Benefits of Crop Rotation for Gardeners: Maximizing Yield and Soil Health

Here’s a subject that makes me spin with joy: crop rotation.

It doesn’t sound all that exciting, but if you love your fruits and vegetables, it’s the bomb! It’s the way that I – and countless other gardeners and farmers – make sure the soil stays fertile and help protect my plants from disease and insects.

The simple version: Crop rotation involves moving the area where you plant your crops. One year, I’ll plant tomatoes in garden bed one, next year I’ll plant them in garden bed 12. One year, I’ll plant my squash in bed 10, the next year I’ll plant it in bed 2.

The same goes for planting in fields. Experienced gardeners move their plants and vegetables from field to field.

Why do all this extra work? After all, you have to come up with a garden plan every year, so why come up with more than one plan? Why not just pick where your vegetables are going to grow and stick with it?

Here’s why. If you do that, your first year of gardening may be glorious, your second year may or may not be decent, but you will quickly see your crop yield shrinking, your fruits and vegetables getting smaller, and diseases and fungus and pests moving in and destroying all of your hard work.

Unfortunately, when the same crop is planted year after year, the soil becomes depleted of the nutrients that are needed by that specific fruit or vegetable. And then, in a double whammy, the diseases and fungus and pests that love a specific type of meal – say, squash vine borers – find where you’ve planted their favorite food. And they settle in, and eat your food. And they call all of their friends and family and ask them to move in.

When gardeners move the crops, they disrupt the life cycle of pests and diseases, and replenish the soil with the nutrients needed for the next crop to thrive.

Crop Rotation For Soil Nutrition

Crop rotation helps to prevent the depletion of soil nutrients by alternating crops that have different nutrient requirements. For example, legumes such as peas and beans are nitrogen-fixing crops that add nitrogen to the soil, while brassicas such as broccoli and cabbage are heavy feeders that require a lot of nitrogen. By rotating these crops, the soil remains fertile and rich in nutrients.

Historical Background

Like all good farming and gardening methods, such as the Three Sisters Method, crop rotation has been practiced for thousands of years.

Evidence of crop rotation stretches back to ancient civilizations including the Greeks and Romans. In the Middle Ages, farmers in Europe used a three-field system of crop rotation. They divided their land into three fields. They would plant wheat or rye in one field. They would plant barley, oats, peas, lentils or beans in the second field. The third field was left fallow – empty. Each year, they would rotate the crops through the fields.

This system helped to improve soil fertility and increase crop yields at a time when agriculture was the primary economic driver. In turn, this lead to increased economic stability, and a population boom. Less people starving, and more food available, is always a good thing in my book.

Because it works so well, crop rotation is still widely used by farmers and gardeners everywhere, especially those who love organic practices and green gardening. Hey, when something works, it works!

Reduction in Fertilizer Use – Huzzah!

Using fertilizer costs time and money, but it can’t be completely avoided. Crops are heavy feeders and by the end of the growing season, they’ve depleted the soil of nutrients.

Some crops, however, return certain types of nutrition, like nitrogen, to the soil. So with crop rotation, you’d plant a nitrogen-fixing plant in a specific area one year, and a nitrogen-feeder in that area the next year. Instead of purchasing a fertilizer with nitrogen, gardeners can let their plants do a lot of the heavy lifting.

This saves money on fertilizers and also, to the delight of us tree-hugging types, it reduces the fertilizers environmental impact. Even natural fertilizers can have a detrimental impact on the environment in numerous ways, especially through the runoff into local bodies of water, and soaking into groundwater. Fertilizers in groundwater and lakes and ponds can cause excessive growth of algae and disrupt the local ecosystem. The less fertilizer used, the less effect on the environment.

Pest and Disease Mitigation

Potato bugs love my potatoes. Squash vine borers love my squash.

I hate potato bugs and squash vine borers with a fiery burning passion.

Ditto, the Bacterial wilt or Southern bacterial blight that loves to plague my tomatoes. Unfortunately, the Ralstonia solanacearum, the bacterium that turns my plant stems to mush, gets into the soil and lasts there for a long time. So what to do?

Move the crops, of course. Hide them from the pests that want to destroy them.

