One of the virtues of this is its hardiness, which makes it possible to secure supplies in winter at a time when lettuces are difficult to produce. Soil should be rich in order to ensure quick growth and tender leaves. Dung at the rate of 1 cwt. to 8 sq. yd. may be supplemented by a top dressing of superphosphate at 1 oz. per square yard just prior to sowing. During the summer one or two top dressings of nitrate of soda, Nitro-chalk, or sulphate of ammonia may be given between the rows at the rate of 1 oz. to 12 ft., but should be discontinued after August.
Seed may be sown in small quantities at intervals between April and mid-August, but it is the later sowings that are most useful. Sow thinly in drills in. deep and 1 ft. apart, and thin seedlings to 9 in. apart. The thinnings can be transplanted elsewhere, and in October it is a good plan to place some in a frame or cloche to maintain supply if the weather is severe. Blanching must be done when the plants have attained sufficient size for use. The simplest method is to cover the centre of each plant with an inverted plate or saucer and leave this undisturbed until the leaves have become white, which usually takes about six weeks.
Varieties are Moss Curled, Green Curled, and Batavian.