Vigorous Turf Growth Dependent upon the “150 Rule” (05-06-13)

Even though our warm-season turfgrasses have made their spring transition from winter dormancy brown to summer green in color they may not be actively growing as we would expect just yet due to the cool, wet spring most of us have experienced. While we are eager and impatient to see our lawns, sports fields, golf courses, etc. get that dense healthy green canopy and recover from any thinned areas 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 can help us 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. We have experienced a few very nice warm sunny days with day temperatures reached into the high 70’s and low 80’s but the night time lows most often were much cooler making the sums of the highs and lows far from the optimum 150 or higher. Therefore, remain patient and look forward to those warmer temperatures which will soon provide conditions much more favorable for active turf growth. Since many lawns have been way too wet to mow maybe it is a blessing that the turf is not growing that fast right now.

Published May 6, 2013

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. [email protected]