How to grow courgettes (zucchini)

How to grow courgettes (zucchini)

Easy to grow and delicious on the BBQ; why not try yellow courgettes

Courgettes are really easy to grow and you can get quite a large number of fruits off just 2 or 3 plants but unfortunately they do need quite a lot of space in which to grow. When they are boiled or steamed they can be quite a bland tasteless vegetable but grill them on the BBQ or cook them with tomatoes, garlic and herbs and they can be elevated to the absolutely delicious.


The seed can be sown in April indoors if you are in the north of the UK or if you want to get a head start and have a sheltered frost free vegetable patch. If sowing indoors place them in a heated propagator at 18 – 21C (65 – 70F). Sow them in their own pot, about 7.5cm (3”) should be sufficient, in good quality seed compost. Place one seed, on its side, in each pot about 1.3cm, (½”) deep, and keep just damp. If sowing in the ground prepare the planting hole where they are to fruit, see below, and space the seeds about 90cm (3’) apart and 2.5cm (1”) deep. Cover with a fleece cloche until the plants are a few centimetres tall and all threat of frost has passed.


They need a sunny site, but not one which gets scorching hot, and good fertile, moisture retentive soil.


Prepare the planting hole by digging in a large forkful of well-rotted farm-yard manure or good quality peat-free compost and a handful of a balanced fertiliser, such as Growmore or blood, fish and bone. If you have germinated the seed indoors harden the plants off before planting outside; do this by putting them outdoors for a few hours a day for a couple of weeks beforehand. You can grow them in a growbag, plant no more than 2 per bag; the disadvantage of this is that they dry out really easily and will need watering morning and evening when it is really hot. You can plant them into tomato rings, filled with extra compost, inserted into the growbag, as this gives them more space to grow and also holds on to more water. When you plant them into the ground take a 2ltr soft drinks bottle, pierce some holes in the cap, cut off the bottom and place in the planting hole, upside down, besides the plant. Then when you water it just fill the bottle and it will deliver the water directly to the roots. The compost heap is a great place to grow them, provided it is well rotted, as it is usually really damp in the centre and retains moisture well. They can be grown in containers but as they are vigorous plants they will need a large pot, at least 45cm (18”) deep and wide, only grow one plant per pot. Use John Innes No 3 compost with a forkful of well-rotted farm-yard manure in the bottom.  


Keep the soil moist at all times, in hot weather this may mean watering morning and evening. Don’t water onto the leaves as this will scorch them, water directly onto the soil. Also the water is wasted as it just evaporates off the leaf surface, especially when they have grown and are in full leaf. Once the first fruits appear feed with a high potash fertiliser, such as Tomorite, every 10 – 12 days.


Pick the fruits when they are about 10 – 15cm (4 – 6”) long, this will ensure that they continue to produce fruits right through the season. Each plant should then produce about 3 – 5 fruits per week.

Pests and diseases

Powdery mildew appears as greyish patches on the leaves and can seriously reduce production if it colonises the whole plant. As soon as you spot it remove the leaves and dispose of in the grey bin, don’t put them on the compost heap or in the green recycling bin. This condition occurs when the plant is dry and too hot so don’t grow in full sun and make sure they don’t dry out.

powdery mildew on courgette leaves

Grey mould occurs when the conditions are damp and humid and as with the powdery mildew affected leaves should be removed and disposed of as soon as spotted. If possible grow somewhere which receives a good airflow.

A poor crop is the result of the flowers not being pollinated which can be the result of the weather being too cool, once the temperature rises the problem should rectify itself.

Recommended varieties

  • Eclipse  -  green; round; good cropper; harvest when small for eating raw in salads, grilled on the BBQ or on skewers; harvest when larger to stuff and roast
  • Firenze  -  green; small slim; heavy cropper
  • Floridor  -  yellow; round; heavy cropper; harvest when small for eating raw in salads, grilled on the BBQ or on skewers; harvest when larger to stuff and roast
  • Orelia  -  yellow; slim; heavy cropper; RHS Award Garden Merit; excellent mildew resistance

BBQ courgettes

To grill them on the BBQ just slice the long fruits lengthways, the round ones into slices or cut them into cubes and thread onto skewers then place directly onto the grate and grill over direct heat for 2 – 3 minutes each side until you have the char lines. Try alternating red and yellow peppers and cubes of halloumi cheese for a really delicious vegetarian meal.

Spicy courgette and tomato bake


  • 2 shallots; finely diced
  • 2 cloves garlic; grated
  • 3 small – medium courgettes; sliced into half-moons about 1.3cm (½”) thick
  • 1 tin chopped tomatoes with herbs
  • 1 teasp mixed dried Italian herbs; oregano, basil, thyme, rosemary
  • rapeseed oil
  • sea salt
  • fresh ground black pepper


Sweat off the shallots and onions in a little rapeseed oil then add the courgettes and cook each side until they are golden brown. Take off the heat add the herbs and the tomatoes and season.

Cook in a pre-heated medium oven, or BBQ, until the tomatoes are bubbling, about 10 - 15 minutes.


Angela Slater

Daughter of a farmer and market gardener so have always had a connection with the outdoors, whether it was keeping animals or producing fruit, vegetables and cut flowers. Along with my work at Hayes Garden World I also have a smallholding, mainly breeding rare breed pigs. I gained an HND and BSc in Conservation and Environmental Land Management, as a result I am an ardent environmentalist and have a keen interest in environmentally friendly gardening. In my time at Hayes I worked for several years in the Outdoor Plant and Houseplant areas.