History has not recorded the adventurous gourmet who discovered that the base of the flower scales of the thistle-like globe artichoke – and the base of the flowers – could be eaten. It was a fine discovery, for their delicate yet unmistakable flavour makes artichokes one of the most prized of all garden vegetables. They are not only delicious but also strikingly beautiful, their silvery grey leaves providing a perfect foil for summer flowers. For this reason, they are often grown in herbaceous borders.
Planning the crop
Globe artichoke plants will not always survive severe winters and it is best to grow them in a sheltered, sunny part of the garden in severe-winter areas. Good soil preparation is well repaid. Loosen the soil to a depth of 60 cm and work through plenty of compost and manure. These plants need excellent drainage, and loams or sandy loams are ideal. Or plant in raised beds. They are tolerant of salt sea breezes. They need a chilling period to flower well.
How many to grow: It depends on how popular artichokes are in your household – and how much space you have. Plants need to be set 1 m apart, but if space is tight, you can plant singly at the back of a herbaceous or mixed border. Globe artichokes will grow to a height of 1.2-1.5 m.
Varieties: Green Globe and Purple Globe are most widely available. Purple Globe is hardier and best in cooler areas. Now gourmet heirloom varieties are also sought. Deep purple Romagna Violet and purple-tinged Romanesco from Italy and Gros Vert de Laon from France are propagated from seed.
Artichokes will grow and flower for about six years; the heads get smaller and tougher after three or four years. Replace a few plants each year so that you always have new plants maturing and some old ones dying down. To start a crop, buy young plants or suckers in spring and plant in soil to the same depth as they were in the nursery bed or pot.
Every year, apply a liberal mulch of manure or compost in spring. During dry periods, especially when plants are growing strongly, make sure that they are well watered. The new plants will provide a few heads by late summer, particularly if well fed with manure and potash to encourage flowering. Frost protection is essential in areas with severe winters. Cut the plant back to about 30 cm above ground.
Mound soil around the plant, taking care not to cover the crown. Put a good layer of autumn leaves on top and anchor with a double layer of horticultural fleece. In the second and third years, allow each plant to develop only four to six stems. Leave the flower on the main stem – called the king head – as well as a few other flowers at the end of the lateral shoots. Remove any offshoots around the base as this will help to keep the plant productive.
Raising new plants: During spring and late autumn in mild climates, select strong shoots about 25 cm high on plants that are at least three years old. Cut vertically alongside each shoot with a spade or sharp knife, keeping part of the rootstock below. In cold areas prone to frost, pot up offshoots in containers, and plant out in their permanent positions as soon as the danger of frost has passed.
Pests and Diseases
Artichokes are generally pest-free, apart from slugs and snails in damp conditions and aphids. Major diseases are verticillium and fusarium wilt.
Harvesting and Storing
Mature plants produce ripe heads in November and December. Pick them, starting with the king head, when the bracts are still tightly wrapped. Use a sharp knife or secateurs to cut off a head with a 12 cm stem, then cut back each stem to about half its original length. The flower heads on the lateral shoots are best picked when about hen’s-egg size. Very small, young heads can be cooked and eaten whole. You can place the stems in lightly sugared water and store in the refrigerator for a few days.
Planting: late autumn or spring
Mulching: late spring to early summer
Harvesting summer: first year to fourth year
Removal of offshoots: late autumn or spring, second year onwards