Orchardgrass is a concern in our lawns because it is often mixed in with cheap grass seed, and since it’s a cool-season perennial like fescue, it is very difficult to control once introduced. Orchardgrass is a bunch grass that does not spread. It is paler in color than tall fescues, and faster-growing so just a few bunches will give lawns an uneven appearance. When buying seed, orchard grass will be listed under “other crop” instead of “weed seed.”
The best way to control orchard grass is to only buy grass seed that lists “other crop” as 0.0%. Once it is established, clumps are hard to kill and must be dug with a shovel and replaced with sod for physical control. For chemical control, this grass can only be killed with a glysophate product such as Hi-Yield’s “Killsall” or Bonide’s “KleenUp.” These products will also kill other lawn grass so they are only practical if the lawn will be overseeded in the fall or sod can be applied to the dead spots. A heavily infested lawn will have to be completely renovated in the fall.