Fertilize the lawn. Fertilize all flowering plants about to bloom. Fertilize roses, except most antique roses. Pinch off dead flowers. In particular pick off spent blooms from crepe myrtles to bring on extra flowers in the fall.
Hot weather is hard on newly transplanted plants.
If you do transplant, shade them for a few days with the temporary shelter of an umbrella or wooden shake. Stake tall sprawling flowers. Harvest vegetables as they ripen. Pick them early in the day. Continue to monitor your watering system.