Derryl Killan wrote:

Hi Dean

Maples of all types will bleed sap profusely if pruned when dormant.
Wait for it to leaf out fully and then prune it.

If there is not a viable cambium (cut the bark with a sharp knife to
see if there is any green) and if there is none then go ahead and cut
the deadwood,

Derryl



Um, this is almost exactly opposite of true. Maples will bleed most
profusely when they're breaking dormancy - spring. I tie little string
markers all over my maples during winter, when I can best see their
branch structures, and then do all my pruning during their summer
dormancy - late July/early August - when I can best see how they'll look
with their leaves. I've never seen a drop of sap.

In most places, it's best to prune maples during the coldest time -
winter dormancy. I choose summer (which is relatively mild here) because
it's too wet during winter and I fear fungal invasions.

sam
pnw/Z8