Mow your bluegrass 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 overwater. Bluegrass needs about one inch of water per week including rainfall.
Apply fungicide if needed. If you have had a fungus or disease in your bluegrass in the past or have quite a bit of shade in the yard, you should apply a systemic fungicide to prevent future outbreaks.
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 you are 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 overwater the grass. Bluegrass only needs about one inch 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 soil absorption.