Arguably the greatest benefit of growing your own fruit and vegetables is the opportunity to savour them when they're at their peak. There are highlights for every season: crisp, green leaves in spring, deliciously sweet strawberries in summer, succulent sweetcorn in early autumn and winter's firm, nutty kail and sprouts.

The veg garden can and should be stuffed with winter brassicas: a range of cabbages, kail, sprouts, a forest of broccoli shoots and kohlrabi.

Visitors to my garden scarcely believe how much space I devote to these goodies, and they're still sceptical when I explain I'll be munching through them over the next six months.

This group of plants is infinitely more nutritious when picked fresh from the garden – cabbages and broccoli in the supermarket can lose up to 80 per cent of their goodness before you've even got them home. As a finishing touch, they may be boiled to death in water, a process that reliably removes any residual nutrients.

Stale brassicas often taste rank and bitter, which is enough of a deterrent, even if you don't carry a gene inherited from our Neanderthal forebears. Our ancestors carried the chemical phenylthiocarbamide in their makeup, helping them avoid bitter and possibly toxic food. But until you've tasted a freshly picked and decently cooked sprout, you cannot know whether you have the Neanderthal super sensitivity or not.

When growing brassicas, the challenge is finding enough space within a three or four-year crop rotation. To achieve this, every cabbage or kail must justify its space, but don't plant too closely. Read the seed packet and stick to the recommended distances between plants – 40-45cm for most cabbages and a staggering 60cm for caulis. Any closer and some of the plants won't heart up properly, so must be consigned to the compost heap or, in my case, provide a tasty side dish for my ducks.

And note whether you're growing the right number of the different varieties. Do you crave more sprouts but can't face another kail leaf? This year I got carried away and planted far too many Minicole, an excellent early autumn cabbage. We had to jettison some tired specimens to let us move on to the later season Kilaton while it was still at its freshest and best.

Then there's the critical question of timing. Seed packets tell us to sow a variety between March and June or February and May. This is UK-wide advice. For Scotland, as a general rule, plump for the middle date with sowings before the summer solstice. If you're doing any sowing from July onwards, choose the earlier month in a given range. When advised to sow between July and August, for example, always opt for July.

Within these guidelines, modify the rule according to your location. Choose an earlier date in the coastal south and delay sowing the further inland and north you live.

But even here, every year is different and can wreak havoc with your best intentions. There's no doubt that the best-laid schemes o' mice an' men gang aft agley. A cool, damp spring followed by a wet, sunless summer gives you bigger cabbages than a sunny summer after a warm, dry spring.

Luckily, we can influence a plant's destiny. Brassicas are admittedly very challenging to grow. Having fortified them against slugs, cabbage root fly and cabbage white butterflies, you must keep protecting them until they reach the plate.

You may need to swathe the plants with insect net or fleece to ward off devouring ducks or pigeons. But weeds keep growing and outer leaves keep dying, even when you can hardly see them. Try to prevent fungal problems by weeding occasionally and by removing decaying leaves.

Be sure to remove old brassicas immediately after harvesting. This prevents the all-too-common sap-sucking grey-green aphids from overwintering in the stems and leaves of old plants.