In the winter evenings before I planted the Tomato Envy garden for the very first time, I could commonly be found sitting on our sofa, with my laptop, planning the layout in each of my eight raised beds. My husband thought he’d lost me for good in all my garden planning obsession. But, there was a method to my madness – I wanted to plan that first year layout so that, in subsequent years, I’d be able to practice crop rotation more easily.
All crop rotation means is that the same crops, or at least the same crop families, aren’t planted year after year in the same spot. Ideally, it’s best to follow a four-year rotation where no member of the same plant family is grown in the same place for four years. In smaller gardens, like mine, that’s not always possible.
Crop rotation is extremely helpful if you’re growing organically because it will decrease the need for pesticides in your garden. Certain crop families attract specific pests. For example, potatoes attract the strikingly beautiful but deadly Colorado potato beetle. Eggplants, peppers and tomatoes are in the same family as potatoes (all are nightshades), and these beetles will happily feed on any of these plants. Many members of the cucurbit plant family such as summer squash, melons, and cucumbers are the preferred food for the striped cucumber beetle.
During the growing season, adult pests feed on their favorite plants and then overwinter in the soil around the plants as either larvae or adults. Then, they emerge in the spring to feed on your new seedlings. Crop rotation deprives these groggy spring-emerging pests of their favorite foods. The pests may find their way to the new location eventually, but crop rotation slows them considerably. Once plants are well-established, they are better able to withstand some defoliation and still produce a decent crop.
The other benefit of crop rotation is healthy soil. Different plants use up different nutrients in the soil, and some plants, like beans, add nitrogen to the soil. Planting the same plants in the same place year after year depletes key nutrients and doesn’t allow the soil a chance to recover. Think about the vast monocultures of corn that dominate areas of the Midwest – year after year they deplete nutrients leaving the farmer no option but to add copious amounts of synthetic fertilizer to the otherwise dead soil.
Crop rotation in the small garden can get tricky since there’s often not enough space for a four-year rotation. The best way to handle this is to group your crops into families – nightshades, cucurbits, beans (beans, peas, favas), brassicas (broccoli, mustards, Asian greens, cabbage, kale), carrots (carrots, parsnips, dill, parsley), and beets (beets, spinach and Swiss chard). Then, rather than focus on specific crops, focus on families.
I use the Mother Earth News Garden Planner to help me with crop rotation. If, like me, you plant multiple beds with the same crop families, try to keep them in the same general area of the garden instead of all spread out. That way, you can just move that entire patch to another area without getting too complicated. In my own garden, I grow lots of cucurbits and they are planted in three of my eight beds. I keep them all on one side of the garden. The following year, I plant them on the other side of the garden so they get a two-year rotation. The best my nightshades will get is a three-year rotation because I grow two beds with tomatoes and one with peppers and eggplants.
Even if you can only alternate beds and do a two-year crop rotation, it’s better than not doing it at all. And, crop rotation is just one of many good gardening practices that build soil health and combat pests naturally to keep your garden productive and chemical-free.