8. Figure out which vegetables/varieties you would like to plan multiple plantings (succession) plantings for and be sure to order extra seeds for these varieties. Fast growing veggies that can be only harvested a limited number of times can be planted several times throughout the season. For example, lettuce can be planted every 2-3 weeks for a continual harvest. Many veggies will have one spring planting and one fall planting. These include: cabbage, broccoli, cauliflower, kale, collards, Asian cabbage, beets, carrots and turnips.