Soil temperatures have been warming and reached the mid-40s °F last week at Rutgers Hort Farm No. 2 in North Brunswick NJ and are creeping into the upper-40s °F early this week. Dr. Clarke recommends that treatment of turf with a history of take-all patch be initiated when soil temperature averages 40 to 60 °F. Treatment of fairy ring should be initiated when average temperature is in the range of 50 to 55 °F. Waiting to treat beyond these soil temperature thresholds will increase the risk that control strategies are not as effective.
Table 1. Soil Temperature Data under Bentgrass Turf Mowed at 0.375-inch in North Brunswick, NJ on 17 March 2020 at 2:00 PM.
|3-inch Depth||Thatch-Soil Interface|
|Current||48 °F||50 °F|
|24-hour Average||45 °F||44 °F|
|5-day Average||47 °F||47 °F|
Additionally, the Forsythia bloom started last week in central New Jersey, which Dr. Matthew Elmore recommends as a traditional phenological indicator for preemergence herbicide programs on turf.