Question
Live in Huntington, L.I.  My husband wants to cut back his hibiscus -would this damage it or help it.  He also thinks he can divide it into two plants.  What do you think?

Answer
Your Hibiscus -- this is a Hardy Hibiscus?  Perhaps a Rose of Sharon?

PRUNING Hardy Outdoor Hibiscus right now is asking for trouble.  You stimulate growth, the new growth is too tender to take on Winter, and the branch goes kaput.  Enough of that, and you're looking at Hibiscus Compost.

Dividing Hibiscus is indeed an option.  Your husband is right.

Michigan retailer Hallsons Gardens tells it like it is:  'Propagate younger clumps by digging and dividing in the Spring, but older plants may become so large you would need to lift them with a backhoe!  You may also take stem cuttings, which root quickly, in early Summer.'

Here's the URL:

http://www.perennialnursery.com/plantinfo/hibiscus.html

Now, this is not the same as 'cutting back' a plant.  This is called 'dividing'.  If your husband wants to DIVIDE the shrub, Autumn is the perfect time of year.  Reason being, roots are going dormant and despite the unavoidable damage this is a painless procedure.  In Spring, root hairs will be re-newed as the shrub returns from dormancy.

No fertilizing, please.  And wrapping with Burlap would raise the odds of survival.  Mound with soil to reinforce Winter survivability.  Thanks for writing; any questions, I'm here.