Slow spring turf growth and association with the “150 Rule” (5-3-10)

Most warm-season grasses have been slow this spring to transition from winter dormancy to active growth. While we may be somewhat eager and impatient to see our lawns, sports fields, golf courses, etc. turn from their winter brown to a healthy, solid green, it just will not happen until we have temperatures that are much more conducive to warm-season turf species growth. 

A rule-of-thumb guideline that many of us use to predict when our turf will really get active is the 150 rule.  This rule is derived by taken the night time lowest temperature and adding it to the daytime high. The sum of which should be near or above 150. As we look back to the month of April we had some very nice warm sunny days with day temperatures reaching into the high 70’s and low 80’s. However, the night time lows most often were in the 40’s or lower 50’s making the sums of the highs and lows far from the optimum 150 or higher. Therefore, we must just remain patient and look forward to warmer temperatures which will soon provide our turf conditions much more favorable for active growth.        

Published May 3, 2010

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu