Crop Rotation
Crop rotation is a pest and disease prevention strategy that involves rotating the planting of families of crops–each with different nutritional needs–in succession in the same space. This fact sheet provides information on adapting crop rotation techniques to fit urban agricultural systems.
Crop Rotation
If you plant your tomatoes in the same bed every year, pests and diseases will build up in that soil and eventually cause crop failure. Crop rotation involves moving the location of each “family” of crops (i.e. the squash family, tomato family, cabbage family, etc) every year so that they don’t return to the same place for 3+ growing seasons. Urban farmers can use crop rotation to maximize productivity and simultaneously improve soil fertility, as well as to help protect against plant diseases and pest infestation.
A sample crop rotation, as suggested by Thomas J. Fox in Urban Farming: Sustainable City Living in Your Backyard, in Your Community, and in the World (Hobby Farm Press, 2011), might be:
- Follow a heavy feeder (such as fruiting crops) with a light feeder (such as root vegetable crops);
- Follow a light feeder with a nitrogen fixer you plan to eat (such as peas);
- Follow a nitrogen fixer you plan to eat with a nitrogen-fixing cover crop (see below, Factsheet #22)
- Return to the beginning and plant a heavy feeder.
In a single planting bed over 4 years, one specific example of the above plan might look like:
- Yr 1 – squash family (pumpkin, melon, zucchini, winter squash)
- Yr 2 – carrot family (carrot, celery, cilantro, parsley)
- Yr 3 – pea family (peas, pole beans, bush beans, edamame, fava beans)
- Yr 4 – squash family again
Because urban farmers traditionally have small land bases, however, crop rotation can be difficult, and requires careful and detailed planning. To start, make a list of all the crops you intend to grow, and group them by their botanical family. If this is your first year growing in a space, you can plant each crop wherever you have space. In subsequent years, you’ll need to map out which crops can go in each area based on what grew there the previous year. It’s a bit like putting together a puzzle. Over time it gets easier as you develop patterns, like you always follow corn with beets, and beets with edamame, for example.
For more information on crop rotation, see:
The Farmers’ Almanac provides more detailed guidance and a handy chart.
Crop Rotation on Organic Farms: A Planning Manual, a Natural Resource, Agriculture, and Engineering Service (NRAES) publication edited by Charles L. Mohler and Sue Ellen Johnson, 2009, available for free download or purchase.
