Celeriac: A celery substitute
If you like the taste of celery, but find it a difficult crop to grow, then try—an undemanding, unusual and delicious root vegetable with a celery taste.
Celeriac (Apiumgraveolens rapaceum) is a close relative of celery, but it is grown for the swollen root-like stem below ground rather than for the slender stems appearing above the. Also known as turnip-rooted celery or knob celery, celeriac is easy to grow and will thrive in most soils and situations. It is a particularly good crop if you like celery but have difficulties with the winter varieties; try a crop of celeriac to add an aroma and flavour of celery to winter soups and salads. You can also blanch the stems and eat them.
If you want to grow celeriac, choose a site in your garden which is fairly sunny and has some. Celeriac likes a reasonably rich soil, although not excessively so, and one which provides a steady supply of water; hence a slightly heavy soil will give better results for less trouble than a light one. Ideally the site should be one which had a generous application of rotted manure or garden dug in during the previous autumn. However, do not be discouraged if your soil does not meet this ideal; celeriac is quite happy in most soils so long as they are well-drained, and water can be supplied in dry weather.
Because celeriac needs quite a long growing season, six to eight months from sowing to harvesting, it is advisable to sow the seed in boxes under frames or cloches, or in a slightly heated greenhouse or propagator. This is particularly important in temperate climates, for celeriac seed will not germinate unless the soil temperature is at least 15°C (60°F), and this may not be reached until mid-spring, or later.
Sowing should take place in early spring. Fill seed trays with a good quality seed compost, and sow the seed about 2.5 cm (1”) deep. Cover lightly with soil, and place the trays either outdoors in frames or under cloches, or in a greenhouse. A little heat will help the seed to germinate quickly. You can also sow them direct into compost-filled peat pots, putting three seeds in each pot. When theare large enough to handle, just before they reach the four-leaf stage, prick them out either into boxes or singly into peat pots kept in a frame, or into the open ground, protected by cloches. Allow a spacing of about 5 cm (2”) between seedlings. Seedlings already in peat pots should be thinned to a single plant.
Whether they are in boxes or in the open ground under cloches, the seedlings will need to be hardened off during the spring. Begin by opening the frame or removing the cloches for a few hours at mid-day on sunny days. Gradually lengthen this period until it is warm enough and the seedlings are strong enough to dispense with protection.
The young plants will be ready for transplanting to the permanent bed in late spring, when there will already be a slight swelling of the root. Put the plants in rows spaced 30-38 cm (12-15”) apart; space the plants 30 cm (1’) apart in the rows. Be sure to handle the plants very carefully and to avoid damaging the swelling root, which should be placed level with the soil surface, rather than below it. Celeriac requires little care and cultivation during the growing period. Just after transplanting, water the young plants thoroughly, and be sure that they have enough water if the weather is dry during the main growing period, otherwise the root will not swell to its full size.
Apart from watering, the only care necessary during the summer growth period is. Use a hoe to keep the bed weed free, and be careful about weeding close to the plants, so as to avoid damage to them at soil level. If you would like extra-large roots, regular liquid feeding from mid-summer to early autumn will help. Towards the end of late summer, side-shoots will start to sprout from the crown; these should be removed. At the same time, scrape away the soil around the root so that at least half of it is exposed.
Later, celeriac should be earthed-up to protect it from frost and to keep it from being bitter-tasting. Do this in mid-autumn, or earlier if frosts threaten. Draw up soil to cover the root completely and at least 5 cm (2”) of the stems. If you want to blanch the young stems as well, do this at the same time by wrapping sheets of black polythene around the stems, leaving a bit of leaf exposed at the top, then earth-up the entire length of the stems.
Blanched stems should be ready for cutting in late autumn. You can lift the roots as required from mid-autumn onwards. Celeriac will tolerate moderate frost, and can be left in the ground through the winter.
However, if heavy or prolonged frosts are predicted, or if you live in an area where the winters are always severe, you would do better to lift the entire crop at the end of autumn and store it in boxes of dry sand, peat or soil, and remove all the leaves but the small ones in the centre. If the boxes are kept in a dry, frost-proof place, you should be able to enjoy celeriac during the winter and into early spring.
There is very little aftercare required from a crop of celeriac. If you choose not to eat the stems, consign them to the compost heap, if they are free of pests; otherwise, put them on the bonfire.