Don’t Apply Pre-Emergents Too Early

Yes, there is such a thing as applying pre-emergents too early. But how soon is too soon?

You’re probably eager to control crabgrass and goosegrass on your golf course, preferably before they become a visible problem. But pre-emergent herbicides are most effective when applied at the proper time, and sometimes that requires patience. 

Pre-emergent application timing is less about the calendar than it is about soil temperature. Most crabgrass and goosegrass germination happens when the top two inches of soil are between 60°F and 70°F. Apply pre-emergents at soil temperatures between 50°F and 55°F for optimal results. 

If you apply pre-emergents too far in advance of the proper temperature, they will be less effective at the time of weed germination. Application timing is crucial because the chemicals naturally degrade over time. Likewise, split applications are a good way to maintain herbicide activity throughout the growing season. Hot summer temperatures also contribute to degradation of the pre-emergent chemistry, which is another good reason to do split applications.

Michigan State’s Growing Degree Day Tracker is a good tool for determining the best time to apply pre-emergents on your golf course. Your ATS sales representative is also happy to advise on timing and products. Contact them today with any questions you may have.