"Jenny" wrote in message
...
Is there some web page that gives detailed information about which of
perennials and shrubs need to be cut back in fall and how to do it?


I'm not aware of any shrubs that need to be cut back. Sometimes people
prune shrubs to promote flowering, but it isn't a necessity. Of course
pruning some shrubs like azaleas in the fall will remove all the flower
buds. Pruning shrubs late in the fall can often stimulate grow that doesn't
have time to harden-off before winter hits. I

As for perennials, I'm also not aware of any that have to be cut back. I
see it as a housekeeping exercise, especially for perennials that are
diseased. Removing the dead parts after a couple of hard frosts will remove
spores of fungal diseases that could otherwise remain over the winter. I
generally leave my perennials as-is, with very little attention until late
winter/early spring. At that time, I go out and clean up the garden. I
think that leaving the perennials help them to self-mulch over winter. Some
perennials have interesting seed heads or pods and the dead plants can add
interest in the winter landscape. They can also provide shelter for
wildlife.