Much of the nutsedge that has begun to emerge is yellow nutsedge. It often comes to a location from sod or imported soil. It has historically been a challenge in wet areas, as the plant produces nutlets that lie dormant in the soil and then germinate following a rain event. The growth and success of yellow nutsedge is due to its ability to colonize an area, tolerate mowing, and reproduce via seed and underground nutlets. Successful control programs include avoiding the use of contaminated soil and a well timed application of Halosulfuron (Sedgehammer) applied with the appropriate crop oil for necessary absorption. The best timing for control of above AND below ground plant parts is in the next few weeks around the summer solstice when plants begin to translocate sugars for storage in the nutlets. This will burn back the existing foliage and translocate the herbicide to the nutlets for both post and preemergence control. Be sure the nutsedge is not under moisture stress when making the application. Be sure to read and follow all label directions, including those associated with use of crop oil concentrate. Warm weather increases the potential for injury to desirable cool season turf that might also be under moisture stress.-from Dr. Frank Rossi’s blog, shortCUTTS