Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons. Our farm is using a four year crop rotation on a five field system to minimize pest build-up. Four of the five fields are about an acre with one larger field that is about two acres. Each of the smaller fields are planted with a single crop while the larger field is divided into four strips. In any give year, we will have about an acre-and-half in each crop. This lets us plant an acre-and-half planted each year with only cover crops. We created a graphic to illustrate.
Nightshades -> Allium -> Legumes -> Cucurbits -> Brassica
As proactive garlic growers, we take measures to prevent potential pest problems. One such pest, that we recently learned about thanks to Honeyhill Farm in Livonia, New York, is the wheat curl mite. Wheat curl mites are microscopic white, wormlike organisms about 0.01 inch (0.25 mm) long. These mites feed on lily-family bulbs (including garlic and onions), cereal grains (oats, winter rye, barley) and wild grasses. Fields rotated into garlic from cereal grains may have higher levels of wheat curl mites. The experts say that nearly, all small grains are susceptible to wheat curl mite, and could potentially serve as a “green bridge” for the mite to infest allium crops. Instead of oats and winter rye, we will use crimson clover, hairy-vetch, yellow mustard, and tillage radish as cover crops. In general, the recommendation is to avoid planting successive small grains, grass, onion or garlic crops. Doing this disrupts the pest travel on the green bridge and protects the garlic with a “green drawbridge”.