How to grow courgettes
Learn how to sow, plant and grow courgettes, in this practical Grow Guide.
Jobs to do each month:
- April or May: sow seeds indoors
- April to May: pot on seedlings indoors
- Late May to early June: sow seeds outdoors for a late crop
- May to June: plant out young plants
- July to October: harvest fruits
Courgettes are easy to grow and highly productive plants, bearing masses of delicious, nutty crops for use in summer dishes and salads. They are prolific croppers and take up a lot of space, so just two or three courgette plants are enough to feed a family, with enough left over to give to friends. You can buy young courgette plants at the garden centre in late spring, but they are easy to grow from seed.
How to grow courgettes
Buy young courgettes at the garden centre in late spring, or sow courgette seeds indoors in April or May, in pots of peat-free, multi-purpose compost. Pot on seedlings when they're big enough to handle, and plant the young plants outside when all risk of frost has passed. Alternatively, you can sow seeds direct outside in late May or early June. Courgettes are hungry plants, so do well grown in soil enriched with plenty of well-rotted horse manure or compost and need feeding weekly with a high-potash feed, such as tomato food. Water plants regularly to keep the soil moist. Harvest courgettes when they are around 10cm long – leaving courgettes to grow larger will reduce the plant's vigour and fruiting potential.
How to sow courgette seeds indoors
Fill a small pot with peat-free, multipurpose compost that has been kept in the greenhouse, so that it is already warm. Firm well and press a couple of seeds, on their sides, into the compost.
Cover the seeds with compost or vermiculite, which is warm and free-draining and helps stop young seedlings from rotting during cool night temperatures.
Soak with tepid water and place in a propagator or a tray covered with a clear lid, at a temperature of 20°C.
When seedlings appear, move stronger ones to larger pots. Throw away weaker seedlings. Grow on indoors until ready to plant outside in late spring, after the last frost. Space plants 90cm apart, then mulch the surrounding soil generously to hold in moisture.
Watch Monty Don's video guide to growing courgettes (and pumpkins) from seed:
Growing courgettes from seeds outdoors
You can sow courgettes directly outside in late May or early June, for later crops. Prepare the site well by digging in lots of home-made compost or well-rotted manure. Sow one or two seeds, around 90cm apart, 2.5cm deep. Cover with a transparent glass or plastic cloche and leave this in place for a few weeks after young seedlings have appeared. Remove the weaker seedlings so that just one remains in each position. Be sure to protect the young plants from slugs and snails.
How to plant out courgette plants
Plant out your courgette plants when all risk of frost has passed – usually from late May. Choose a sunny, sheltered spot, and give them plenty of room, as they can grow into large plants. Allow a square metre for each plant, or one per growing bag. Prepare the soil well beforehand by digging in plenty of compost or well rotted manure. Mulch around the plant with more compost or manure, to preserve moisture. Be sure to protect the young plants from slugs and snails as they are very vulnerable until they are established.
In this video, Monty Don demonstrates how to plant out courgette plants:
How to care for courgette plants
Moisture is the key to success when growing courgettes. A constantly just-moist soil is essential if plants are to crop to their full potential. It's therefore important to water courgettes regularly and apply a thick layer of mulch around the plants, to hold water in the soil. In dry conditions, most varieties produce mainly non-fruiting male flowers. To encourage female (fruiting) flowers, water generously and regularly.
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Apply a high potash feed, such as tomato food, once a fortnight to promote growth and flowering.
In this video, Monty Don offers tips on watering and feeding, for the best results:
Cut courgettes while they are small (about 10cm long is ideal), rather than leaving them to grow to the size of marrows – this will help to encourage more courgettes to develop over a longer period. Cut them off at the base with a sharp knife, or twist the stalk sharply.
Watch Monty Don's video guide to harvesting courgettes:
Growing courgettes: problem solving
This happens if the plant is only producing male flowers, which do not produce fruits. The production of male flowers is usually due to dry conditions. Keeping the soil consistently moist should solve the problem; remember to feed regularly with a high potash feed to promote the production of flowers. You can eat the male flowers – they are a delicacy in many Mediterranean countries and are delicious stuffed and baked or deep fried.
Slugs and snails
Young plants are extremely vulnerable to slugs and snails and can be demolished overnight. Add some kind of protection as soon as you have planted out. Deter slugs by putting crushed eggshells or a copper ring around the stem base, or use a biological pest control. Use wildlife-friendly slug pellets as a last resort.
Courgette rot is a common problem in damp weather. It often spreads from the faded flower into the end of the courgette itself. Never water plants from above – always direct water down onto the soil around the stem. Keep a close eye on plants during wet weather and remove any soggy flowers from the end of developing fruits.
The white powdery coating on a curcubit’s leaves is made up of spreading fungal spores. This affects the plant’s performance, with growth, flowering and fruiting all being affected. Healthy plants are less susceptible, so make sure they are well spaced and have good air circulation around them. Mulch the area to lock moisture in the ground and give plants a regular drink. The moment mildew is seen, immediately prune out and destroy the affected leaves.
Grey, fluffy growth on plants is grey mould (botrytis). It's especially common in damp or humid weather. Cut out any affected areas and remove any dead growth on the ground. Avoid splashing the leaves when watering.
Preparation and uses of courgettes
Courgettes can be steamed, fried or grilled. Spherical varieties are perfect for stuffing then baking.
Looking for inspiration on how to use your courgettes? Our friends at olive have curated a delicious collection of courgette recipes, including fried courgette flowers with honey and vinegar.
Courgettes are best used fresh, but can be kept for a short period of time by storing in a cool, dry place. Alternatively, turn gluts into chutneys or pickles.
Great courgette varieties to grow
- ‘Defender’ – a heavy cropper with green fruits and good disease resistance
- Buy courgette 'Defender' seeds from Thompson & Morgan
- ‘Gold Rush’ – with long, golden-yellow fruits
- Buy courgette 'Gold Rush' seeds from Thompson & Morgan
- ‘One Ball’ – the vibrant yellow, spherical fruits have a creamy flesh
- Buy courgette 'One Ball' seeds from Dobies
- ‘Tondo di Nizza’ – tennis ball-sized, pale green fruit
- Buy young courgette 'Tondo di Nizza' plants from Harrod Horticultural
- 'Venus' - a compact patio variety, ideal in pots
- Buy courgette 'Venus' seeds from Just Seed
- ‘Zucchini’ – prolific, classic green courgette
- Buy courgette 'Zucchini' seeds from Dobies
- 'Ambassador' – high-yielding variety, bears dark green fruit with a crisp white flesh, over a long season.
- Buy courgette 'Ambassador' seeds from Thompson & Morgan
Try a climbing courgetteAlthough most courgettes trail along the ground, there are climbing varieties for those short of space. 'Black Forest' and 'Tromboncino' are easy to train up a stake, as long as they are regularly tied in as they grow.
Growing courgettes with sweetcorn
You can grow courgettes as companion plants with other crops such as beans and sweetcorn. In this video, Monty Don plants a raised bed with tall, slow-growing sweetcorn, then fills the gaps with low-growing courgettes. As they both like the same growing conditions, they make good companions and will give you two crops in one bed:
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