Gardening: A root-and-blanch operation: You need patience, energy and good soil to grow celeriac. But it is worth all the trouble, says Anna Pavord

RETRIBUTION stalks the vegetable patch. I was too proud of my parsnips last season. This year there are none despite my lavishing upon the seed all the little comforts that a parsnip could desire. Hubris reaps its just reward.

I blame the weather. No gardener wants to blame himself. Of course it was the weather. Unfortunately, the thesis is shaken by the fact that other ticklish vegetables such as celeriac and celery, which might have revolted with equal fervour against unfavourable circumstances, did not. Both grew brilliantly.

Such a statement tempts providence: next season's crop will surely be struck by lightning. There are just four fat celeriac roots left in the garden from this year's double row. You can't afford to gamble with new recipes at this stage of the game. These four will all go in a final, elegiac gratin.

For the best gratin, you need to start with a home-made tomato sauce. Two pounds of tomatoes added to two or three cloves of garlic and an onion softened in butter is the basic mix. Add salt, pepper, basil, and wine to taste. The best addition of all is chopped coppa, very much more gamey than bacon. Whizz the whole lot briefly in a liquidiser, but not so much that it loses its chunky quality.

Clean and peel the celeriac (the most difficult part). Cut it into thick dice and cook until just tender, but not soft. Butter a gratin dish and pack the celeriac in it, scattering each layer with freshly grated Parmesan and dabs of butter. Tip tomato sauce over the top and shake the dish gently so that it settles through the celeriac. Top the dish with more parmesan and then with breadcrumbs. Bake until the celeriac is heated through and the top well browned.

Celeriac, which has a long growing season, shows a marked reluctance to leave its cradle. Lifting it requires a crane rather than a fork. When I'm doing it, I feel like part of an illustration in a book of folk tales: me holding the fork under the bulbous root, a cow holding me, a sheep holding the cow, a cat the sheep and so on with a beetle at the end of the chain. Then we all fall over backwards on top of one another as the celeriac comes out of the ground.

The roots cover the whole of the lower half of the manically uneven globe and spread horizontally, like kedge anchors. Initial cleaning is best done outside rather than in, to save the precious topsoil.

If you grow a variety such as 'Iram' (Unwins 99p) you can skip the palaver of using lemon juice to stop the celeriac turning brown as you prepare it. Natural anthocyanins regulate the amount of discolouring and breeders have fiddled with the dosage in 'Iram' so that it stays white, raw or cooked.

Plants are best started off under cover and set out when frosts are over for the season. Aim to sow seed roughly 10 weeks before planting out, any time from late February to mid March, depending on local conditions. Allow at least six months, from the time of sowing, before you think of harvesting. It seems a long time, but it is worth it.

You can sow seed in modules (small pots joined in a tray) or scatter them thinly on top of a pot of compost and prick them out into trays or individual pots later on. Germination takes roughly three weeks. If you are sowing in modules, set several seeds in each one and thin out the weaker, surplus seedlings after germination. If you are pricking out into trays, give the seedlings plenty of room (about three inches each way).

By the time of planting out the baby celeriacs will be about three inches tall. Set them roughly 12-15 inches apart in rows. Do not plant them too deep. The point where the leaves join the root should be level with the surface of the soil.

By nature, these are plants of marshland. They like rich, damp soil and tolerate some shade, provided the other two conditions are met. The most critical period is the time immediately following their being set out. The whole operation should be as smooth as a butler's bicycle ride.

It is especially important during the following six weeks to keep the plants liberally supplied with water. Some old gardeners used to mulch rows with fine grass cuttings in between watering. Occasional liquid feeds help too.

As the plants grow, their celery stalk leaves splay out around them. The usual instruction is to pull the oldest leaves away from the globes, which is meant to make them swell faster. In my very rough experiment, I noticed no difference, but there is a practical advantage in taking away some of the leaves: it reduces the amount of garbage you have to deal with when you lift the plants. In this respect, celery is easier.

The intractability of celeriac, when it comes to bashing it into shape for the pot, may explain why it is not grown more. It is a posh, much selected form of smallage, Apium graveolens, a wild celery that grows in ditches and other wet places, mostly near the sea. In cultivated form it has been around since at least the 17th century. The naturalist Gilbert White tried it in his garden at Selborne in 1760. 'Bought three plants of curious celeriac from Waltham,' he wrote in his Garden Kalendar, but few of his contemporaries followed his example.

Celery, developed from the same species of wild plant as celeriac, has always been more widely grown, the traditional season stretching from September to April. Now it has no season. It is as familiar in summer salads as on winter cheeseboards.

It is not easy to grow well. Even that super-race, the head gardeners of the Victorian era, found it tricky. According to one gardener's estimate, only a quarter of the plants he raised made the final triumphant journey to the dining table. At Sandringham, the head gardener had to grow an acre of the stuff, to be sure that the Prince of Wales (later to become Edward VII) was never without.

The kitchen staff, complained Robert Fish, head gardener at Putteridge Bury Park, Bedfordshire, were as much of a menace as drought, frost and slugs. Celery 'passes through so many hands from the garden to employer,' he wrote, 'that it becomes reduced to a very little bit and is so pared and pared again that a lover of celery scarcely knows what is before him.'

These connoisseurs reckoned the red-skinned types had the nuttiest flavour, though the white had the edge in terms of appearance. Self-blanching varieties and the now-common green American types were unknown to them. The red-stalked types are still about, though rarely in shops. You must grow your own. Marshalls have one called 'Giant Red' (46p). So do Suttons (85p). Trench celery varieties do not have such poncy names as self-blanching and American types. Compare 'Giant White' (Chiltern, 77p) with 'Ivory Tower' (Suttons, 95p), 'Clayworth Pink' (Suffolk, 80p) with 'Tall Utah 5270 Triumph' (Suttons, 75p).

Much trench celery has an unbroken provenance back to the Victorian days of Robert Fish, James M'Intosh and Edward Luckhurst. It is hardier than self-blanching types (the red hardiest of all), but requires more labour.

It does best on deep, well-drained soil, rich in humus. Some vegetables put up with mediocre conditions, but not trench celery. You will get stalks that you can make soup with, but little that is succulent enough to eat raw. Sixty per cent of the celery grown for sale in this country is raised in the peatlands of the Fens.

Sow and raise plants in the same way as celeriac. Set out the seedlings 15 inches apart. You can plant them on the flat, but setting them in a trench makes watering and earthing up easier. Start blanching when the plants are about a foot high. Tie the stems up loosely with soft string and wrap them round with black polythene, leaving the leaves poking out of the top. Pull earth up around the plants as you would potatoes.

Trench celery needs a longer growing season than self-blanching. If you plant it out at the end of May, it is unlikely to be ready before November, but it will then last through to February. Keep celery away from parsnips. Celery flies and their leaf-mining larvae like them too.

Chiltern Seeds, Bortree Stile, Ulverston, Cumbria LA12 7PB (0229 581137). S E Marshall & Co, Wisbech, Cambridgeshire PE13 2RF (0945 583407). Suffolk Herbs, Monks Farm, Pantlings Lane, Kelvedon, Essex CO5 9PG (0376 572456). Suttons Seeds Ltd, Hele Road, Torquay, Devon TQ2 7QJ (0803 614455). Unwins Seeds Ltd, Histon, Cambridge CB4 4ZZ (0945 588522).