Japanese Maple - Disease or age?
I have an old and very large Japanese maple that appears healthy except on one branch. Do I removed the dead portion and seal the wound? Is this perhaps a natural progression for a 60 year old Japanese maple tree? Photos are attached. Joe Fallows
No it isn't a natural progression Joe. While there are numerous issues that can cause branch death, one stands out as most common in maples, verticillium wilt. You can read more about it at this link:
Most important as you see is a correct and positive diagnosis. The best way to
achieve that is with an onsite visit by a Certified Arborist, one who specializes in everything woody. You can find one or more Certified Arborists in your zip code at www.treesaregood.com Click on the Find an Arborist tab. Arborist evaluations are not expensive and gives the best chance of heading off future problems.
Or you could send a sample to Diagnostic Services for evaluation for a small fee: https://pestid.msu.edu/
Or you could wait it out and see what happens. Meanwhile, prune out the dead if you can and focus on keeping the plant healthy by watering during droughty periods and fertilizing in the spring. And no, do not seal the wound. Let the wound heal over naturally. Sealers interfere with that process and can become problematic.