There is one thing that loves being blasted by the August heat, and that is bougainvillea. Mine have been blooming all summer. I followed a tip I got at Shoal Creek Nursery one day. 
They have amazing hanging baskets of bougainvilleas, spilling over with blooms. I asked how they achieved that, and the guy there said the woman that supplies the plants to them feeds them at every watering with a 1/4 strength solution of Miracle Gro. So I got some and have been doing the same (I use 1/2 tsp of Miracle Gro–the small end of the scoop that comes with the fertilizer–in the watering can I have, which holds 2 gallons of water). My bougies are in smallish clay pots on the west side of the house, so they need water every morning in this heat. And I feed them the Miracle Gro every morning. Seems to work pretty well. Yeah yeah, not organic, but it’s only for containers, and I go organic everywhere else….
