Courgettes are tender, exceptionally productive summer vegetables, ideal for a sunny border, raised bed or allotment. One well-grown plant can yield heavily for weeks, so they suit small gardens. 'Defender' is a dependable AGM choice with good vigour.

When and how to sow

Sow seeds on their edge in individual pots of potting compost from April to May, keeping them warm and bright. Seedlings dislike root disturbance, so avoid over-potting. After the last spring frost, plant out from late May in mild areas or June in cooler districts. Choose full sun and rich soil improved with garden compost, allowing about 90 cm between plants.

Care

Water thoroughly at the base during dry weather, especially once fruits begin forming, and mulch to retain moisture. Feed regularly through summer and remove weeds while small. Large leaves need space and airflow; gently guide stems if they spread across paths. Protect new plantings with cloches or fleece if nights are chilly.

Common problems

Slugs can reduce young plants to stumps, so check around them at dusk and use physical barriers where useful. Powdery mildew often appears later in dry, crowded conditions; water consistently and remove badly affected leaves. Cucumber mosaic virus can distort foliage, so remove affected plants promptly and control nearby weeds.

Harvest

Pick fruits young, glossy and tender, when they are 10 to 15 cm long. Check plants every day or two, cutting with a knife rather than pulling. Frequent picking encourages more flowers and fruits; overlooked specimens quickly swell into marrows. Use freshly picked courgettes for their best texture.

Growing Courgette: frequently asked questions

When should I sow courgette in the UK?

Sow seeds on their edge in individual pots of potting compost from April to May, keeping them warm and bright.

What are common problems when growing courgette?

Slugs can reduce young plants to stumps, so check around them at dusk and use physical barriers where useful.

When is courgette ready to harvest?

Pick fruits young, glossy and tender, when they are 10 to 15 cm long.

General guidance for UK home gardens and allotments. Reference figures are typical values; your exact timing depends on your region, last-frost date and variety. Page updated 19 Sep 2026.