How to grow courgettes

Courgettes (Cucurbita pepo) are one of the most popular vegetables to grow, and just one plant will provide you with a succession of tender, tasty courgette fruits from mid-summer through into early autumn – expect to pick three or four fruits a week in good weather.

There are many courgette varieties to choose from – some making large trailing plants, ideal if you have plenty of space, while others are bushy and compact, great in small veg plots or containers.

The fruits vary in appearance too – you can choose from various shades of green or yellow, striped or plain, long or spherical, and large leaves can be green, mottled or silvery. Many varieties are ornamental as well as productive.

All courgette varieties like similar growing conditions – lots of sun, warmth and moisture. Most varieties form quite large plants over the course of the summer, needing at least a square metre/yard of ground space. Still, they are prolific croppers, so just a couple of plants is usually enough for a family.

Spine-free varieties make harvesting easier, while disease-resistant varieties are a good choice in regions prone to damp or humid summers.

For the most reliable varieties, look for those with an RHS Award of Garden Merit (AGM), which means they have performed well in RHS growing trials. See Recommended varieties, below.

Courgettes are easy to grow from seed. They are best started off indoors in pots, 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 all danger of frost is past.

You can also buy young plants from garden centres and online suppliers in late spring and early summer.

Courgettes are tender plants and need to be hardened off (acclimatised to outdoor conditions) before they’re planted outside. Do this by putting them in a coldframe for a week. If you don’t have a coldframe, place them outdoors during the day, then bring in at night for a week, then the following week, leave them out in a sheltered spot all day and night.

Courgettes like a warm, sunny position. Prepare the planting site by digging lots of well-rotted manure or garden compost into an area roughly the width and depth of a space’s blade. Then sprinkle a general purpose fertiliser, such as Vitax Q4 over the soil at a rate of two handfuls per square metre/yard.

Carefully remove the young courgette plant from its pot, without disturbing the roots, and plant it into the centre of your prepared site. Firm it in gently, then water well. Space additional plants at least 90cm (3ft) apart.

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 and makes finding them easier when harvesting.

Courgettes are best eaten freshly picked, but will keep in the fridge for up to a week.

They can be frozen, ideally after blanching in boiling water, which helps to preserve their colour and texture.

They can also be made into chutney and other preserves.

Slugs and snails can eat seedlings and young plants, and sometimes flowers and young fruits too, especially in damp weather. Put deterrents in place or use various methods to reduce populations.

Powdery mildew, a fungal disease forms a white powdery coating on the leaves, which dry out and shrivel, hindering the plant’s growth. Water regularly, but avoid wetting the leaves.

Sometimes you may notice no fruit or fruit rotting when very small. This is caused by cool weather in early summer, which results in inadequate pollination. This is usually a temporary problem and pollination will improve once the weather improves.