It appears to be your first time visiting GDDTracker
Please enter your zip code for a customized experience. Also, be sure and watch our video introduction video.


MSU Poa Seedhead Flush (GDD 22)
through Wed, Mar. 4. 2015


To view color key / range descriptions, please enter your zip code at the top of the screen.

Generously Supported By:

Latest Updates

March 2nd, 2014Ready, Set... Reset, Go!

The GDD totals were mistakenly reset on Jan 3rd instead of Feb 15th. This has been corrected. Some alerts may be resent due to the change. Thank you!

April 9th, 2013GDDTracker Expands Coverage

With initial funding provided by the Michigan State University and the Michigan Turfgrass Foundation, GDDTracker has been helping turf managers schedule Poa annua seedhead suppression applications throughout the Great Lakes states since 2004. Over the last couple years we've been considering several strategies for expanding the geographical reach of GDDTracker beyond our base region. After much consideration we have decided to expand coverage from Colorado to the atlantic coast. Historically the models we've used to schedule PGR applications to suppress Poa seedheads in our region have been successful but as we move outside of our immediate comfort zone users should keep in mind that the ultimate combination of personal observations, experience, and GDD models should all be considered when scheduling applications. Although GDDTracker started as a guide for scheduling PGR applications for Poa seedhead suppression, over the years we have added models for crabgrass preemergence, spring broadleaf, and others. As GDDTracker grows we will continue to move forward with additional models. We hope you find GDDTracker useful for your operation and as always your feedback is always encouraged.