Cool-season lawns may need second fertilizer application
Tall fescue and Kentucky bluegrass lawn owners know September is fertilizer time.
What they may not realize, however, is that September's meal typically gets used up by Thanksgiving. It's gone into helping the cool-season turfs not only green up again, but also recover from summer stress.
So, the plants have limited help when the time comes to get ready for winter.
"That's why some people call a second application in November the turfs' winterizer fertilizer," said Rodney St. John, turfgrass specialist for K-State Research and Extension.
The turfs' top growth slows down as the weather cools. But, so long as the plants are showing some green, they're still making carbohydrates--food. And, an application of nitrogen will boost their photosynthesis rate, St. John said.
A second feeding also helps tall fescue and Kentucky bluegrass stay green longer. In turn, the plants become stronger by improving their root growth, shoot density and winter hardiness, he said. Any food reserves that remain will help the lawn green up earlier the following spring and sustain growth into May.
St. John recommends applying 1 to 1.5 pounds of soluble (quick-release) nitrogen per 1,000 square feet of lawn. If lawn owners choose a turfgrass "winterizer" formula, it will have nitrogen as its major ingredient. But, owners will have to do some math to figure out how much to apply based on the size of their yard.