(Kristin Eberts) [Order this photo]
I have tried to dispel this misconception by often suggesting that the best time of the year to seed a cool-season lawn is in the fall. But suppose you don't need to seed. Then when do you want to get started improving your cool-season lawn? The answer of course, is in the fall.
Cool-season grasses are placed in that category because they grow most rapidly in cool seasons. You want to make sure that they have plenty of nutrients available during the period of rapid growth. Therefore you want to fertilize your cool-season lawn in the fall.
Apply a high nitrogen fertilizer such as a 28-0-4 to your lawn early in the fall, preferably in September or early October. The nitrogen will enhance rapid leaf growth, needed to support good root growth.
You will notice not much phosphorous (P) and potassium (K) are in the fertilizer I suggested. Most of the soils in the Heartland have adequate amounts of P and K. If you find that after fertilization your grass leaves have a purple cast to them, your soils could be lacking P or K. You should then make an application of a fertilizer such as a 9-13-7 with micronutrients. This should eliminate that nutrient deficiency that is indicated by the purple cast.
About six to eight weeks after making the first fall application of high nitrogen fertilizer you should come back and make another winter application of fertilizer. This so called winterizer application of a 25-0-6 will encourage cool season grasses to continue growing throughout the late fall and winter.
Because air temperatures are cool in the late fall and winter, fertilization in the late fall will encourage cool-season grasses to spend their energy growing roots and not tops. A good root system is essential for a good turf to be able to withstand the stresses of cold, excessive rainfall, drought and extremely hot temperatures.
It may be the middle of October, but get out there and get your lawn for 2012 off to a good start by fertilizing it now and at the end of November or even into December.
Send your gardening and landscape questions to Paul Schnare at P.O. Box 699, Cape Girardeau, MO 63702-0699 or by email to firstname.lastname@example.org.