The GDD Tracker website (sponsored by the MRTF and Purdue University) is predicting that crabgrass is now germinating at most Indiana Locations (see figure below). The GDD Tracker estimated that crabgrass germinated in Lafayette, IN after Wednesday this week and I was able to confirm this by identifying newly germinated crabgrass (see figure below) both in Lafayette and West Lafayette.
For those of you that have not yet applied a preemergence herbicide (crabgrass preventer), it is still possible to control crabgrass if you choose a product that contains dithiopyr – the only preemergence crabgrass herbicide that also has some early postemergence activity on crabgrass.
The weather is now changing. We will continue to monitor the growing conditions and provide updates as needed on turf growth and turf pests in 2012.