Globe Artichoke - cynara cardunculus is a short lived perennial vegetable that is not fully hardy, and should be given winter protection.
They can reach a height of 1.5 metres (5ft) and should be sheltered from strong winds.
They are best grown in a sunny position, on well drained soil that is kept moist in the summer, and dry in the winter.
It is better to replace them every three years, as the older plants get, the fewer flowers they produce.
For this reason it is advisable that they be grown in a relatively permanent bed to allow them to establish themselves.
They require regular watering and nitrogen feeds during the growing season.
Plants can be grown from seed, but the best way to propagate artichokes, is from offsets.
Expect only relatively small heads in a plants first year.
Allow only four to six heads to develop on each new plant, and remove unwanted buds from lateral shoots.
Established plants can produce twenty to thirty heads each season.
Harvest the artichoke flower heads when they have reached a good size and before they open.
They should be green and tight with fleshy outer scales.
Once the flower heads start to turn purple and scales start to open they become inedible.
Cut off the main head, known as the King's head at the end of each stem first.
Cut the stem halfway back at the same time.
Secondary growths may then develop, each of which will produce another tender flower head about the size of a cricket ball.
Globe artichokes are best cut one hour before cooking.
Sow seed in trays of seed compost maintain a minimum temperature of 16 C (60F).
Germination should take about 7-10 days.
Prick out if large enough to handle into 75mm (3") pots of potting compost a place in a cool frost free place until planting out time.
Remove any insulation materials around mid-April (Week 15/16) subject to weather.
Plant out the rooted suckers and new seedlings 900mm (36") between plants and a similar distance between rows, in a sheltered, sunny position,where the soil is fertile and well-drained.
Plant them at the same depth as they were in the pot or nursery bed.
Around Week 26>
The edible flower heads should be removed while still at the bud stage.
The edible parts of the flower head are the fleshy base of each scale and the artichoke heart, which is the bottom of the flower and has a better flavour.
After harvesting, cut down the foliage (around Week 28-30) to promote new growth.
Remove the 200mm (8") long suckers, or side-growths, and pot up into 100-125mm (4"-5") pots of potting compost and over winter in a frost free greenhouse or frame.
Ensure that you cut vertically so as to keep a piece of the old rootstock at the base.
Cut the stems down of one and two year old plants* to about 500mm (18") high.
Draw soil up to the stems and cover the area with a 300mm (12") layer of straw or bracken, do not cover the top of the ridges.
Alternatively, use the foliage and additional straw or bracken to protect the crowns from frost.
*Discard three year old plants, having detached the long suckers for propagation.
Prepare a sunny site that is protected from strong winds.
Deeply dig and manure a piece of well-drained ground now in preparation for planting next year.