Planting: Plant directly outdoors 4 to 6 weeks before the last frost date, when soil temperatures reach 45°F. Spacing: 2 to 4 inches between plants and 18 to 48 inches between rows. Depth: 1-inch seed depth. Best Companions: Beans, carrots, celery, corn, cucumber, eggplant, pepper, radish, spinach, tomato, turnip.