I have a small plot of land, about 6 feet by 30 feet, where I grow vegetables. Although everything tastes great, the yield is extremely low. I get about six to eight tomatoes per plant, only two or three cucumbers per plant, and so on.
I am wondering: Could this be because I plant the same crops each year? Is it necessary for small-scale backyard gardeners to rotate crops? The only other reason I can think of is the lack of sun. We live in a canyon and get about four to five hours each day.
For an answer, we turned to Yvonne Savio, manager of the UC Cooperative Extension's Common Ground Garden Program for Los Angeles County. She oversees the training of master gardeners. Savio writes:
The short answer to your query is: Yes.
Crop rotation is important for every garden space, even if only 6 feet by 6 feet. Each family of plants uses up specific nutrients, and after several years of growing the same plants in the same soil, those specific nutrients are no longer available.
Amending the soil each season with manure and compost will revitalize it, but it's important to get those specific nutrients replaced. Rotating crops helps the soil in each micro-location become less depleted. A four-year rotation cycle will help.
Crops grown for their foliage can produce a good amount of food with less than six hours of direct sun daily — although more direct sun is always better. Plants that provide flowers and fruits must have more than eight hours of direct sun every day during their growing period because they have all that extra work to do.
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