Crop Rotation: It’s Not Just for Farmers

Planning on organizing your garden the same way next year? Think again! Growing your vegetables in the same location every year depletes your soil of certain nutrients, opens the door for soil-borne diseases and results in the need to invest in expensive fertilizers each year. Repeated planting also makes it easier for pests who have overwintered in the soil to affect your young plants, costing you even more money on pesticides. So instead, try crop rotation! Crop rotation is a simple concept, all you are doing is planting your vegetables in different locations within your garden each year.

But does it matter what order you do it in? What if you’ve been rotating your vegetable crops but are still having poor results? Vegetables vary in their nutrient requirements, and some actually add nutrients into the soil. It’s also important to understand which botanical family your vegetables belong to. For example, plants in the legume family produce nodules on their roots which take nitrogen from the atmosphere and convert it into a plant friendly form. Some common legumes are beans, peas, soy beans, and peanuts. Whereas, plants that fall in the brassica or greens category require lots of nitrogen to grow; like lettuce, spinach, kale, and broccoli. These vegetables will grow better if you plant them in a spot that grew legumes the previous year.

What about tomatoes, melons, and cucumbers? These fruiting vegetables need less nitrogen, so they grow great if they are planted after brassica or greens. Lastly, root vegetables like carrots, onions, radishes, and beets require less nitrogen, but high amounts of potassium. So typically root vegetables are planted at the end of the rotation to pull the last of the nutrients out of the soil before it is rejuvenated by legumes in the following year.

Image: A complex break-down of commonly planted garden vegetables and their botanical families.

Botanical families are also important to consider when it comes to weed control. This is an element of crop rotation that is often overlooked. Many common weeds fall under the same botanical families as your crops. These weeds can be carriers of diseases or pests that can attack your young plants, putting your efforts to waste, and using up the valuable nutrients in your soil.

An ideal crop rotation should fall on a 3–4-year rotation for small crop gardens. A five-year rotation would be even better and can be implemented by introducing a fallow bed. If space allows, a fallow bed is a patch of your garden that is unplanted and lets the soil rest and refuel. For gardens that don’t have space to introduce a fallow bed a common cycle is demonstrated by the graphic below.

Image: A simplified 4 year vegetable crop rotation guideline.

Of course, this is merely a simplified guideline and can be broken down even further by separating botanical families into smaller groupings, or planting with consideration to early and late season crops grouped together. For example, if you planted lettuce with tomatoes one season you can follow next year by planting that section with collards and pumpkins.

So how do you get started? Section your available garden space to avoid overlap and keep detailed records of where you’ve grown crops previously by making use of a garden journal. This will help you better plan where to plant the next year. If you’re not sure which part of the cycle your soil is ready for, soil testing is a quick and easy way to assess your soil’s health before planning your crop rotation. We offer a wide variety of soil testing packages to suit any grower’s budget. You can take a look at our packages here.

Don’t dismiss your irrigation water either! The water you use to hydrate your plants is just as important as the soil you plant them in. We also offer water testing for all sorts of purposes, even greenhouse irrigation. You can find our irrigation water test packages here.

Sources:

“Crop Rotation Made Easy” By Jenny Peterson
https://bonnieplants.com/blogs/garden-fundamentals/crop-rotation-made-easy#:~:text=One%20approach%20to%20crop%20rotation,each%20group%20one%20spot%20clockwise.

“Rotating Your Vegetables” From University of Saskatchewan College of Agriculture and Bioresources
https://gardening.usask.ca/articles-and-lists/articles-how-to/rotating-your-vegetables.php

“Crop Rotation in the Vegetable Garden” By Aaron Steil, Consumer Horticulture Extension Specialist, Iowa State University
https://hortnews.extension.iastate.edu/crop-rotation-vegetable-garden