Fall Lawn Fertilization
September, October and November are the best months for fall lawn fertilization. When you fertilize during this time period depends upon the condition of your lawn. If you have not watered your lawn this summer, fertilize as soon as the rains start. If your lawn is green and growing well, wait a month or so. Fertilizing in October or early November will keep your lawn beautiful through the winter without increasing the growth rate.
One of the great benefits of fall fertilization is that it not only gives immediate results, but it also carries over into spring. Fall is the time when grass makes a lot of new growth under the ground. New roots and crowns cause turf to thicken. Food produced by the leaves is stored for the winter and next spring.
Most brands of lawn fertilizer have developed formulas for fall fertilization. They generally contain more potassium which makes grass more resistant to winter weather. However, I have found that almost any lawn fertilizer works well in the fall. Research has shown that nitrogen is taken up by grass roots and used to make amino acids which are stored in grass crowns and roots. These amino acids are available for immediate use in early spring when soil is too cold for roots to take up nitrogen. The result is a more attractive spring lawn.
Read the “guaranteed analysis” label to make sure lawn fertilizer contains iron. Iron causes grass to turn dark green, sometimes almost over night.
Fall is also an excellent time to apply lime to lawns. I like to lime my lawn every 2 to 3 years to reduce soil acidity.
Wait until late November to fertilize trees and shrubs. By then, top growth has become dormant, but roots can continue to take up fertilizer. Stimulating new growth now will make some of our more sensitive broad leaf evergreens more susceptible to winter damage.