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Yes, you need to rotate your tomatoes. And your other vegetables, too.

by Timber Press on July 25, 2012

in Gardening

The latest Garden Problem Solver winner wondered if it was necessary to rotate her tomato plants, and if so, how often. David Deardorff and Kathryn Wadsworth were kind enough to provide the answer. You can find many more answers to everyday garden dilemmas in their books, What’s Wrong With My Plant? (And How Do I Fix It?) and What’s Wrong With My Vegetable Garden?

You need to rotate your tomato plants every growing season for three years. Rotating your crops by growing them in a different location every year for three years helps to avoid the buildup of soil-borne diseases like verticillium wilt and southern blight. It also helps you escape soil-borne pests like nematodes, wireworms, and beetle larvae. If you choose not to rotate you will, sooner or later, be fighting off problems that you will wish you had been able to avoid.

Tomatoes are subject to a number of fungus diseases which are lethal and can ruin your whole crop.

Your rotation has to include potatoes, eggplant, tomatillos, and chili and bell peppers as well as tomatoes. All of these plants are in the same family, the Solanaceae or nightshade family, and all of them are susceptible to the same pests and diseases. Keep all the nightshades in the same rotation. Any spot in your garden where you are currently growing one of the nightshades should not see another nightshade for three years.

Healthy tomatoes free of fungus infection in an organic garden are rotated annually.

In truth, this concept of keeping related vegetables in the same rotation applies to all your vegetable crops. All the cabbage relatives (broccoli, cabbage, cauliflower, kale, and many more) are susceptible to their particular suite of problems and need to be kept in the same rotation. Do the same for all the onion relatives (garlic, leeks, onions, scallions, and shallots).

Suggested three-year crop rotation:

Group 1: Nightshades tomato, potato, peppers, eggplant, tomatillo
Group 2: Cabbage Crops broccoli, Brussels sprouts, cabbage, cauliflower, kohlrabi, kale
Group 3: Onion Crops garlic, leeks, onions, scallions, shallots
Year 1 Year 2 Year 3 Year 4
Bed A Group 1 Group 2 Group 3 Repeat Year 1
Bed B Group 3 Group 1 Group 2 Repeat Year 1
Bed C Group 2 Group 3 Group 1 Repeat Year 1

 

Accomplishing this rotation scheme isn’t as hard as it may seem. A good friend of mine has his whole garden on a seven year rotation. He keeps track by keeping good notes in a garden journal. Other people make maps of their garden and keep their records on the map which shows where they grew which crop every year. And still other people, less technically minded perhaps, like to simply randomize their plantings. Randomizing your garden is much less precise than journaling or mapping and probably won’t accomplish a 100 percent rotation. But it seems to work okay for people who prefer a more creative approach to the problem.
deardorff_dDavid Deardorff, botanist and expert plant pathologist, loves to write and lecture about how to grow healthier plants. As a research biologist David has lived and gardened in many environments, from the desert southwest to the maritime northwest to the tropics. David earned his Ph.D. in botany from the University of Washington. He coordinated plant pathology research at the University of Hawaii and served as faculty advisor to the Master Gardener Program at Washington State University. He has served as Research Director at Island Biotropix, an orchid nursery and tissue culture laboratory which he co-owned with partner and co-author Kathryn Wadsworth.

wadsworth_kKathryn Wadsworth, writer, photographer, and naturalist, enjoys sharing the wonders of the natural world with others. While leading eco-tours around the world she has studied plant life and explored natural history from Australia to Alaska. In graduate school Kathryn studied film-making and communications at the University of New Mexico, where she made documentary films on a wide variety of topics ranging from the California Gray Whale to the impact of mining on the Navajo Nation. She has owned and operated a film production company, an orchid nursery, and a tissue culture laboratory.

{ 1 comment… read it below or add one }

1 Janine Taylor July 28, 2015 at 6:54 am

How far away does this rotation have to be? We are limited due to neighboring English walnut tree.

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