The secret to growing a productive organic vegetable garden is to prevent pest and disease problems before they start. Vegetables that belong to the same plant family, such as peppers and tomatoes, share diseases and pests. Growing vegetables from the same family in the same place year after year can result in the buildup of diseases or pests in the soil. So, a basic way to avoid disease and pest problems is to practice crop rotation. By planting your plants in a different spot each year, you deny overwintering diseases and pests quick access to their favorite host plants. Here’s how to create a simple crop rotation plan for your garden.
1.Make a list of the vegetables you plan to grow in your garden and group them together by plant family. Common plant families include: the Brassicas (cabbage, broccoli, kale, cauliflower, mustard greens), Legumes (peas, beans, fava beans), Alliums (garlic, onions, shallots, chives), Solanaceous crops (tomatoes, peppers, eggplants, potatoes, tomatillos) and Cucurbits (melons, winter and summer squash, cucumbers, zucchini, pumpkins).
2.Draw a map of your vegetable garden beds on graph paper and make several copies. Use the map to plan where you will plant each crop in your garden. To simplify the crop rotation plan, it’s best to grow plants from the same family together. Be sure to note which vegetables you grew and where on the map. Also, don’t forget to label it with the year, because you will be referring back to it for at least three to five years.
3.When you begin planning your garden the following year, refer back to the map from the previous growing season(s). Rotate each plant family to a new spot in the garden. Crop rotation works best on a 3- to 5-year sequence-meaning if you planted Solanaceous crops in one spot in 2008, you wouldn’t plant them there again until 2012 at the earliest.
4.Rotating crops helps break pest and disease cycles, but it also gives you an opportunity to balance the nutrients in your soil. For instance, heavy-feeding crops like squash and tomatoes draw a lot of nutrients (especially nitrogen) out of the soil. But legumes (peas and beans) actually add nitrogen to the soil. So, a good crop rotation strategy is to plant heavy-feeding crops in a spot that legumes were growing in because the soil is richer in nitrogen. You can also recharge soil by rotating legumes into a spot that heavy feeders were growing in.