HOW TO GROW ONIONS FROM SEED: For best results, sow seeds indoors 8-10 weeks before last heavy frost. Grow on a sunny windowsill or under plant lights. When plants are almost the thickness of a pencil, plant out in the garden. Space seedlings 2-3" apart. OR sow directly in the garden in early spring as soon as the soil can be worked. Harvest thinnings as scallions before bulbs enlarge. Dig mature bulbs when most of the tops have fallen over. Cure in a warm protected spot for 2-3 weeks. Trim tops 1 in. above bulbs. Store in airy, dry, cool, frost-free place.