No need to go into details. Melissa at Xanthan has the deets if you care to explore the minutiae of our aberrant heat phenom.
But something weird always takes hold of me about this time in summer. A sort of crazed defiance. I know that October will come and it will be a gift. The heat will break and we will be in the midst of a beautiful world. I look forward to that, knowing that there will be surprises. There are always surprise in nature; something that has heretofore gone unremarked will suddenly stake its claim on the landscape. I remember one year, vitex abruptly turned up everywhere in purple and became the shrub of the moment. Or a row of previously overlooked grasses is overnight gripped with halo of pink mist in the sunset.
Meantime, here at Aurora, the big success stories in this summer have been the grays. All things gray seem to be stalwart performers in this heat: sage, germanders, powis artemisia, cottoneaster, and lavenders all are hanging in there valiantly in my heavy clay soil. And they are happy companions to the desert reliables—blue-gray agaves, yuccas, and prickly pear.
One other plant of note: the Pindo palm. If you have any desire for a palm and you're on clay, plant this. It's abso fab and growing like a mofo. Takes what little water I give it and appears to be quite content.