I’VE just checked the price of purple sprouting broccoli in our local supermarket.

They want nearly two quid for a small, limp portion, sweating under the lights in cellophane packaging.

That’s more than the price of a packet of 50 seeds, which should last for a good few years. And if you sowed some at about this time last year, then with any luck right now you’ll be picking more purple sprouting than you know what to do with.

Over the years I’ve grown a number of varieties, but I always seem to come back to one called Claret, which is listed in several seed catalogues.

I find it more reliable than most, with a very good flavour, and heavy yields.

In my garden, in the West Country, it starts cropping around mid-April and carries on for about four weeks.

In theory, by growing both “early” and “late” cultivars, you can extend the picking season from January to May.

In practice, that’ll depend to some extent on what the weather does.

It can be worthwhile, though, if you’ve got the space, especially since some seed companies sell packets which contain a blend of early and late.

The seeds can be started indoors in March or April or direct into the soil outside in May or June. Or, of course, if you miss all the sowing dates, you can buy young plants from garden centres or online.

I like to sow them in an unheated greenhouse during April, in a small seed tray, using multipurpose or seed compost. Once the seedlings have formed a couple of pairs of leaves and are something like four or six inches tall, move them on singly to pots.

I put them in fairly large pots — five or six inches — because they’ll be sitting in them for a while yet.

Obviously, if you’ve sown them outdoors, then the issue doesn’t arise — just thin them out so that they’re not crowding each other.

In July or August I put the plants out in their final quarters. They need good, fertile soil, preferably enriched with compost or manure. This not only feeds them but prevents them drying out during the summer.

The ground also needs to be firm, so that they won’t get rocked by winter winds.

After you’ve planted them, stamp the ground down with your boot all round them.

They’ll need tying to proper, solid timber stakes, as they’re going to be, we hope, big plants by the time they’ve finished.

Don’t be tempted to skimp on space with this vegetable. I aim to put them two feet apart in all directions.

You could get away with 18 inches, but I reckon it’s a false economy because they grow so much better with plenty of room.

Pigeons and butterflies are troublesome, but both can be excluded by covering the plants in netting or fleece throughout their lives.

Next spring, pick the big spears first, and this will stimulate the growth of multiple smaller ones.