Question: I have a small fescue lawn that is being taken over by what appears to be Bermudagrass or some type of large-blade thick, dense grass that is much greener and thicker than the fescue grass. What can I use in our climate to kill the invading grass without killing my fescue?
Bermudagrass that invades lawns is not typically dark green and is not dense in a bunch. It produces stolons, so you can usually identify it because it wants to creep along the surface of the lawn.
If it is dark green and in clumps, it might be a fescue or rye. Because Bermudagrass will not grow in shade, if we keep the lawn mown high, do not use line trimmers to edge the lawn, do not mow or line trim the grass next to sprinkler heads and keep it dense and healthy, it usually keeps Bermudagrass out due to shading of the soil.
Once you have Bermudagrass, it is tough to get rid of. You should get it when it first invades, if possible. This would be with spot sprays such as Roundup in these locations and reseed.
You do this in the fall. After one week, you cut or remove the sprayed grass from those locations and reseed it or cut small pieces of sod and resod those areas. Keep it wet the first two weeks as it starts to root into the soil. You gradually back off on the frequency of irrigation and increase the amount on those spots. This forces it to root more deeply. Finally, after about eight weeks, you revert to your sprinkler system.
Bob Morris is a professor emeritus in horticulture with the University of Nevada and can be reached at email@example.com. Visit his blog at xtremehorticulture.blogspot.com. For more advice, see the Home section of the Las Vegas Review-Journal.