Early vegetable planting and soil preparation
If a cold-frame isn’t available to start early greens, wait until soil temperatures have warmed to 40 degrees F at a depth of 4 inches at 8 a.m. Soil temperatures recorded on the CSU campus weather station over the last five years show that the last few days of March. Daytime air temperatures that are consistently 40 degrees or more are also desirable. The list of cold tolerant vegetables includes broccoli, cabbage, kohlrabi, onions, lettuce, peas, radish, spinach and turnips.
If a winter cover crop of rye or Austrian winter pea was planted in the fall, it should be tilled in mechanically or turned under with a spade a month before planting or seeding. Decomposing, turned under plant material (“green manure”) consumes soil oxygen and can create plant health problems if not tilled in ahead of time. This decomposition is necessary to realize the soil fertility and soil structure building benefits from the planting of cover crops.
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Updated Friday, April 19, 2013