Hi, Kyle

The one piece of information needed during this extreme heat and drought is your watering schedule. Have you watered? If so, how often and how long?

Lawns, herbaceous plants, shrubs, and trees are all taking a hit right now... if not from lack of rain, then from the heat that does not break overnight. Just based on these photos with no other information, I'd say they are drying out, like many other plants. 

If they still have small, black spots, then you can pass those along. Using any chemicals with the heat stress is only going to stress plants even more. 

For now, you can cut the browned leaves off, water in the morning and on the ground - not the leaves, and deep water (slowly) to let the soil absorb down into the roots. You won't need to do that every day. If the soil is dry down to about 2 inches, then it's time for more water. 

It appears that you have rocks as mulch. While this is helpful in some situations, rocks are likely not conserving water moisture in the soil like hardwood mulch would, so watering more often, may be necessary. However, it is quite possible to overwater in drought, so be cautious of that.

Best of luck!