Courgettes are a type of summer squash grown for their elongated fruit that are either yellow or green in colour. Though they are a warm season crop intolerant to cold weather, they are perfectly adapted to growing outdoors in British summers, doing well both in the ground and compost-filled containers such as grow bags and large pots.
Young plants can be bought in garden centres and nurseries in late spring or early summer, but you can easily grow them from seed yourself. For the earliest crops, start the plants inside from the end of April to the beginning of May. Sow seeds 2 to 3cm deep in compost-filled pots that measure about 7cm across the top. Provide both warmth and light by keeping the pots in a conservatory; in an unheated greenhouse or tunnel; or on a south-facing windowsill.
If the compost is warm enough, germination will take place in several days. Don’t let the compost get dry, and give a liquid feed about three weeks after sowing. After preparing your ground or containers, transplant the young plants outdoors towards the end May or the beginning of June when they are big enough – they should have two or three leaves, and their roots should fill the compost. Most courgette varieties are large and bushy when mature, so leave one metre between each plant when transplanting.
If you would rather bypass the need for transplants, sow the seed directly into the ground or containers outdoors in the beginning of June. Even at this late date, the crop should perform admirably in the warmer parts of Britain.
Use pelleted chicken manure to boost the fertility of your soil – if enough is worked into the ground, it should last the whole season. For plants in containers, there is usually a three-week supply of nutrients in the compost. When the three weeks are up, follow on with weekly applications of a liquid feed.
To maximise yields, keep the plants moist throughout the season. Those in containers are particularly susceptible to drying out, and they will need frequent watering – up to once a day – during a drought.
The only consistent problem you are likely to encounter is powdery mildew, a disease that usually occurs during hot, dry spells. Symptoms include white patches on the leaves, and eventually results in the plants becoming unproductive. Other than using resistant varieties, there is little that can be done to control powdery mildew, and to ensure a supply of courgettes right through the summer the best bet is to do a second sowing in June.
Harvesting and cooking courgettes
Each courgette plant produces separate male and female flowers that are easy to tell apart – the females have swollen bases while the males haven’t. The male flowers come on first and provide an early season treat that can be dipped in batter and deep fried. But don’t be greedy and pick too many at a time – they supply the pollen needed by the female flowers for fruit production.
After the female flowers are pollinated their swollen bases morph into the delicately-flavoured fruit prized for their tender skin and soft flesh. Though at their best when 10 to 15cm long, the fruit can be harvested and cooked at virtually any stage in their development. But remember – if you pick them young, more will be produced. But if they are left on the plant too long, not only will there be fewer fruit, but they grow into giant-size marrows enclosed in a tough rind.
Courgette plants bear generous quantities of fruit that, regardless of their size, always have a place in the kitchen:
- Very small fruit with the flowers still attached are delicious coated in a flour and water batter and deep fried until the batter turns a crisp golden brown.
- Fruit that are ‘normal’ size – about 10 to 15cm long – have a shiny, tender skin and can be sliced and slow-cooked in garlic butter; stewed in tomato sauce; or grilled with onions and sweet peppers.
- Bigger-sized fruit with skin that is still tender are ideal grated and cooked in a courgette cake or hollowed out and stuffed with a Mid-Eastern concoction of rice and minced lamb. In a surprising twist, raw fruit can be julienned and substituted for green papaya in a Thai som tam salad – you can hardly tell the difference from the real thing.
- Large marrows, surrounded by a tough rind, can be stuffed and baked the traditional British way, but why bother? Better to create a fusion dish by chopping up the peeled flesh and cooking it in Indian-style curries – what a treat.
Courgettes belong to a group of vegetables called ‘Summer Squashes’ (Cucurbita pepo), which are all managed in the same in the garden. They produce edible fruit of that are harvested during the summer when they are young and tender. Closely related to the summer squashes are the winter squashes, which include some C. pepo and other Cucurbita species. These are harvested in the autumn, when the fruit is mature and the skin hard, and then stored over winter. For more information on winter squash click here.
Renown for their diversity summer squashes are classified according to the shape of the fruit:
Round: Roundish rather than perfectly round.
Scallop: Flattened, with wavy or scalloped edges. Also known as pattypans and custard squashes.
Crookneck: Fat, oval-shaped body topped by a narrow, curved neck.
Straightneck: Fat, oval-shaped body topped by a straight neck.
Just to confuse matters, the term ‘courgette’ is often used to refer to all summer squashes; and ‘marrow’ is used generically for the fruit of any summer squash allowed to fully mature and develop a hard rind. ‘Marrow’ is also used specifically for varieties of courgettes whose fruit are stubby and relatively short and fat. Though these can be eaten when young and tender like any other courgette, the fruit are usually allowed to mature into classic marrows.
Worth the work
Courgettes have it all. They are easy to grow, either in the ground or containers. The plants are productive and are mostly free of pests and diseases. The fruit have a lovely, subtle flavour and are versatile in the kitchen. What more can you ask for?