then, with the help of experts, including a chef, we conducted a taste test to find the most delicious varieties.

When to sow

Indoors

Sow the seeds into individual small pots or module trays containing a Best Buy compost for sowing seeds in late April or May. They're damaged by frost so keep them in a greenhouse or on the windowsill until the danger of frost has passed in mid- to late May or early June.

Caring for your plants

Planting

Grow squash in a sheltered spot. Soil should be moist but well drained and rich in organic matter. Space plants 1.5-3m apart, depending on the variety. Mulch after planting to retain moisture, either with garden compost or plant through slits in black plastic mulch.

Feeding

Top dress the soil with general fertiliser after planting. Feed every 10-15 days with a tomato liquid fertiliser when fruits start to swell. As fruits mature, cut the foliage away to help them ripen.

How and when to harvest

Harvest in: September to October

Leave fruits on the plant for as long as possible. Be sure to keep  an eye on the weather forecast and pick all the fruits before the first frosts, cutting with secateurs to leave a long stalk.

Storing

Leave fruits in the sun or in a greenhouse for around 10 days after harvesting to thicken the skin, then bring them indoors to a cool, dark place. Pumpkins and butternut squashes last up to December so use them first. Other squashes will remain in good condition until the following spring.

Common growing problems

Slugs and snails

Watch out for symptoms of damage, such as holes in foliage and silvery trails, especially just after planting out. Pick off any you find, put down organic slug pellets or apply a biological control (effective against slugs only).

Read more about slugs and snails.

Powdery mildew

A fungal disease whose symptoms are white powdery growth on leaves. It usually affects plants in late summer when conditions are dry. To prevent it, keep plants well watered and mulched. There is no chemical control.

Read more about powdery mildew.

Cucumber mosaic virus

This affects many more plants than cucumbers. Symptoms are mottling and yellow on foliage, stunted growth and distorted leaves. Destroy affected plants and be careful not to transfer the virus through tools. Control weeds and aphids, which often harbour the virus. There are no chemical controls available.

Read more virus