Apply Late-Season Nitrogen Application in November November is the time to
give cool-season lawns the last nitrogen application of the season. Why
November? Because while top growth slows in response to cool temperatures,
grass plants are still making food
(carbohydrates) by photosynthesis. A November nitrogen application helps
boost the photosynthesis rate. Carbohydrates that are not used in growth are
stored in the crown and other storage tissues in the plant. These
carbohydrate reserves help the turfgrass green up earlier in the spring and
sustain growth into May without the need for early-spring (March or
April) nitrogen. Those early-spring nitrogen applications are less desirable
because they can lead to excessive shoot growth and reduced root growth.
Other benefits of November-applied nitrogen for cool-season grasses include
improved winter hardiness, root growth and shoot density.
How much should you apply? One to 1 to 1 ½ pounds actual nitrogen per
1,000 sq. ft. of lawn area is sufficient. In order for this application to
be effective, the nitrogen must be readily available to the plant, because
the growing season is nearly over. Therefore, for a November application,
use a soluble (quickly-available) nitrogen carrier such as urea or ammonium
sulfate. Many turfgrass fertilizers sold in garden centers and other retail
outlets also contain soluble nitrogen. Avoid products that contain
water-insoluble nitrogen (slow-release) for this application. As always,
sweep up any fertilizer that gets on driveways, sidewalks, or streets and
reapply it to the lawn.