Brown Yard Alert!
May 8, 2014
Many homeowners in the Greater Memphis Area are experiencing lawns that are not greening up this spring. I have spoken to several other lawn care companies in the area and they are seeing the same phenomenon. The lawns have the appearance of being dead in areas as small as 10 feet by 10 feet up to areas as large as an acre. Some lawns appear dead on one side and not on the other, some appear dead in the back and not in the front or vice versa, or some have a mottled appearance. There is no discernible pattern with the possible exception that some dead areas seem to follow property/mowing lines. Some of these areas also are contained within sidewalks and driveways.
We have dealt with this issue throughout the 30 years that we have been in business. However, we encountered epic proportions in 2011 and continued to wrestle with it in 2012, 2013 and now into 2014 with the severity of the problem being greater in some years than in others.
We are unsure as to the cause of the problem, but our knowledge and experience leads us to the following opinion (subject to change as we receive more information).
This appears to be a disease that seems to have attacked the lawns in the fall, close to the time they go into dormancy. In this aspect it is similar to Spring Dead Spot, in which the grass actually dies rather than merely going dormant. The damaged turf is not apparent until spring when the damaged areas fail to green up. Spring Dead Spot is usually limited to small spots from 6 inches to 3 feet in diameter.
We have since discovered an insect new to this area called a “hunting billbug” or Sphenophorus venatus vestitus Chittenden. It is a weevil that also is commonly known as the “zoysia billbug” in Florida, where it has been reported as a pest to various grasses, especially in nurseries. During local lawn inspections of brown grass, we have found these bugs to be active. The problem can spread from one lawn to the next.
Fertility, drainage, and mowing practices do not seem to have made any contribution to the severity of the disease.
Course of action
At this time we think that the only effective course of action is to scalp and dethatch the lawns in order to allow the sun to warm the soil. The lawns should slowly green up, but it could be late summer before the lawns look normal. If some of the lawn is partially shaded the lawn may not recover in those areas.
We have not seen this reoccur in the same lawns the following year. There may be some sort of inoculation against the disease, or it may just be luck.
About 95% of the lawns affected in 2011 made a full recovery by mid-summer, 4% more by late summer, and 1% not recovering fully in 2011.