University of Maryland Extension

Lawn Diseases

Prevention is the best strategy for managing lawn diseases in home lawns. Proper fertilization and mowing, irrigating in early morning hours only and only when necessary, choosing the right type of grass, improving poor drainage and increasing air circulation around grassy areas will fend off serious problems. However, disease pathogens are present in your average lawn and when lawns are stressed and weather conditions are right a disease can occur.

When faced with a disease examine your lawn care practices. The major contributing factor for disease problems is overfertilization in the spring. Changes in the weather pattern and when cooler temperatures and rainfall return often lawns will recover from a disease. For example, brown patch can disfigure a lawn but the disease does not kill the crown of the grass and recovery is possible provided we are not in the middle of a drought. If by the fall the grass has not greened up the dead areas should be reseeded.

Fungicide applications by homeowners tend not to be very effective. By the time disease symptoms are noticed it is too late to apply a fungicide. Fungicides are applied preventively and will not cure what is already diseased. While fungicides are available to turf care professionals for disease suppression and control most homeowners don't have the proper application equipment and several of the most effective products, which are costly, are not for sale to homeowners.

If you can't find the answer to your lawn problem here, Ask Maryland's Garden Experts. A digital photo can be attached to your question. Also, get advice on pruning, vegetables, insects and much more. 

black slime on grass blades
distinct brown patches on lawn
Brown patch
hour-glass shaped lesions on grass blades
Dollar spot
mushrooms and rings of dark green grass

mushrooms in lawnMushrooms

white powdery coating on grass blades
Powdery mildew
pinkish lawn patches
Red thread
orange lesions on grass blades
dark ashy substance on grass blades
Slime mold

brown lesions on turfSummer patch

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