If your sedums are getting ragged looking like this, you can blame the birds. In summer, birds seeking water will begin eating the juicy, succulent leaves of sedum. Maybe they like the taste* too, because the damage has been seen with available water in close proximity. Fortunately, the birds usually leave the flower buds alone to bloom in late summer, but the whole plant certainly looks worse for wear for the rest of the summer.

If birds eat your sedums every year, one solution is to cover your sedum with bird netting for a good part of the summer. You may also have luck with hologram tape or other visual repellents. Spray-on repellents don't work on birds since they have little or no sense of taste or smell.** 

*Actually, probably not...
**...and that's why