Anna Pavord: 'Globe and Jerusalem - both artichokes but completely different vegetables'

While the globe is all drama and delight, the Jerusalem is neither an artichoke, nor from Jerusalem. Go figure, says our gardening expert

It's odd that the same name, artichoke, should have been given to two such completely different vegetables. The globe artichoke looks as though it has been sculpted by the builders of the Parthenon; the Jerusalem artichoke has no drama at all. Of the one, we eat the flower buds; of the other, a knobbly underground tuber. They taste entirely different, too. I won't go into the after-effects.

The globe artichoke has all the dramatic credentials to be the star and centrepiece of a vegetable plot. It has superb foliage, greyish-green and jagged, and the flower buds are held showily on fat, sturdy stems. But it is an all-or-nothing plant. It looks stunning from late May to October when it spreads at least 130cm/4ft in all directions. When the first frosts come, it is sheared down to the ground, leaving a big gap where your centrepiece once was. Unfortunately it is not a reliably hardy plant either; the combination of cold and wet during winter may cause plants to rot away entirely. In that case you will have to plant fresh offsets in late spring.

Seed-raised plants are variable, so globe artichokes are generally grown from rooted offsets, propagated from types which are known to have the best-tasting flower buds. If you have room for more than one plant, you can extend the cropping season by planting beautiful 'Violetta di Chiogga', sometimes ready in early June, along with 'Green Globe' which has a flattish, rounded head with blunt-ended scales or purplish 'Romanesco', both of which crop in July. 'Vert de Laon' is one of the many French varieties that is grown in vast quantities in Brittany and it's my own favourite, cropping midway between the others with a big fleshy heart and a superb flavour. If you leave the buds too long, they open into spectacular great thistle heads of bluish-purple, that dry well for winter flower arrangements.

In the great artichoke growing areas of France (Brittany) and Italy (the coastal plain around Brindisi), the soil is light and the climate mild. We can't do much about the climate in Britain but if you have heavy soil, you can at least dig in grit to improve drainage. Then a cold winter will be less likely to rot the plants. Only in very hot countries will globe artichokes tolerate shade. With us they should have sun.

If you are starting from scratch, set out young offsets about 130cm/4ft apart in late spring and keep them well watered until they are established. Plant shallowly, burying only as much of the base as is needed to keep the plant upright. New offsets may produce small flowerheads late in the season of their first year. Pick these off to encourage the plant to develop more side shoots. In hard winters, protect established plants by packing them with straw or covering them with fleece. Mulch thickly with manure in spring.

Left to themselves, plants are not long lived, but you can refresh your stock by chopping away offsets (new shoots) from the edge of old clumps. They should be about 30cm/12in tall and will probably have some root already growing. Don't worry if there aren't roots. Once the offsets are planted and watered, they will quickly get established.

Depending on the season, you can expect to cut 8-10 artichokes from an established plant. Cut the terminal 'king' bud first, with a couple of inches of stem attached. The head should be large but the scales should not yet be opening away from the centre. While the artichokes are still young, the inside of the stem is very succulent. Peel back the stringy outside and nibble out the innards. There are likely to be plenty of earwigs living hidden between the scales. Before you cook them, soak the artichokes upside down in a bowl of heavily salted water. That usually dislodges them.

The Jerusalem artichoke is neither an artichoke, nor from Jerusalem. Its salient characteristic was described by the 17th-century botanist, John Goodyer, soon after the vegetable arrived in England. "In my judgement," he wrote, "which way soever they be drest and eaten they stirre and cause a filthie loathsome wind within the bodie." But they are tough, hardy plants and, like potatoes, a useful first crop to plant in rough, heavy ground, where their roots will help to break up the soil.

Being tall, sometimes topping 3m/10ft, they can make useful summer screens in a vegetable garden and will filter wind on an exposed site. Our neighbour used to grow them as a temporary hedge on his boundary with the road beyond. It was cheaper than raising up the brick wall. And in winter, when the artichokes weren't there, he scarcely noticed, because he rarely spent time in the garden then.

The Jerusalem artichoke belongs to the sunflower family and that's how it got its name: girasole is the Italian word for sunflower and somehow the word drifted to become Jerusalem instead. In some seasons, the stems are topped with yellow daisy flowers, but it's the tuber hidden underground that is the edible part. They can be very misshapen and difficult to peel, which is why I always favoured a variety called 'Fuseau'. It's less knobbly than other kinds, so you waste less when you are preparing it.

No plant could be less fussy, but the best crops come from plants that grow in rich, cool soil. Once suited, they spread rapidly. Be warned... You can plant the knobby tubers any time during spring, setting them 10-15cm/4-6in deep and at least 30cm/12in apart. In very exposed positions you might have to earth up or stake the thick stems of the artichokes to prevent them blowing over. The top growth dies back naturally in late autumn. Then you can cut the withered stalks to within a few inches of the ground.

Each plant should yield about a kilo and a half of tubers which you can leave in the ground over winter and lift as needed. They keep better in the ground than in store. Try and clear them away completely before spring or you will find the tubers sprouting where you may not want them.

Buy artichokes from W Robinson & Sons, Sunny Bank, Forton, Nr Preston, Lancs PR3 0BN. Globe artichoke 'Green Globe', 'Romanesco' and 'Violetta d'Chioggia' all £10.50 for two plants, or one of each for £15.75. Jerusalem artichoke 'Fuseau', £8 for 10 tubers. Delivery of all plants from March onwards. To order call 01524 791210, email info@mammothonion.co.uk or order online at mammothonion.co.uk

WEEKEND WORK

WHAT TO DO

* Split congested clumps of snowdrops as soon as they have finished flowering. This is a much quicker way of spreading them over a large area than waiting for them to seed themselves. Replant bulbs in clumps of just two or three bulbs. Encouraged with a handful of bonemeal in fresh ground, they will soon bulk up into eyecatching clusters.

* Evergreens work hard for their living during the cut-down days of winter. Topiary pieces made up from ivy grown over a wire frame provide a quick (and cheap) alternative to box or yew and can provide the bulk and winter furnishing that a garden needs at this time of the year. Choose small-leaved varieties such as 'Adam', 'Cockle Shell' or 'Carolina Crinkle' to clothe a frame, twining the growths through the supports, or tying in stems as they grow.

WHAT TO BUY

* Summer flowering bulbs are now on sale in garden centres and through specialist nurseries such as Avon Bulbs (avonbulbs.co.uk). Particularly mouthwatering in the Avon Bulbs catalogue is a new (2013) agapanthus called 'Alan Street' with deep indigo flowers (£7.50 each), as well as some dazzling dahlias.