High heat, H20 and hungry hussies
High summer heat can easily push a garden past its prime as temperatures encourage plants to set seed and go dormant as a survival strategy. Keeping gardens going under those conditions requires copious amounts of water - something we are short of and has gotten expensive.
Looking to drought tolerant native and exotic plants will give you a break from high maintenance and dramatic water bills. When using exotics, be sure to inquire about their invasiveness. Not all exotics are bad guys.