Maturing of Vegetables

a way to obtain fresh vegetables in fall and winter from plants heeled in in protected soil, owing to the presence of plastic substances in tubers, hearts of cabbage heads, and succulent leaves. This method is used chiefly for cultivating cauliflower, brussels sprouts, celery, leeks, parsley, and romaine lettuce. The planting stock is grown on open ground. Brussels sprouts, celery, parsley, and leeks are sown at the normal time, cauliflower 100-110 days before the plants are heeled in (onset of hard frosts), and romaine lettuce 60-70 days before the heeling in. During this time cauliflower should form heads 2-4 cm in diameter. The soil is soaked before the plants are heeled in, and furrows 10-12 cm deep are dug in which the plants are set close together and their roots covered with soil. A temperature of 2°-6°C and a relative humidity of about 80 percent are maintained. Cauliflower and brussels sprouts may be harvested in 40 to 120 days of heeling in, parsley and celery in 50 to 80 days, leeks in 50 to 150 days, and romaine lettuce in 30 to 60 days.