Mow your HGT at the desired height; anywhere from 2.5 to 3.5 inches tall.
Apply pre-emergent herbicide. This will cut down on summer weeds.
Don’t over water. HGT needs about one inch of water per week, taking into consideration rainfall.
Apply fungicide (if needed). If you have had a fungus or disease in your HGT in the past or have quite a bit of shade in the yard, you should apply a systemic fungicide to prevent future outbreaks.
Summer
When mowing never remove more than 1/3 of the leaf blade. If you remove more than that, you will stress the grass and it may go brown for a short time. If returning from vacation, you may have to mow multiple times to get the grass back to the desired height. Wait about three to five days between each mowing.
Do not over water the grass. HGT only needs about 1” of water weekly. Water for longer periods of time, less frequently, and in the early morning hours. Take rainfall into consideration.
Treat with a broad-spectrum insecticide (if needed). If you use a granular variety, water the lawn immediately after application to help get it into the soil.
Fall
Apply fungicide. This will help the grass enter colder months in a healthier condition.
If you have had fungus before, you may need multiple applications in affected areas.
During the fall mowing will occur less often – keeping your bluegrass lightly higher will encourage deeper root growth for the winter.
Water less as temperatures drop – too much water will lead to disease.
If you haven’t had past problems with winter weeds, you can forgo herbicide in the fall. If you do get winter weeds, apply a pre-emergent herbicide for prevention.