Many people like to grow a few tomato plants even if they typically do not grow a large garden. A few plants are nice to be able to supply some fresh tomatoes for a salad or BLT sandwich.

Unfortunately, reports have been coming in that Late Blight has been found on tomatoes from home gardens in several states including Pennsylvania and New York. Infected plants were found at some large retailers, it is possible that infected plants may be now widely distributed across the country.

Weather conditions a few weeks ago in the area, where temperatures were cool to warm with high moisture levels from rain or heavy dew, have been very favorable for late blight to develop.

According to OSU Extension coordinator Chris Bruynis, gardeners should destroy plants already infected – pull out the entire plant, immediately bag it in a plastic bag, and dispose of the closed bag in the garbage.

Do not put the plants on a compost pile or in a composter, or leave them lying about. Live plant tissues serve as a source of inoculum, and uprooted plants may support active spores of the pathogen for some time. Healthy-looking plants should be protected with a fungicide containing chlorothalanil or copper; several brands are available in garden centers and other retail outlets. Chlorothalanil is more effective than copper in controlling late blight.

If you are not sure that the disease symptoms you see on tomatoes or potatoes are caused by late blight, you may bring a sample to the Ohio State University Extension office and we will submit them to the Plant and Pest Diagnostic Lab. There is a fee to have the specimens packaged, shipped, and diagnosed that varies based on what disease is to be identified.

More information on late blight is avaialable at http://ohioline.osu.edu/hyg-fact/3000/3102.html