HOME GROWN:IF YOU ARE a gardener with a capacious country plot or with an allotment, I envy you. You have plenty of room for perennial vegetables. Most of these – artichokes, asparagus and seakale, for example – take up a disproportionate amount of ground area in return for their yield, but if you have space to spare, they're worthwhile crops to grow.

They are the kind of thing you rarely find in the shops, or if you do, there is only a slim chance that they are fresh and local.

With perennial crops, the plants are going to be in place for a few years (asparagus beds can last for 20 or more years), so the initial ground preparation is tremendously important. Dig out all weeds, and when you have done that, add plenty of organic matter to the soil: garden compost or well-rotted manure.

After you’ve put your plants into the ground, you will probably need to water them well to settle them in, and to provide a reservoir of moisture to help them get established. You may need to water again during dry periods in the first season of growth. I don’t like to over-use water in the garden, but it is a false economy to be miserly when plants are making formative growth. If you have heavy, clay soil, however, go easy on the irrigation, as too much can lead to rot.

All four of these perennial crops may be planted now, or in the coming weeks.

Globe artichokes

Pick a sunny spot with good, free-draining soil. Don’t let any flowers form in the first year, as they take energy away from the plant. In subsequent years, if you want to harvest large artichokes, nip out the side flower buds and leave only the central one on each plant. The yield tends to tail off after a few years, so be prepared to start new plants from the basal shoots.

Asparagus

This needs light to normal soil in sun. Choose male cultivars (Gijnlim F1 and Theilim, for example), as they produce more shoots. Don’t harvest any spears in the first year. In the following years, harvest for no longer than six weeks. If spring is dry, water the ground well, so that the shoots are plump and prolific. The ferny stems that grow after you finish harvesting feed the roots for next year’s crop, so leave them standing until they go brown in autumn. They may need some support to stop from toppling over.

Rhubarb

Use a sunny spot, with lots of well-rotted manure or organic matter. Add grit if the soil has a high proportion of clay. Plant dormant crowns in autumn, or potted plants in spring or autumn. The fleshy crowns can rot in heavy soil if planted too deeply. Don’t remove any stalks during the first year.

In following years, always leave half of the stems to regenerate the crown. Rhubarb is a herbaceous perennial, so the plant gets less productive in the centre as it ages. It should be divided every few years.

Seakale

Use full sun, and light, sandy soil – it is a maritime plant, and is not happy in heavy clay. The young stems must be blanched to make them tender and edible. To do this, cover the plants with special seakale forcers (or with any light-proof container such as a large black bucket), before the shoots emerge in late winter or early spring. When the new growth is about 25 to 30 centimetres long, cut the stems at the base.

Cook seakale in the same way as asparagus: boil or steam it, and leave it al dente. Allow the next lot of leaves to develop naturally, so that the plant recovers. If you are serious about eating seakale, you won’t let the plants flower, as this expends energy and reduces next year’s crop of leaves. The flowers, however, are beautifully honey-scented, and an interesting addition to fruit salads.

Perennial crops in small gardens

In a small garden, ground area might be too valuable to give up to space hogs such as the above plants. This is where dainty individuals such as wild rocket (Diplotaxis sp.) and sorrel come in. These salad plants (the first is hot and peppery, the second, sharply sour) usually survive several years – although last winter will have caused some to breathe their last.

Both can be grown from seed: look out for red-veined sorrel and buckler sorrel, for something different. Eat only the young leaves, as the mature ones are unpalatable. When established plants get scraggly, shear them back to the base to promote a fresh flush of tender new

Diary date

The next gardening weekend with Ciaran Burke at Connemara’s Cashel House Hotel is April 10th-11th (arrive on the evening of April 9th), and the theme is The Fruit Garden – Planning and Pruning. Further weekends take place a fortnight later (Propagation Workshop), mid-May (Summer Colour) and in June, July and September. Prices from €285 (April) and €300 (other months) per person. Tel: 095-31001, cashel-house-hotel.com