In many situations, you don’t want to completely kill a spot of bermudagrass in a lawn – – you just want to gradually control the bermudagrass in your main turfgrass.
There are three solutions:
BioAdvanced Bermudagrass Control (click for sources) is labeled for use in fescue lawns. DO NOT use on St. Augustine [including Floratam], bermudagrass, zoysia, centipede or bahia lawns.
Q: I have heard you discuss on your radio show removing bermudagrass from fescue lawns. In my landscaping business we use Fusilade to effectively do this.
A: Fusilade (click for sources) is labeled for bermudagrass control. My observation is that it is rarely found on nursery shelves but is typically used by professionals like yourself. I think this is good because failure to dilute and apply this chemical precisely will result in harm to fescuegrass and zoysia as well as bermudagrass.
The best time to apply fluazifop to fescue for suppression of bermudagrass is in spring just as the bermudagrass is sprouting green stems.
Q: Would triclopyr burn back bermudagrass in fescue lawns?
A: Yes, it would. The label on Weed B Gon for Chickweed, Clover and Oxalis (click for sources) states that it should not be used on bermudagrass lawns. Bermudagrass is more sensitive to triclopyr than is fescue.
As with fluazifop above, using triclopyr in this way is an “off label” use. You assume all responsibility for the outcome.
The best time to apply triclopyr to fescue for suppression of bermudagrass is in spring just as the bermudagrass is sprouting green stems