<p>65 days. Heavy, compact, extra-dark green heads, Winter Density is a butterhead/romaine cross. This unique English variety can be grown in spring, summer or fall. Good eating. Frost tolerant and quite bolt resistant.</p><p>CULTURE: Lettuce is a cool season plant and grows best in the milder spring air. Lettuce can be sown either directly into the garden, or indoors and then transplanted as soon as the garden can be prepared (April on the Coast). With a bit of planning, you can plant lettuces and greens every 1-2 weeks all summer long for a continual harvest; plus, by using a cold frame and cold-hardy varieties, you can stretch the fall growing season far into the winter months. To direct-sow, seed 2.5cm (1 in.) apart in short rows (just plant a few feet each seeding) 45cm (18 in.) apart. Cover very lightly and press down soil gently. Some varieties will germinate well at soil temperatures as low as 4 deg. C (40 deg. F). Soil temperature over 25 deg. C (80 deg. F) (July and August) can induce thermodormancy (seeds not sprouting because of the heat). To overcome this problem, soak lettuce seed for 12-16 hours in cool water overnight, then air-dry the seed on newspaper for 2 hours before sowing. As soon as 2 or 3 true leaves have formed, thin leaf types to 20cm (8 in.), and heading types to 30cm (12 in.) apart. One gram of seed can sow 10m (34 ft.) of row, so don’t plant the whole package at once! <br>To raise transplants, sow 3 or 4 seeds per 2.5cm (1 in.) in sterile seeding mix 3 weeks prior to planting out. Two weeks after sowing seed, transplant individual plants into pots or cell trays. Remember to harden off your transplants for 2 or 3 days before planting out by reducing water and setting the plants outdoors in a sheltered location. <br>Leafy green vegetables require a moderately fertile soil. They follow the root crops in a rotation and are themselves followed by the potatoes. One cup of complete organic fertilizer per 3m (10 ft) will give adequate nutrition. Since lettuce is shallow-rooted, regular attention to watering will encourage vigorous growth without the development of bitterness in the leaves. Thin loose-leaf types to 25cm (10 in.). Icebergs, Batavians, butterheads and romaines should stand 30-40cm (12-16 in.) apart for full-sized plants; closer if you will be picking individual leaves. <br>INSECTS: Aphids and slugs must be controlled to get any harvest of lettuce. One way to control slugs is to make sure that there is a clear dry patch of soil or sharp river sand between their daytime hiding places and their evening meal. Garden clean up is important to eliminate hiding places near their food. Vigorous, rapidly growing lettuce transplants will benefit from the protection of a mini-cloche (try clear 2 litre pop bottles with the label and bottom taken off). Just make sure there are no slugs in with the seedling! <br>HARVEST: During the summer, a bed of lettuce stays in prime eating condition for only 2-3 weeks, so succession plantings are the trick. Individual leaves may be picked from all except head lettuce, but this only extends the harvest somewhat because all lettuce becomes tough and bitter as bolting approaches. (Place lettuce under warm tap water to reduce bitterness.) In fall and winter the plants stay in good eating condition longer. <br>SEEDSPEC: Minimum germination standard: 70%. Days to emergence: 2-15. Optimum soil temperature range for germination: 4-21 deg. C (40-70 deg. F). Days to maturity: from date of direct seeding; subtract 10-15 days if transplanting. Approx. 500-800 seeds/g. Usual seed life: 3 years.</p><p>The many forms of lettuce is the most important salad crop, grown in almost all temperate regions of the world. All letuces were developed form the wild species Lactuca serriola found wild in clearings in woods and on rocky slopes from Asia and North Africa to northern Europe. It is an annual, germinating in autumn and forming rosettes of leaves which can be seen along roadsides as they flower in late summer, after reaching about 2m in height. the leaves are spiny and either obvate and entire, or deeply lobed, and the flowers pale yellow. <br>Lettuces were grown by the Romans, who introduced it to Britain, but are thought to have been cultivated first by the ancient Egyptians around 4500 BC. They may have been cultivated there first for the edible oil in the seeds, rather than for salad greens. Seeds were taken to America by early British settlers. Lettuces are soporific, as any reader of Beatrix Potter would know. This property has been recognised since ancient times, and is mentioned by Hippocrates in 400 BC. Until quite recently, the bitter latex was often used as a substitue for opium or laudanum. Lettuces with firm hearts are only known with certainty from the 16th century onwards. Modern breeding concentrates on resistance to disease and bolting, and also on more fancy leaf shapes and colours.</p>
