Question
I live in South Eastern Pennsylvania, near borders of Maryland and Delaware. I have two types of pussy willow Chinese and normal.
When and how far back to the main stems is it best  to prune these shrubs/trees?

Answer
Hello William

If your pussy-willows [Salix] are the ordinary shrub or tree type, and you are not growing them for the winter display provided by their stems, winter is the best time to prune them.  Take out crossed,  wayward and dead stems completely, cutting close to the base of the plant.  If you really do need to make the plant(s) smaller, cut back stems to form a neat shape the size you need.  This type of pruning should be carried out in late winter or early spring - you may find that you don't need to prune more than every three years.

If any of your plant are being grown for the winter display I mentioned earlier you will need to prune them every spring by cutting the growth down to within 2 or 3 buds from the base.  This sounds (and looks) drastic, but it really is the only way to get those colored stems!

I hope this has been helpful.

Gill