Rotating tomatoes in each year’s garden essential
Q uestion: I’m growing tomatoes in my garden. Is it good to move them to a different location every year ? If so, why?
Answer: The term “crop rotation” might seem a bit intimidating at first, but it’s really nothing more than the thoughtful positioning of plants within the garden to ensure the same plant (or family of plants) isn’t placed in the same spot from year to year. Yes, it does require a little forethought and planning, but it’s an essential step in a healthy vegetable garden, even when you’re growing on a small scale.
Crop rotation is important for several different reasons.
1. There are many plant diseases, both fungal and bacterial, that live in the soil. If you plant a crop in the exact same spot from one year to the next, disease pressure builds up and you fall into a vicious cycle of disease. Tomatoes are particularly prone to septoria leaf spot and early blight, two fungal diseases that can easily survive the winter in the soil. By moving your tomatoes to a new location in the garden each year, you’re hedging your bets. There’s never a guarantee that your plants won’t develop these diseases in their new location because there are many other factors involved, but you are reducing their risk by taking them out of that disease-prone area.
2. Soil health is another good reason to practice crop rotation. Certain types of plants in the vegetable garden utilize specific plant nutrients, and if you plant them in the same location every year, the soil can become depleted. Root crops, for example, use a lot of phosphorous in their development, so continually planting a root crop in the same site can lead to nutritional issues and smaller-than-normal root size. Yes, fertilizers can help overcome this, but rotating your crops is a more natural way to prevent nutrient depletion without relying on fertilizer inputs. Another example is corn, which is a high nitrogen feeder. To prevent nitrogen depletion in your soil, rotate corn crops with a planting of a nitrogen-rich legume, such as peas or beans, to help replenish the soil of this essential nutrient.
3. A third reason to rotate your crops is garden pests. While some pests spend the winter as adults in weedy areas around the garden, others take shelter in plant debris left in the garden itself, or they spend the winter as a pupa nestled safely underground. Pests like flea beetles, squash vine borers, and cabbageworms, overwinter in this way. When spring arrives, they emerge from pupation and go on to breed and feed in the garden. When we rotate our crops, we move their favorite host plants away from the area where they’re overwintering and put them somewhere else, where it may be harder for the pests to discover them. Crop rotation won’t rid your garden of pests completely, but it is a big step in helping to reduce pest pressure. Some pests don’t move very far so crop rotation is useful even if it’s only on a small scale.
Plant your tomatoes in a new garden location each year, if possible, rotating them with other crops in the process. In my own garden, I have a four-year rotation cycle set up. Only every four years are the tomatoes planted in the same spot. While I do have some issues with early blight during very wet years, for the most part, my tomatoes show very limited signs of disease thanks in part to crop rotation.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to firstname.lastname@example.org or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.