I like growing courgettes. There is something immensely satisfying about a plant that grows so quickly, has such showy blooms and that almost kills itself cropping. But what is the difference between a courgette and a marrow?

Basically it is just a matter of size, and if you are sniggering, then be warned that it is more accurately a matter of maturity –  so stop it!

Courgettes and marrows are the same species and almost identical plants. But marrows tend to be sprawling plants while courgettes are usually compact or bush habit. Courgettes also have the innate ability to produce more flowers and fruit. Marrows are a traditional British crop and usually allowed to become enormous, so that plants don’t produce many fruits. I think the need to allow marrows to become huge (and thus inedible) derives from flower shows, where the biggest marrow carries huge kudos, and 70s sitcoms where it would be the but of many a joke. Marrow is basically tasteless and mum used to peel, slice and boil marrow and, covered in a peppery white sauce and butter it was quite nice. But it tasted of nothing and left the plate swimming in water.

Courgettes, which are basically baby marrows, are much nicer.

Both are derived from Cucubita pepo, a Mexican species which has been domesticated for millennia and has been developed into lots of kinds. These include acorn squash, vegetable spaghetti, crookneck squash (below), patty pan squash and pumpkins.

So now I have used that dreaded word – squash. Squash confuse people but basically, for practical purposes, although they can be derived from many species, there are summer squash, eaten fresh when immature (and largely C. pepo) and winter squash, which are allowed to ripen on the plant and eaten, after storage, in winter. These are derived from many species, some of which do not mature well in Ireland outside.

Vegetable spaghetti is a curious vegetable that emphasises the stringy nature of marrows. The mature fruit are picked, steamed or roasted and the stringy insides forked out (having removed the central seed cavity) and mixed with butter and pepper. It is a lot nicer than it sounds.

Courgettes do not have to be boring or green. I prefer yellow courgettes because they seem to be firmer and less watery to me. The pale, greyish, Lebanese courgettes are also alleged to be extra-fine and they certainly make a change. You can get round courgettes too, which are ideal for stuffing, but I grew up on too many meals of stuffed marrow, hollowed out and filled with mince, to take the trouble too often.

Courgettes are relatively trouble-free. In the USA there are lots of pests that we, mercifully, do not see. They grow rapidly too. One of the main issues is that young plants start the season producing male flowers. Any one plant will produce male and female flowers and only female flowers will produce fruit. This annoying habit cannot be avoided but if you have only one or two plants you may not get male and female flowers opening the same day at first. You can now get parthenocarpic hybrids which will produce fruits even if not pollinated and these are well worth a try. Remember that courgettes are best eaten when they are small so you need not despair if there are not male flowers when the females open – you can cut them the day the flower opens, then dip them in batter and fry.

Courgettes are large, leafy plants and are best in a sunny spot sheltered from strong wind. They need lots of feeding and watering so dig in lots of compost and mulch with whatever organic matter you have to feed them and keep moisture in the soil.

I never understand why people buy courgette plants because the plants are so easy to grow and will be ready for planting out just a month or so after sowing. A plant costs the same as a packet of seeds and then you can choose the variety. Good hybrids cost a bit more and may contain only eight seeds but you can sow four and keep four for next year.

You must plant them out when they are small, and vigorous. Straggly plants with small leaves, already blooming, will never do well so do not sow until six weeks before your ‘planting out’ date, late May here. The plants will be killed by the merest kiss of a frosty night. The plants above, with two seed leaves and one fully expanded leaf, are at the right stage for planting.

Sow one or two seeds, on their sides, in cell trays or small pots of multipurpose compost, about 1cm deep, in April. Keep at 20c and moist and they will start to appear in a week or so. If both seeds grow pinch out the weaker. Watch for mice, which love the seeds, and slugs and snails after planting out. Plant them 80cm -10cm apart. They do well in pots of multipurpose compost if well watered and fed.

Top Tips

Grow a few varieties

It is easy to have a glut of courgettes so don’t sow lots of seeds. Three plants will keep a couple happy. But they don’t go on for ever so it makes sense to grow a couple of varieties and to stagger sowings. Sow three of each of two varieties in April and then make a second sowing in early June. The second sowing will give courgettes into autumn because, in the dry weather of August (LOL) older plants may get mildew.

Mildew

Courgettes are prone to the debilitating fungal disease powdery mildew. This coats the leaves with powder and reduces the vigour of the plants. It is most common in hot, dry weather. Keeping plants moist and well fed will reduce mildew. Do not confuse it with the silvery spots and blotches on courgette leaves – this is normal.

Pick the *%$*£ things

At their peak, courgette plants are very productive. You need to pick them when they are small, just a few days old, or they will rapidly become large and less tasty. Tiny courgettes are delicious and they lose their quality every day they get bigger. And, of course, when big you only need one for the meal and you quickly fall behind with picking. If you are not going to use them just cut them off and compost them rather than let them mature. If the plant has to sustain old, swelling fruits it will give up making new ones. Picked young, courgettes are tasty and nutty enough to be used raw in salads so you don’t have to let them get to the size of supermarket courgettes.

Water them

Few veg plants respond as well to extra water as courgettes. Never let them dry out.

Watch for virus

The worst problem is virus, spread by aphids. The leaves may become mottled with yellow but the fruits will become distorted. There is no cure. Pull up and compost the plants. Chickweed is a ‘carrier’ for the disease so be ruthless in your battle against it.

Soggy ends

In wet weather the flower on the end of the fruit can rot and the rot will spread down into the fruit. In wet weather it is worth going over the plants and flicking the old flower off the end of the fruit to prevent rot. This is only necessary from September onwards in most seasons.