You know it’s September when kids are back in school and holiday decorations are already in all the stores. It’s also a critical month for cool-season grasses. This is the perfect time to fertilize cool-season grasses such as Kentucky bluegrass and tall fescue. Sixty to seventy-five percent of all nitrogen applied to cool-season lawns should be laid between Labor Day and the year’s final mowing.
Fertilizing in September helps nourish cool-season grass in a couple different ways:
- It improves turf density. Fertilizing now encourages the growth of new tillers and/or rhizomes and stolons.
- It strengthens roots. The root system will be better able to survive the winter’s challenges as well as the stresses of next year’s growing season.
Choose slow-release fertilizer with 25 to 50 percent nitrogen. Use one pound of nitrogen for every thousand square feet of turf.
This is also the best time to repair any problems with cool-season grasses. That includes any bare spots that might have appeared, and aerating if necessary to enable the roots and soil to take up essential nutrients as the season winds down. The earlier the fixes, the better your grass will look next year, as some cool-season grasses such as tall fescue are susceptible to the winter’s harsh conditions if these repairs come too late.
September is also the perfect month for last-minute weed control. For weeds such as clover, dandelions, wild violets, black medic and plantain, applying broadleaf weed killer this month will help get the problem under control. Look for an herbicide with two or more active ingredients.
Be careful when using fertilizer and weed repellants around desired plants, as they may damage flowers, trees, shrubs or vegetables. Pick a calm, sunny September day when no rain is forecasted and the temperature is above 50 degrees!