By alternating crops, gardeners can disrupt the life cycle of pests and diseases that love to make gardeners and farmers cry. Or maybe that’s just me. Now, in some cases, like the tomato blight, it can take several years to eliminate it. There’s a lot of planning that goes into crop rotation, but it’s worth it in the end.

By disrupting the life cycle of pests, gardeners can reduce the number of pests in the garden. This means less pesticide use. Even the friendliest pest control methods can also harm our beneficial pollinator friends. For instance, a pesticide that targets bad caterpillars, like bollworm, can also kill good caterpillars, like those that produce butterflies. Therefore, any method that reduces the need to use even the most organic of pesticides, is beneficial to the environment. It’s always better to work with nature when possible.

Crop Rotation Practices

Choosing the Right Crops

So what are some examples of specific crops to rotate, and in what order? I’m so glad you asked. (OK, I asked myself, for the purposes of this article, but I know you were thinking it!)

A perfect example of picking the right crops to ensure soil fertility is the use of legumes like beans and peas one year, and the use of broccoli or cabbage the next year. Legumes fix nitrogen in the soil, while brassicas like broccoli and cabbage deplete soil of nitrogen. It’s common practice to rotate these two crops to take advantage of each type of plants’ natural properties.

Another factor to consider when rotating crops is disease susceptibility. Some plants are more susceptible to certain diseases than others. By rotating crops, gardeners and farmers can reduce the buildup of soil-borne pathogens. For example, tomatoes are susceptible to verticillium wilt, while corn is not. It’s all fun and games until your tomatoes start to wilt. So by rotating these two specific crops, gardeners can reduce the incidence of verticillium wilt in their tomato plants.

It’s important to know what plant families are susceptible to what diseases. For instance, garlic is susceptible to certain funguses, and wheat and barley are susceptible to the same funguses. So, you would not want to follow a planting of garlic one year with a planting of wheat or barley in the same bed or field the next year.

Strawberries are also susceptible to verticillium wilt, so you would not want to follow tomatoes with strawberries, or vice versa.

Onions are susceptible to a fungus called pink root. Moving them to different spots every year can prevent this.

The Department of Agriculture has some great tips on specific examples of crop rotation!

Rotation Scheduling

So, how frequently should you rotate your crops? When can the tomatoes and garlic return their original home?

The most commonly recommended cycles are three years or four years, which can vary depending on the number and type of crops that you have, and the space available to you, and what your gardening goals are.

In the most common practices of the three year cycle, crops are generally divided into three groups: legumes, brassicas, and all other crops. In the first year, legumes are planted, followed by brassicas in the second year, and all other crops in the third year. Legumes include lentils, broad beans, peas, chickpeas, peanuts, and soybeans. Brassicas include broccoli, cabbage, Brussel sprouts, radish, and kale.

Four Year Crop Rotation

There are different versions of the four year crop rotation schedule, depending, again, on your gardening goals and needs.

The four year crop rotation dates back to Belgium, in the 1600s. It was popularized by a British agriculturalist named Charles Townsend in the late 1600s and early 1700s. It consisted of growing wheat, turnips, barley and then clover, and it was designed to provide food for livestock year-round. Turnips are a fodder crop, and they were used for feeding livestock in the winter. Clover is a grazing crop. This lead to not just better crop yield, but also an increase in the number of livestock, and therefore valuable manure for fertilizer.

Of course, not everyone has livestock or needs to feed livestock. For those who don’t need to grow fodder crops, there are other methods of the four year system. Many farmers rotate potatoes, then legumes, then brassicas, then legumes, throughout their fields. The longer rotation period can be beneficial, giving more time for pathogens and pests to die. Die, pests, die. I’m looking at you, potato bugs.

Crop Selection Limitations

Not every crop can, or needs to, be rotated. Some plants and fruits are not suitable for rotation due to their specific growth requirements. For instance, mint does not need to be rotated. Asparagus takes several years to be established and should not be rotated.

In the beginning, before planting, gardeners and farmers need to do their research, considering their climate, the size of their garden, and the crops that they want to grow. It sounds like a lot of work, but if you establish a plan in the beginning it only needs to be done once, and you will reap the benefits for the entire life of your garden!