Just cut the stems back to where the flowers began growing. Don't leave less than 6 inches on the plant or it may stress out and die. You can see new stems waiting to grow where the leaves meet the stem. Make sure they are watered regularly and fertilize with half strength Miracle Grow. That's my method. There are many threads on this topic. Just click on search in the annuals forum and type in petunias. Enjoy!

Thanks so much for the tip! I did notice a few other threads...after I posted. Thanks again!

My Petunias in my window boxes on my deck are starting to look dreadful too! They are very leggy, leaves are starting to turn a little brown at the bottoms and a lot of the blossoms have holes in them as if bugs are eating them, although I don't see any bugs! I ended up cutting them all back to about 5 or 6 inches. Not sure why I did this but I just got really frustrated right before I left for vacation the week before last and cut them all off! I figured I wouldn't be around to deadhead them and they would look even worse when I came home. They still don't look too good, I figure it's just the end of the season for them and me! It's a shame because they really were so pretty. At least I enjoyed them for almost 3 months!

Linda,

Water your petunias well, fertilize with a 15-30-15, then sprinkle with Dipel. Those little holes in the blossoms are caused by cabbage worms and Dipel (or BT) will take care of them. In 2 weeks they'll be going gangbusters again!

Deanna