They grow best in any good garden soil.
Transplant to their permanent position when they are large enough to handle, with at least five true leaves, allowing 60-90cm (2-3ft) between plants. Water in well.
Seed-grown plants usually flower the year of sowing.
To keep stock young and vigorous, divide plants every two to three years and plant at the same spacing as seeds.
Keep crops weed free, mulch with well-rotted manure or similar in spring when the soil is warm and moist. Feed with 70g per sq m of general fertiliser such as Growmore or similar in spring, to increase yields.
Water during dry weather.
In cold areas, cover plants with a mulch of straw, compost or well-rotted manure in late autumn, to protect them during cold winter weather.
Slugs and snails: These feed on the young seedlings and you'll see the tell tale slime trail on the soil around your crop, as well as on the leaves.
Remedy: There are many ways to control slugs and snails, including beer traps, sawdust or eggshell barriers and copper tape.
More info at rhs.org.uk
Aphids: Look for colonies of greenfly on the soft shoot tips of plants or on leaves. They suck sap and excrete sticky honeydew, encouraging the growth of black sooty moulds.
Remedy: Use your finger and thumb to squash aphid colonies, spray with pyrethrum, plant or fish oils or use the biological control aphidius or aphidoletes in the greenhouse.
More info at rhs.org.uk
They become more prolific each year until, after several years, they run out of steam and the planting needs to be renewed.
Remove buds – ideally when they reach the size of a golf ball - with a pair of secateurs from July, before they open and start to flower.
After harvesting the main head, secondary heads appear, these too can be harvested, when large enough.
Cooking tips: Boil or steam immature heads until tender, drain, remove the leaf scales one by one, dip them in melted butter, vinaigrette or Hollandaise sauce and then suck out the juicy flesh from each scale. Finish off with the succulent base. Mature flowers take longer to cook and are less flavoursome, but can be cooked and consumed in the same way. Delicious!
Nigel Slater adds leeks to his Artichoke soup with ginger and walnuts.
‘Vert de Laon’: Hardy with an excellent flavour.
‘Green globe’: Large green heads with thick, fleshy scales. Needs winter protection in cooler areas.
‘Purple Sicilian’: Small, deep purple buds, which are excellent for eating raw, when young. Not frost hardy.