cutting petunias back

My petunias are getting leggy. I heard you can cut them back, but how far back on the stem do you cut before it'd to far and it won't grow back.

Jordung,
I just cut some [a few weeks ago] to about 3-4 inches. I noticed thay are beginning to re-bloom.

beerygirl, thanks for the info, will do.

Jordung, Petunias are my favorite annual because I am so successful with them. I have 50 years of experience. File this information away for next year: Plant petunias after frost is no longer a danger (mid-May for me) and cut the plants in half around the end of June, beginning of July (aafter 6 weeks). I always cut back to just above a budding leaf on each branch. When your new plant gets to be about 7" tall, pinch off its top. This will force the plant to "bush" or grown more branches which in turn makes the plant become round and full. Then you continue this process throughout the plant's growth cycle. When new branches of a petunia get to be 6-7" long, pinch off the ends, forcing each branch to make more branches. This is how you avoid your plant becoming leggy. Many people hate to pinch the ends off because they see flowers forming, but it is quite necessary if you want a bushy plant with many, many more flowers than you would have had if you hadn't pinched the branch back. Also, it is imperative that every few days you deadhead (remove) old, spent blooms because the plant starts thinking: "I need to ripen the seeds inside this old bloom so I can propagate myself." But if you pinch off the old blooms and remove the seed pod, the plant will start thinking: "I need to make more flowers, so I will have seeds to propagate myself." Eliminate the old blooms and its seed pod, and the plant will make more flowers. I promise you! And of course, you must water but not overwater. Don't you just love that kind of advice? But you will soon learn what's enough and not too much. Takes practice. Good luck to you.