Plant directly outdoors in spring when night temps reach 10C, or start seeds early indoors 3-4 weeks before last frost. Grow in a sunny spot in average, well-drained soil. Sow seeds 1 inch deep and 4-6 inches apart. Keep soil moist, especially during dry periods. Thin young seedlings 8-12 inches apart so they have room to mature. Nasturtiums need no added fertilizer.