Welcome to ATP, Sandra
Hope we can help you out. Pictures of your planting area might give us a clue or two.
First thing I'd say is planting anything that gets the blazing afternoon sun like that, I'd give them some kind of temporary shade for a couple of weeks after planting. Once they start putting up new top growth, that means they're growing some roots, too.
Any way you can rig up a piece of shade cloth, or even make a tent with an old sheet or something? ( I know, your neighbors will really love it, right?) Shade cloth is pretty cheap and comes in dark colors . . .
Maybe wait another month or so to plant anything more, being as it's the hottest possible time of year right now. If you're buying transplants, splurge on the 3in. or 4in. pots rather than buying little 4 or 6 cell packs of baby plants. Better yet, gallon size. They'll have more roots, and more soil around them as well. A little plant with an ounce of soil and roots around it is just going to fry in the July heat unless you stand over them with the hose all afternoon. Even the big transplants need good, deep watering every morning if the weather's hot.
Mulch is another thing that will keep the roots of your new transplants cooler and more moist. Don't use rocks or rubber mulch ever! They just cause a lot more problems than they cure. Wood chip mulch is far and away the better choice.
