Forcing Seakale (Crambe maritima)
Seakale (Crambe maritima)
This plant, which is found wild in maritime districts of Europe, is grown for the blanched shoots which are produced in heat and darkness during winter and spring. A batch of plants is raised initially by sowing seed out of doors in mid-spring in deeply dug enriched with manure. Seed is sown thinly in drills 2.5cm (lin) deep and 30m (12in) apart and seedlings thinned to 15m (6in) apart. Plants are kept well hoed and free from weeds and left undisturbed until the following late winter or early spring, when they are lifted and planted about 75cm (2-1/2ft) apart each way in a well-prepared site. The plants are prevented from forming a flowering stem by cutting off the crown of each plant when planting just below soil level. The plants are restricted to one stem and the foliage allowed to die down before lifting for forcing in the autumn.
When lifting plants for forcing, trim off all but the central root and pack closely, either in soil under the staging or in boxes of good soil. If given a temperature of 7-10°C (45-50°F), plenty of water and complete darkness, succulent blanched shoots will be produced.
The side shoots or root cuttings are stored in batches for planting the following late winter or early spring, it being important to make a straight cut at the top and a slanting cut at the base. They are set out vertically in well prepared soil in dibber holes 38-45 cm (15-18in) apart in rows 60cm (2ft) apart with the top (straight cut) of the cutting just below the soil surface, again limiting each plant to one strong shoot. These plants will provide a supply of forcing roots, the same rotation as previously described being carried out in the autumn.
The blanched shoots are ready for use when 15cm (6in) or so long. Once the roots have been forced they are destroyed after removing any suitably sized sections of root to reserve as a further source of cuttings.
Plant the thongs 1 ft. apart in rows l-3/4 ft. apart. Make a hole with the dibber so that when the thong is dropped into the hole the top will be l in. below the surface of the ground. Firm well afterwards.
Hoe lightly among the plants in the summer and cut off any flower heads as soon as they appear. During the third week of October cut the foliage down to soil level if it has not already died down.
Propagation is by root cuttings. Cut off straight, 6-in. long side growths, called thongs, from the established roots in November. Trim the thongs, making the tops square and the bottoms slanting so as to remember which is the right way up. Tie them into bunches of a dozen, stand them upright in the lee of a greenhouse and cover them with soil or fine ashes 1 ft. deep. By the early part of the following March the top of each thong will have developed a number of buds. Leave only one or two buds on each thong that is to be planted.
Lily White, pure white when forced. Highly flavoured and a heavy cropper.