Thursday, April 16, 2020

What is crop rotation by Vicky Spelman

Courtesy Wisconsin Horticultural Division of Extension
Crop rotation is one of agriculture’s oldest beneficial practices.  In the home vegetable garden, crop rotation involves changing the planting location of vegetables each season within the garden.  It is used to reduce damage from insect pests, to limit the development of vegetable diseases, and to manage the soil fertility.


Should you rotate the crops in your garden?

Generally, it is not recommended that an area be planted with plants of the same family in succession to avoid the buildup of shared pests.  

So, while you’re waiting for winter’s snow to give way to spring planting, why not start planning this year’s vegetable garden giving thought to what you grew where last year.
Courtesy Pixabay
When vegetables classified in the same plant family are grown year after year in the same area of a garden, they provide insect pests with a reliable food source and disease-causing organisms (i.e., pathogens) with a continual source of host plants that they can infect.  Over time, insect pest and pathogen numbers build in the area and damage to your vegetable crops increases.  Using crop rotation helps keep insect pest and pathogen numbers at low levels. 

For example, if tomatoes are planted in a bed or area of a garden one year, vegetable crops such as peppers, eggplant, potatoes and tomatoes should not be planted in the same bed or area the following year because all of these plants belong to the nightshade family (Solanacaeae). Typically, root crops are followed by legumes, which precede leafy crops, which precede fruiting crops.  

See the chart below to assist you in determining your crop families.

 Common Vegetables and their Plant Family Classifications:
Courtesy Wisconsin Horticulture Division of Extension 

Each vegetable is unique in the type and amount of nutrients it extracts from the soil. By rotating the types of vegetables within a garden area over one or more years, you can build back the nutrients that may have been depleted from one type of crop.  It can also continue to improve the air capacity and water holding ability in the soil.  Grass clippings and leaves also help to add nutrients to your soil and reduce moisture loss.

Sources for this article:  Rotation, Crops, Gardening