September 18, 2012
Since I put up the post on August 2 about bermudagrass in Iowa, I have had several other calls about bermudagrass invading lawns and sports fields. These calls have come from Burlington, Council Bluffs, Des Moines, Keokuk, Davenport, and Red Oak. I have also been getting samples to identify. I have had more contacts on bermudagrass in the last 8 weeks than in the previous 33 years combined. The mild winters and hot summers are resulting in this species becoming a significant problem in some regions.
The usual questions is, “How can I kill it?”. There is no selective control in cool-season turf. You have to kill it with Roundup. It is very hard to kill. It will likely take several repeat applications of Roundup, and even then, its extensive rhizome system results in regrowth. Complete soil sterilization with methyl bromide may be the only sure way to remove it from critical areas like sports fields and sod fields. Of course a couple of cold winters would also take it out. That is the reason it was not here before.
Here are some pictures that I received from Eric Van Ginkel of the Iowa Cubs concerning the Dowling High School softball field. The sodded this field just 5 years ago with Kentucky bluegrass and bermudagrass has spread extensively in the last couple of years.
If anyone else has a major infestation, send me some pictures and I'll get them up on the blog.
Figure 1. The Dowling softball field. This are the biggest patches of bermudagrass that I am aware of in Iowa.
Figures 2 and 3. Eric wrote that these patches were discolored by an herbicide. He did not say which herbicide, but it looks like tenacity.
Figure 4. The extensive stolons of bermudagrass. This is what makes it spread so fast.