Remember the “150 Rule” Associated with Turf Growth (4-23-12)

We have experienced spring weather conditions much earlier than normal. Our warm-season turfgrasses have made their spring transition from winter dormancy brown to summer green in color. However, they may not be actively growing as you would expect just yet.

We may be eager and impatient to see our lawns, sports fields, and golf courses 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 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 end of March and into April we have had some very nice warm and sunny days with day temperatures reaching into the high 70’s and low 80’s. However, 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, we must just remain patient and look forward to those warmer temperatures which will soon provide our turf conditions much more favorable for active growth.

Published April 23, 2012

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