Crop Rotation and Why it’s Important to your Garden’s Health
You may know (or be able to guess) what crop rotation is just by its name. But, do you know why you should rotate your crops? I mean, isn’t that just something the “big” farmers do?
Actually, crop rotation is something every vegetable grower should have at least a basic understanding of, and you should make an attempt to do it, even in the smallest garden.
Your first question may be: Why am I even talking about this in the fall (at least for the northern hemisphere!), when most of us are digging up our gardens? Well, you may already be planning for next spring (as I am!), so this is the time to think about what you’re going to do.
So, what is crop rotation and why do you care?
What is Crop Rotation?
According to the Rodale Institute, crop rotation is “the practice of planting different crops sequentially on the same plot of land to improve soil health, optimize nutrients in the soil, and combat pest and weed pressure.”
It can be as simple as alternating growing corn and tomatoes in the same space year after year, or much more complex. For instance, growing tomatoes one year, followed by corn in the second year, peas in the third year, and salad crops in the fourth year.
So, the important question: Why go to the trouble of rotating your crops?
Why to Rotate your Crops 1: Insect Control
I’ve found insect control to be the primary reason I use crop rotation practices.
We have lots and lots (and lots!) of squash bugs in our garden, for some reason. I don’t know if it’s because of the farms around us or what, but they show up in droves the beginning of the summer and make a mess of my squash family crops by the end.
Although I’m diligent at hand picking the little buggers, there have been years where they’ve just gotten completely out of control. Three seasons ago, hubby built me a large, heavy trellis for my butternut and other large squashes, so I tried planting them there two years in a row.
By last year (year two), I had so many squash bugs I couldn’t do anything about them and they decimated my crop.
This year, I moved my zucchini, butternut (actually honeynut this year, but a very similar plant) and cucumbers to a totally different area of the garden. Yes, I had squash bugs, but in nowhere near the quantities I had before.
Why? Well, squash bugs overwinter in the soil from the previous season. When the little buggers woke up this spring, they didn’t have squash plants to eat. I had planted garlic (proven to repel many different types of bugs) and sunflowers there instead.
Although the adults can fly, completely removing the previous year’s crop gives them less chance to find shelter over the winter, and they don’t seem to find the new areas as readily in the spring. I never saw a squash bug this year until June 29th, which is quite late for me, and their numbers were low enough that just removing the eggs kept them nicely under control.
Why to Rotate your Crops 2: Disease Control
There are many different diseases that can live in soil. You may be familiar with Phytophthora, a fungal disease that attacks tomato family plants (potatoes, tomatoes, peppers, eggplant) and was responsible for the Irish Potato Famine.
If you get Phytophthora one year and try to plant any of the tomato family plants in the same area the following year, you WILL have Phytophthora. What you WON’T have is a harvest!
If you know you have a specific disease (such as Phytophthora), do some research to find out how long it is before you should plant the same family of plants in that area again. For instance, Phytophthora can survive in the soil for 3 to 4 years, so you should plan to avoid putting tomato family plants in that area for at least that long.
Even in the absence of any visible disease, rotating your crops is a good idea. There may be a very slight level of disease present that isn’t obvious, but could proliferate if given the chance the following year. As most diseases are plant family-specific, crop rotation just makes sense.
Why to Rotate Crops 3: It May Lead to Increased Yields
There is good evidence that rotating your crops can lead to getting a better harvest from them.
Really, this makes sense. Yes, crops all use the basic nutrients in the soil (nitrogen, potassium and phosphorus) to grow. But, they use these to a greater or lesser extent, depending on the crop. In addition, there are dozens of micronutrients in the soil that crops use to varying degrees as well.
If you think about it, it makes sense that growing tomatoes where peas or beans were grown the year before would help out the tomatoes. This is because peas and beans are legumes, meaning that they don’t take nitrogen from the soil, they actually add it.
If you haven’t heard of this and the other neat things that go on under the surface in your garden, you might want to check out my posts on Mycorrhizae in the Soil Part 1 and Part 2. It’s really fascinating!
Even more intriguing, though, it appears that even rotating crops that are nonlegume crops can lead to greater yields. According to this website, studies have shown that growing, for instance, corn after cotton will yield more than growing corn year after year. In fact, the effect is even greater in years of drought, where a 25% yield increase is seen (versus 10% in a “normal” year).
I saw this demonstrated in my own garden this year. I planted my tomatoes where my beans were last year, so they got a boost from the added nitrogen the beans left for them. But, it was also an extremely dry year and I had a hard time keeping up with the plants’ water needs just with my soaker hoses.
My tomato plants look terrible, BUT I’ve gotten more than 20 gallons of tomatoes out of approximately four 8-foot rows of plants, and the majority of this yield has come from just two of those rows! Crop rotation works!
What about Perennial Vegetables?
Maybe you’re like me and you also grow perennial vegetables. You may remember my post on Egyptian Walking Onions. I also grow chives, small cherry bushes and a miniature peach tree in my vegetable garden.
Obviously, these crops are not going to be rotated, but there are still a few things you can do.
Grow some type of legume close to or around your perennial crops to give them a little nitrogen boost. For instance, this year, I planted peanuts (a new experimental crop for me!) between my peach tree and my cherries. When I pull the peanuts to harvest them, I’ll likely remove the peanuts and rebury the roots to allow the surrounding perennials to get the most benefit from the nitrogen-boosting roots.
You don’t have to grow peanuts. You can grow a leguminous cover crop in the fall (or even during the summer!). Something like clover or hairy vetch won’t interfere with your larger perennial fruits or veggies, and will enrich your soil nicely. They also have the advantage of bringing in the bees for pollination purposes.
I’m also careful to grow lots of different plants around my perennials to help with insect control. For instance, in addition to the peanuts, I also grew sunflowers in the same area and radishes under the peach tree, plus various other annuals like marigolds and some herbs.
The more diversity there is in your garden, the less you’ll have to worry about insects getting out of control. But that’s a different post for another day! *wink*
Next time, I’m going to talk about how you can create your own crop rotation plan without driving yourself nuts. If you’d like a more detailed rundown, along with more than 40 other pages of useful gardening information and places to keep all your gardening records, please check out my Garden Journal here.
I hope today’s post has been helpful and has convinced you that crop rotation is the way to go! I’ve got some pinnable images below. Please pin to your Gardening or Organic Gardening boards for future reference.
Otherwise, smile and have a crazy organic day!
Posts Related to Why Rotate your Crops
- Ultimate Garden Journal
- Mycorrhizae in the Soil Part 1
- Mycorrhizae in the Soil Part 2
- Egyptian Walking Onions
- Natural Garden Recipes