Hello Randy,

It is still too early to put down fertilizer with pre-emergent herbicide in Leelanau County. Pre-emergent herbicide should be applied when soil temperature is between 50 and 55 degrees F. The best natural indication that the soil is at the correct temperature is the bloom of the forsythia shrub.

MSU also maintains a Degree Day tracker that monitors daily temperatures at various locations and estimates the overall cumulative “warming” for the season. This Degree Days measure can be used to predict certain natural phenomena. One that is tracked is the temperature for pre-emergent herbicide application. The GDD Tracker can be found at https://gddtracker.msu.edu/

Enter your zip code and choose “Crabgrass PRE” in the right panel. The yellow band shows where it is too early to apply pre-emergent herbicide and the green band shows where it is optimal to apply. As you can see, Leelanau County is just in the yellow band on the degree day tracker.  When your zip code is in the green, it is optimal time to put down pre-emergent herbicide.

Another excellent reference can be found at https://www.canr.msu.edu/news/timing_crabgrass_pre_emergence_applications

Remember whenever using any fertilizer or herbicide product, read and follow the label directions. And avoid applying where runoff can enter the watershed system.