Late Blight Tomatos

Asked March 11, 2014, 7:49 PM EDT

The past several years we have been decimated by late blight. We understand this is a fungal problem, but don't quite know how to deal with it. Our first two years were in the garden were very productive and clean, but the past three years have been nothing but late season blight. This past year we increased the spacing for more air circulation to keep the plants drier, to no avail. We would prefer an organic method of control, but have read conflicting information. I decided to turn to the area experts . . . you. Any information will be sincerely appreciated. Our garden is located in Burrell Township, just outside of Blairsville.

Indiana County Pennsylvania

1 Response


We first should identify which blight/s affected your tomatoes. There are three blights which could have caused damage on your plants either alone or in combination. The blights are early blight, septoria leaf blight, and late blight. We had a number of folks with tomatoes affected by septoria last year. Early blight is a fungus that over winters here and typically starts on the lowest leaves of the plant and slowly works its way up the plant. Septoria is also caused by a fungus. Late blight is caused by a water mold and does not overwinter here unless it has living tissue of a tomato or potato plant to survive on. The fact sheet goes into more detail on the life cycle. The following link takes you to our late blight fact sheet: The following link takes you to a fact sheet on septoria and early blight: Also, tomato disease management strategies:

Please read the factsheets and if you need clarification or additional information, please let me know.