Grow It Eat It: Maryland's Food Gardening Network

Late Blight of Tomato

Vegetable gardeners in Maryland should be on the lookout for late blight- a serious fungal disease of potato and tomato. The University of Maryland’s Plant Diagnostic Lab received a suspect tomato sample from a Howard Co. garden on June 12 and quickly determined that it was infected by late blight, Phytophthora infestans.

Late Blight Tomato

Despite the name, late blight can occur anytime plants are actively growing and is especially damaging during cool, wet weather. It first appears as dark, water-soaked spots on leaves. Leaves quickly shrivel and die. Dark brown spots also appear on plant stems. Our fact sheet HG# 38 Late Blight of Potato and Tomato contains more detailed information and photos.

fruit & foliage symptoms

Additional information is also available on our Plant Diagnostic site. Please call our toll-free number – 1-800-342-2507- and speak with a horticulture consultant if you suspect late blight in your garden. You can also send us a question and pictures through our web site.

For more information, contact Jon Traunfeld

Last updated: 07/23/2009

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