The Nearings were Living the Good Life--homesteading--long before it became fashionable, and their advice is based on 40-odd years of New England farming. Their sun-heated greenhouse, an enclosed corner of the garden, developed from a yearning for year-round fresh greens and the unexpected winter appearance of a head of lettuce from under a pile of leaves. Their much-amended 10' x 40' version is stone and cement but a wood frame can get the same results. Location is critical (the greenhouse must face south) and good drainage is essential: run-off on at least two sides. They prefer sandy loam but maintain that soil can be modified, and compost is also recommended. The Nearings--he's now 94--write with directness, assurance, and charm, and when those homegrown leeks and lettuce brighten your winter table, you'll wonder at their ingenious ground-breaking solution.