Plant Pathology Infobytes

March 12, 1997
How's the Health of Your Garden Compost?

County Extension Offices receive questions on a wide variety of home gardening topics. For example, a gardener called in recently with a question on composting. Since an increasing number of home vegetable producers are finding that compost can be a garden's best friend, the following information provided in response to the question may be useful to other gardeners.

Question: "When I cleared off my garden last fall, I added the debris to my compost pile. Since some of my garden plants were diseased (I had blight on my tomatoes), will it be okay to use this compost material in my garden this spring?"

Answer: If your garden debris was composted properly, the high temperatures reached during the composting process should have destroyed most of the plant disease organisms present, including the fungus which caused the blight problem in your last tomato crop. However, if your compost pile wasn't turned every two or three weeks so that material on the outer edge of the pile was moved toward the center (to the "hot zone"), where it could be broken down completely by compost microorganisms, you might want to reconsider using it in your vegetable garden.

It's important to remember to turn the compost in this fashion since incompletely composted organic material could still carry disease fungi and other problem microbes and add to garden disease problems. If you have doubts about the safety of the compost, you might want use it in another area (landscape beds, for example) to be on the safe side. Or, you might want to re-compost the material for use later in the gardening season.

Compost is a great way to turn organic material into a highly beneficial soil conditioner. Compost improves the structure, tilth, fertility, and water- and nutrient-holding capacity of garden soils. It's a great step toward improving your garden, but just make sure your compost is healthy.

For additional information on constructing a soil-compost pile, refer to Extension Publication 1091 "The Garden Tabloid," available free at the County Extension Office.


Written by the late Dr. Frank Killebrew

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