Direct sow beginning 2-3 weeks before last frost, or start indoors 3 weeks earlier and transplant. In-row spacing should be 12 inches apart (thinning makes great braised greens!). Harvest outer leaves for continual production. One sowing will provide harvestable greens all season, though it's smart to do a mid-summer sowing in case disease pops up. Sowing monthly in succession would provide a steady crop of the most tender, young leaves. Like all plants harvested for their leaves, chard appreciates fertile soil.