How to grow courgettes

Whichever variety you grow, courgettes taste best when they're picked small

They like a warm, sunny, sheltered position, with rich soil and regular watering. They form large vigorous plants, so need about a square metre of ground each. Alternatively, climbing varieties can be trained vertically up canes or wires and compact varieties can be planted in a large container or growing bag if you’re short on soil space.

There are many varieties to choose from, with fruits in various shades of green or yellow, either long or rounded in shape. You can pick them at any size, but the flavour and texture is best when they’re small. The flowers are also edible. Regular harvesting encourages plants to keep on cropping. If left, courgette fruits will quickly grow into marrows.

There are many courgette varieties to choose from – some forming large trailing plants, ideal if you have plenty of space, while others are bushy and compact, so great in small veg plots and large containers. Many varieties are attractive as well as productive – the fruits can be various shades of green or yellow, striped or plain, and either long or spherical, and the large leaves can be green, mottled or silvery. Spine-free varieties make harvesting easier, while disease-resistant varieties are a good choice in areas prone to damp or humid summers.

For the most reliable croppers, look for varieties with an RHS Award of Garden Merit (AGM), as these performed well in our trials – see our list of AGM fruit and veg and our Recommended Varieties below. You’ll also find courgettes growing in the veg areas of RHS gardens over the summer months, so do visit to compare varieties and pick up growing tips.

Choose a warm, sunny position for courgettes, where you can space plants at least 90cm (3ft) apart. Dig in lots of garden compost or well-rotted manure at each sowing/planting site, into an area roughly the depth and width of a spade’s blade. Ideally do this a few weeks before sowing or planting out, to allow the soil to settle. If you're practising no-dig, mulch the soil at each site ahead of sowing or planting directly into the mulch.

Courgettes are easy to grow from seed. They are best started off indoors in pots in mid- to late spring, but you can also sow them outdoors in early summer, especially in warmer regions.

Young, well-rooted courgette plants grown from seed indoors should be ready for planting out in early summer, once the soil has warmed up. If you haven’t grown your own, you can simply buy young plants in late spring and early summer.

Harden off your courgette plants before planting, to gradually acclimatise them to outdoor conditions, and make sure your planting sites are prepared in advance (see Preparing the ground above). Then carefully remove each young plant from its pot, without disturbing the roots, and plant into the centre of your prepared sites, at least 90cm (3ft) apart. Firm them in gently, then water well. Protect young plants from slugs and snails.

Remove any leaves that become tatty or are affected by powdery mildew. This helps to expose the fruits to the sun, aiding ripening, and makes finding them easier when harvesting.

Courgettes are tender plants, so are susceptible to cold and frost. In early summer, you may find they produce no fruit or the fruits rot when very small – this is caused by cool weather, leading to poor pollination, but should remedy itself once the weather improves. Courgette plants can also be affected by various fungal diseases. See Common problems below for advice on how to spot and tackle these issues. Slugs and snails may eat young plants, flowers and young fruits.