How to Grow Seakale
Asis perennial and is grown on a permanent bed, once you have got a bed as large as you require, there is no need to raise more plants unless you wish to establish a new bed. Nevertheless, if you do wish to increase your stock of seakale, new plants can be very easily raised from or ‘thongs’.
The normal method is to use the side roots cut off when the plants are forced indoors. Take side roots of about pencil thickness and cut them to about 15 cm (6”) long. Cut the top horizontally, but the bottom with a slanting cut so as to indicate which way up they should be planted. Then bundle the prepared rootor thongs together and store them in damp sand or until early spring. They should then be planted out in the normal way, after removing all the buds that will have developed except one. By doing this, you will get the best possible crop.
Seakale can be easily grown in containers, such as large pots or deep boxes, but they should be at least 30 cm (1”) deep, as seakale produces strong growing, deeply penetrating roots. If clay pots or boxes are used, put a layer of drainage material in the base, fill in with some good pottingor well manured garden soil, and then place a rooted crown centrally in it with the crown upright. Fill in with more growing medium until the container is full, firm it down well and make sure there is a space at the top for watering. Water and put in a shady, sheltered place until the seakale starts to grow, then give it as sunny a place as possible.
For exhibition you want stout, crisp, well-blanched heads on which the leaf blades have not developed. Timing, therefore, is all important. If you wish to be sure of cutting heads which are just at the right stage for a particular show date, force the seakale indoors in three separate batches. Aim to have the middle batch ready at the right time, the first one a week early and the third one a week late. In this way you will have a week’s leeway if your seakale blanches more quickly or more slowly than you had planned. Use medium-sized crowns for forcing as they will produce more uniform-sized heads.
Select 12 heads for the show. Cut them carefully as late as possible before the show. Carefully sponge off all soil adhering to the heads and then tie them together in a bundle. Wrap this bundle in tissue paper and put it in a polythene bag which should then be placed inside a lightproof box with a lid containing tissue paper or wood wool to protect the heads during transport. Seakale heads are delicate and look far better if given this extra protection.
The heads are best displayed nailed upright on a spiked, circular board. Knock 12 thin nails into the back of the board so that they protrude about 3 cm (1”) through the other side. Space the nails as far apart as your seakale is wide. Then decorate the edge of the board withand put the seakale heads carefully onto the nails.
Only one variety of seakale, Lily White, is generally available.
Pests and Diseases
Pests and diseases are unlikely to occur on seakale, although a number of troublesome bacterial and fungal diseases attack the roots. The final solution, if you suffer prolonged and serious attacks of any of the diseases given below, is to sterilize your soil with steam or formalin.
Club root (finger and toe): this disease is very uncommon on seakale and is only likely to be a problem on acid soils, particularly if they are badly drained. It causes the roots to swell and distort and eventually they decay with an evil smell. The foliage wilts and dies.
Little can be done to save plants once they have been attacked; they should be pulled up and burned. The disease is serious and you should not replant with seakale or with brassicas for five years. It is obviously better to prevent it.
The most important precaution is to keep the soil adequately limed and drained. In addition, you can dust the seed beds with calomel dust or dip the thongs in a thin calomel paste before.
Violet root rot: another serious root disease your seakale may suffer from is violet root rot. A purplish felt-like growth appears on the root and above-ground the foliage quickly yellows and dies. There is no cure for violet root rot. Pull up infected plants, burn them, and do not replant with susceptible plants, which include carrots,, , and asparagus, as well as seakale, for at least three years.
Soft or black rot: occasionally seakale shoots, particularly those being forced, become slimy and rot away, together with the centre of the crown. The outside of the crowns, however, may look normal. Plants growing outdoors, if infected, will show yellowing of the leaves. These are the symptoms of the bacterial disease, soft rot. If any of the roots being used for thongs show black streaks or dots internally when cut, suspect this disease. Once again, there is no cure. Remove and burn infected plants so that the disease cannot spread. Badly drained soils often encourage an attack, so also does a warm, wet summer.