MANHATTAN, Kan. -- November is second only to September as the most important month to feed tall fescue and Kentucky bluegrass lawns.

That may not seem logical, even for cool-season turfs. Their top growth almost stops in late fall.

“But, the plants are still making food – carbohydrates – through photosynthesis. And, they’re storing up everything they don’t need for growth right now. Nitrogen in November helps boost those photosynthesis and storage rates,” said Ward Upham, horticulturist, Kansas State University Research and Extension.

In turn, Upham said, the benefits for cool-season turf plants can extend for many months, including:

*  Improved root growth and shoot (density) development until the lawn enters winter dormancy.

*  Improved winter hardiness.

*  Carbohydrate reserves that help turf green up as early in spring as the weather allows.

*  Reserves that sustain growth into May without a nitrogen application in March or April.

“Nitrogen applied in early spring is riskier because it can lead to excessive shoot growth and reduced root growth -- just as cool-season turfs should be toughening up for summer,” he said.

K-State recommends applications of 1 to 1 ½ pounds of actual nitrogen per 1,000 square feet of lawn in November. Upham noted that this is not the same as pounds of fertilizer, because only a certain percentage of most fertilizers is nitrogen. For example, achieving 1 pound of nitrogen requires four pounds of a 25-4-4 fertilizer.

“Because the growing season is nearly over, you need to use a water-soluble or quickly available nitrogen carrier, such as urea or ammonium sulfate. Or, you should look for turfgrass fertilizers that contain soluble nitrogen,” he advised.

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