Crop-rotation plan can make a good garden even better
Vegetable gardeners may have already heard of crop rotation and how important it is to the health and productivity of your garden. But when your garden is small, does crop rotation really help? Can it make a difference? The answer, of course, is yes.
When it comes to crop rotation, even little adjustments can make for big changes. Plants rely on their immediate environment to access the nutrients they require, the water they thirst for and the sun they rely on.
But, they're also at the mercy of their environment. If there are pests or diseases where they live, they're more vulnerable. It's the gardener's job to create a growing environment that provides everything plants need and to do it in a way that deters pests and pathogens.
How we care for our gardens and nurture our plants obviously influences their health and productivity, but of equal importance is introducing change in the form of crop rotation.
Even if you garden in what seems like a nutshell, crop rotation is important.
A good crop rotation plan, tailored specifically to your gardening space, does pay off. Since all the veggies you grow have different needs and preferences, a good rotation plan allows you to give them what they need without depleting the soil or encouraging pest outbreaks.
Start developing a crop rotation plan by writing down all the crops you plan to grow and decide which of these production categories they “fit” into:
1. Fruit and flower producers: Plants that produce an edible fruit or flower tend to use a lot of phosphorus and potassium in their production. They also have many similar pest and disease issues. Veggies in this category include tomato, pepper, okra, eggplant, tomatillo, broccoli and cauliflower.
2. Vine crops: These vegetables use a lot of phosphorus to produce their fruits and quite a bit of nitrogen to grow lush and green vines. Many of the same pests tend to attack them too; from cucumber beetles and squash bugs to powdery mildew. Veggies in this group include cucumber, cantaloupe, watermelon, squash, zucchini and pumpkins.
3. Root crops: All productive roots require a lot of phosphorus to grow in addition to a moderate amount of potassium to increase vigor and hardiness. Shared pests include root maggots and wire worms among others. Carrots, onions, garlic, radishes, beets, parsnips, turnips, rutabagas and potatoes are included here.
4. Legumes: This is a unique group in that these plants help replenish soil nutrients rather than deplete them. Legumes are unique in their ability to take nitrogen from the air and convert (or “fix”) it into a form that is available for plant use. The many varieties of peas and beans in this category (including shell, snap and snow peas, lima, soy, pole, green, kidney wax, and other types of beans) work to add nitrogen to the soil for later use by other plants. These plants are considered soil replenishers rather than depleters.
5. Green crops: The edible parts of these plants are their leaves. Plants use nitrogen to make foliage, so these veggies use a lot of nitrogen in their growth and also share many similar pests. Plants in this group include cabbage, kale, lettuce, chard, collards, spinach and other greens.
Other commonly used crop rotation systems rely on specific botanical plant families (i.e. the mustard family, onion family, tomato family, etc.) but they can seem overly complicated for smaller areas and may be harder to keep track of, especially for novice gardeners.
Once all the plants on your list have found their category, do a simple line drawing of the garden and write down what plant grew where last season. The goal in any crop rotation system is to wait a minimum of three years to plant a member of the same production category in that area again. For crop rotation to be successful, you need to keep track of what is planted in each area of the garden, even if it's just a few feet away from where it was the previous year. Perfection is not required, but moving things around as much as you can is always beneficial.
A good three-year crop rotation plan makes it more difficult for over-wintering pests to find their host plants when they emerge in the spring, and it suppresses soil-borne diseases, such as blights and wilts.
This type of crop rotation will benefit even the smallest garden. Clearly, the rotation movement in a 40-by-50-feet garden will be bigger than in a postage stamp-sized plot, but it is helpful nevertheless. The lesson is that you don't have to move your zucchini a half-acre away, just move them as far as you can.
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 email@example.com or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.