Then, can I bring my petunias back to life?
Without adequate water, petunias may cease blooming, or foliage may wilt and die, within a day or two during hot, dry weather. With quick intervention, petunias can often be revived. Cut back foliage on overly dried petunias to within several inches of the soil level.
how do you know if petunias are dead?
If the first frost of autumn has come and gone, your petunias are likely dead and won't be coming back. Check the stems -- if they feel squishy, slimy and brown, your flowers are goners.
Deadheading Petunias: How To Deadhead Petunia Flowers Unfortunately, those colorful blossoms die off quickly, leaving you the job of deadheading petunias. Only if you want to avoid straggly green stems without blooms for at least half of the season. Keep your garden colorful and productive by deadheading your petunias.