Start indoors mid spring for early fall harvest, late spring for fall harvest. Sow seeds in pots, 2-3 per cell, about 1/2 inch deep. Once the seeds have sprouted, thin the smallest, weakest plants to 1 per cell. Transplant outdoors once the seedlings have 2 sets of "true" leaves, 24 inches apart. Brussels sprouts take 100 days from transplant. Be sure to give them adequate water and replenish the soil by side dressing with good compost or other balanced organic fertilizers at least 2-3 times through the season. Brussels sprouts are very cold hearty, and can be left out and harvested late fall.