Start fertilizing cool-season grasses about six weeks before the average first frost in your area. Fresh out of summer dormancy, these grasses benefit from added fall nutrition, which spurs new shoot, stem and root growth, and helps increase their food reserves. 1 September and October are prime cool-season fertilizing times for much of the United States.
1. Michael Goatley Jr., Shawn Askew and David McCall, “Fall Lawn Care,” Virginia Cooperative Extension.
Feeding Cool-Season Lawn Grasses
Early fall is a perfect time to tackle tough turf weeds. Existing perennial weeds are still active and hard at work storing up food reserves, which leaves them very vulnerable to treatment. Weed killers get swept through the plant along with carbohydrates meant for energy stores in stems and roots, and few parts of the plant escape. 3 As warm-season weeds go dormant, movement through weeds slows or stops and resilience increases, making treatment more difficult.
Never use any weed product on a lawn grass unless the grass is noted on the product’s label.
Spray when weeds are small and actively growing when temperatures are below 90 degrees Fahrenheit, 85 degrees Fahrenheit for Bermudagrass.
For perennial weeds such as Plantain, Dandelion, Knotweed and Clover, apply a post-emergent herbicide in fall to send the killing chemicals directly to roots. This treatment will help reduce the numbers of these weeds in spring.
Do not use on Bahiagrass, Carpetgrass, Centipedegrass, St. Augustine including Floratam or Dichondra.
Application on Bermudagrass may cause temporary yellowing or discoloration but full recovery can be expected.