Pruning a Vine Maple

[Dean Riechman]

Hello everyone,

I have a vine maple (Acer circinatum) that is about 15' tall with 5 stems that almost touch at the base. The stems are about 4-5" dia each. It's growing behind a retaining wall and probably doesn't get enough water in the summer. Two of the stems died early this summer while I was away for a while when it was unusually hot. The other 3 survived and appear to be ok. Could someone please help me with pruning away the 2 dead stems?

1) First, I assume the stems are all connected somehow underground to common roots so that what I do to one affects them all. Is that right? Otherwise the rest of the questions won't matter :)

2) Is this a good time to remove them, or should I wait until later in the winter? I'm near Portland, OR and the leaves are off now.

3) I want to make the first cut high to reduce the weight and then make a final cut. Should the final cut be as close to the ground as possible or is there a best place to cut them?

4) Is it necessary to treat the exposed wood?

Thanks for any help.

Dean Riechman

[Brian]

[Dean Riechman]

Thank you, Brian. I will cut the trunks at about 6" and leave the wood untreated as you suggested.

I believe it is at least 25 years old. I have two of them and they both seem to have peaked at about the same height. Growing conditions may not be ideal though.

It was probably pruned or trained so the trunks grew in a more-or-less straight line to fit in the small space. I believe that it always had multiple trunks (stems, branches?) though. They grow natively here, and I see some in the woods that have a single trunk and others with multiple trunks. Both have identical leaves and samaras so I am not sure is they are varieties of the species or if some condition triggers the different behavior.

Best regards, Dean

[Derryl Killan]

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 derrylkillanshaw.ca

[sam]

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