How to Fertilize Your Garden or Lawn in Late Fall
The exact timing on when to fertilize varies based on weather conditions and your climate zone; however, the final fertilizer application should be done sometime in November in most regions. This is the point when the grass has stopped growing or has slowed down to the point of not needing to be mowed.
If fertilizer is applied too early while grass or garden plants are vigorously growing, it can invite winter injury and snow mold the following spring. However, do not wait until the ground freezes, and don’t apply fertilizer over snow or ice.