Is it recommended one prune to size and shape in the late fall or early spring?
(At some point in the spring it will be too late to prune and get blooms?)
When to prune Hydrangeas that bloom only on new wood?
Depends on the type. Macrophyllas (mop head and lace cap) should have been pruned shortly they bloomed and peaked as the new buds are being formed through summer. Paniculatas and Arborescens can be pruned in fall, early spring since they bloom on new wood. Naturally you can prune when you want to if you don't mind sacrificing blooms next year.
Thanks for the post hcmcdole. I am thinking that in my neck of the woods maybe any fall pruning should be postponed to spring as winter snow and ice can lead to branch damage that then can be 'corrected' in the following spring.
The hydrangea I used to prune back to the trunk each year was PG. I haven't done that in a few years and the bloom production has fallen off. I guess I should get back to that tactic on this particular hydrangea. I would prune it in late fall or early spring and it always bloomed great.