Depending on your grass type, fescue or Bermuda grass for example, your lawn my not be too happy under the current heat wave we’re experiencing. Especially fescue lawns. Bermuda takes the heat and humidity better. Another factor is humidity which leads to turf disease. Heat and humidity combined greatly increases the likelihood for issues. Currently Brown Patch is very prevalent here in the Tennessee valley. Some lawns are more susceptible than others. Factors like irrigation and improper fertilizing play a role too.
Lawn disease/fungus really can not be controlled, only managed. Treatments are usually not cheap. Some products I endorse are Headway and Heritage fungicide. Both from the same family of chemistry. Usually starting around mid late May here in the south east is best to prepare for an application. Then it’s best to switch to a different chemistry like Eagle fungicide. Best to water these applications in, as they work within the soil to help mitigate and manage the disease/fungus.
Mowing practices is another factor. Sharpen your mower blades. You want to cut the grass not tear it. Mowing height is another component. Not too short as to stress the turf, yet not too high as to where the grass is not able to dry out during the course of the day. Most mow too low. Yet some of us like the tall cut look. Which is ok early in the year, yet can lead to issues if it’s too damp for an extended period of time.
Fertilizing is another concern. That’s often times a balancing act. Ph is another item to look into as well. If a lawn is over fertilized, usually too much nitrogen, the turf becomes more susceptible to fungus and diseases. Getting a soil test is a good way to gain a baseline of the health of your soil. You can then adjust your fertilizing accordingly.
Although rain, heat, and humidity are elements that can’t be controlled. You then focus on what you do have management over. Usually come late July/August the issues subside.
Come Fall you can aerate and over-seed to rebuild your lawn if any damage has occurred. If you want a nice fescue lawn, you’ll need to give it attention. Either try to stay ahead of the game or rebuild the turf in the Fall. Depending on when you address the issue will also determine the issue of weeds. Some are easier to eradicate that others.