We mulch our entire borders. Yikes it's really expensive but looks so good! The good thing is that you only have to do a huge mulching one year, the next you fill in, and then the next it's back to a big mulch again. We get the black shredded kind. Very few of our neighbors mulch which surprised me. Every place else I've ever lived everyone always mulched.
We put down 4 yards but probably need another 3 good yards to finish the back yard. The one exception is right by the patio where we hang our bird feeder. So many sunflower seed hulls (black) drop down I just sweep them in the whole area around it and call it my free "birdseed mulch".
Edited by Stormy - 6/15/12 at 4:50pm