The term old wood refers to any stem that the plant had last year, that survived winter and leafed out in Spring.

Hydrangeas that bloom on old wood produce invisible flower buds around July-August. These stay invisible and unopened until after the plant leafs out in Spring.

Stems that have not leafed out by mid-May and remain dried out can be safely pruned at ground level or so.

This post was edited by luis_pr on Fri, Jul 5, 13 at 20:27