In most cold climates, start seed indoors about 8 weeks before last frost. In warmer areas (minimum winter temps above 15 F), plant outdoors in the fall to harvest the following year. Sow about 1/4 inch deep. Soil temps should be 70-80 F for good germination. Once germinated, the temperatures can be cooler, and artichoke will bud earlier if exposed to at least 8-10 days of cool temps (approx 50 F) early in its growth. However, protect from frost and freezing temperatures in your harvest year. Space plants about 2-3 feet apart. For most varieties and climates, artichokes are best when not harvested their first year. Note that the older varieties tend to have some 'wild' plants that will need to be culled out the first year.