When To Fertilize Lawn In Flagstaff

Be careful!  Applying a high-nitrogen fertilizer in April may cause grass to grow too fast, before roots can grow to support the lawn. This makes a lawn less tolerant of the brutal June heat.

In most cases, an application of fertilizer in April is not needed when lawns were fertilized the previous fall or when clippings are mulched back into the yard.  If an April application appears to be necessary, apply the fertilizer at a reduced rate.

The Schedule

• First fertilizing between May 1 to June 15
• Second fertilizing August 15 to September 15
• Third and final fertilizing October 1 to November 1

The cool-season grasses benefit the most from fall applications of fertilizer, usually sometime in October or November, as shown in the bullet points above.