Question
Rather than have to list all of the plants I have, which are many, could you just tell me which plants should not be cut down in the fall for zone 5.  Thank you for your assistance.

Answer
Hi Phyllis,
Thanx for your question.  In general, most perennial plants can be cut back to the ground once the foliage has withered and started turning brown, such as peonies, hollyhock, black-eyed Susan, lavender, hardy hibiscus.  Some flowering shrubs like hibiscus should only be pruned back right after they bloom and should not be cut back to the ground.  Any later pruning could mean no flowers next year because the blooming buds begin growing in the fall. If it's withered and fading and produces new growth in the spring, cut off the old and dispose of it.  I hope this helps.
Tom