Lawn Care During the Heat


Most of us have Kentucky Bluegrass lawns, which require about two inches of water per week during the summer months.  Although, there are many factors affecting the amount of water required.  A shady lawn may not require as much, but don’t forget that if the shade comes from mature trees, then they will require some water too.  Open and windy exposures will cause the lawn to dry out faster than those in shady locations.

Try not to water during the heat of the day, set your controller to run between 10pm and 8am if possible.  It is typically less windy and more humid during this time, which will result in less evaporation.  Watering at night along the Rocky Mountain Front Range will not encourage disease development as many believe.

Water only as much as your soil will accept!  The goal should be to moisten as much of the root zone as possible.  Be careful if you have clay soils not to over water.  You may need to break up the watering into a couple cycles so you are not getting a lot of runoff and wasting water.   Likewise, if you have sandy soils, watering too deeply allows water to percolate past the root zone, wasting precious water.  Many of the latest irrigation controllers have the technology and flexibility to overcome these issues.  Pay close attention to steep slopes as well.  These areas may need some additional irrigation as water tends to run off more quickly.


Cool season grasses, such as Kentucky Bluegrass, Ryegrass and Tall Fescue should be mowed to a height of 2.5 – 3”.  One of the biggest mistakes is mowing turf too short.  This can result in higher incidence of weeds as well as disease and insect problems.  Mowing too short can also result in decreased drought and heat tolerance.

Mowing frequency can vary throughout the season.  You may have been mowing more often this past spring when it was a bit cooler and was actively growing, than you will need to during the heat of the summer as it becomes much hotter and drier.  Mow as often as is required to ensure you never remove more than 1/3 of the overall grass height in one single mowing.


Nitrogen is the most important nutrient for providing a nice looking lawn.  Be careful not to over fertilize in the heat of the summer as it can cause excess growth resulting in more mowing and watering.  Don’t forget to fertilize in late-fall, this is the most important fertilization of the year!