In high heat plants shut down to conserve energy. When it cools down they should perk back up.Do not fertilize while it stay this hot.
It will come back better than before. Looks a little pathetic and stressed right now, but give it enough water during the heat (just don't over-water...and no fertilizer right now like Donna mentioned) and it should bounce back fine once it cools off a bit. Petunias are touchy, but very forgiving. I love 'em!
When you water use the finger in the soil method of determining when to water, not a schedule. Stick a finger in the soil, if the soil is still moist in that top three inches, don't water. The roots are down in the soil, not growing just below the surface so if the surface is dry that doesn't necessarily mean the roots are dry. The more water you add to that lower level of soil, the more it accumulates and soon the roots drown and the plant dies. Perennials will go dormant during a really hot spell, then come back (unless you didn't water during that time) with a flush of new growth when fall cools down or next spring. Annuals do not go dormant but they do either stop blooming and growing or blooming and growing slows way down, it's an act of self preservation.
I agree with all the others AND I have one that looks even worse. Let it cool down a little and it should do fine. I brought my mom's home and trimmed them back by 1/2 and they are looking marvelous. They just needed pinched and a little time to re grow.
Elishasmama, I noticed my ugly petunia basket has mildew on it....check yours closely to make sure the leaves look healthy.It may need a fungicide to get it going again. I sprinkled on a copper dust product and I notice it is growing better.
