Can We Control Weeds in St. Augustine?

Jeffrey Derr and Adam Nichols

As our research station is located in southeastern Virginia, we receive questions about weed control in certain warm-season turf species that are not grown in western parts of the state. One common lawn species in our area is St. Augustine. It tolerates the heat and drought of summer and has better shade tolerance than bermudagrass or zoysia. We have evaluated cold tolerance in St. Augustine cultivars through an NTEP project. Although we have seen significant winter damage in certain St. Augustine cultivars, some, such as the Raleigh types, generally tolerate the winter temperatures we see in Hampton Roads.
Weed control, however, is a challenge in this turf species. In this article we will discuss current suggestions for controlling grass, sedge, and broadleaf weeds in St. Augustine, as well as some of the research we are currently conducting. Although you may not be maintaining St. Augustine, some of the treatments we are evaluating are proving useful in other turf species and thus may benefit your program.