Spots on grass; yellowing - Ask Extension
I notice some yellow patches in my lawn and spots on some grass blades. The lawn is on the west side of the house and portions are shaded by tall a bl...
Knowledgebase
Spots on grass; yellowing #798731
Asked June 30, 2022, 8:08 AM EDT
I notice some yellow patches in my lawn and spots on some grass blades. The lawn is on the west side of the house and portions are shaded by tall a black gum and an oak tree; branches are at least 6 ft from the ground. I have only watered once or twice, and I think its a tall fescue but not sure. I sent a message about a week ago, but I've had problems with that email since I've had to use my PC instead of my Mac. The current email works fine...sorry. I've attached some new pictures in case the last email did not go through.
Henrico County Virginia
Expert Response
I forwarded your pictures from the last submission and this one to two of our turfgrass specialists. Here are their thoughts.
I suspect that there is some active brown patch based on environmental conditions and the presence of the lesions but there is likely more going on. Drought could be part but underlying poor soil may be the driving factor. Also the thinning that has occurred for some other reason be it soil-related, environmental extremes (temp/moisture) or a previous disease (something like gray leaf spot or Pythium blight?) that might have caused such complete thinning and the matted foliage.
Fungicides are preventative, not curative. So, you could apply a fungicide to keep the brown patch from spreading. Typically we do not see brown patch kill the plants completely but in combination with drought or heat plants can die.
Lawns typically require 1" of rain/water per week during the growing season. this can be either from rain or irrigation. If you have only watered once or twice, there is likely drought stress in the lawn as the new grass has not had long to develop a deep root system.
I suspect that there is some active brown patch based on environmental conditions and the presence of the lesions but there is likely more going on. Drought could be part but underlying poor soil may be the driving factor. Also the thinning that has occurred for some other reason be it soil-related, environmental extremes (temp/moisture) or a previous disease (something like gray leaf spot or Pythium blight?) that might have caused such complete thinning and the matted foliage.
Fungicides are preventative, not curative. So, you could apply a fungicide to keep the brown patch from spreading. Typically we do not see brown patch kill the plants completely but in combination with drought or heat plants can die.
Lawns typically require 1" of rain/water per week during the growing season. this can be either from rain or irrigation. If you have only watered once or twice, there is likely drought stress in the lawn as the new grass has not had long to develop a deep root system.
