Red Maple half dead - Ask Extension
one half of our red maple is dead. The other half is fine. It has been in that place for more than 15 years. We think the cedar is affecting it. W...
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Red Maple half dead #880246
Asked August 05, 2024, 12:32 PM EDT
one half of our red maple is dead. The other half is fine. It has been in that place for more than 15 years. We think the cedar is affecting it. We can cut the cedar branches back, however, do you think we actually need to move it to give it more unobstructed space. If so, what is the recommended space to allow. Is there any other suggestion? I have many more photos if you need them.
Anne Arundel County Maryland
Expert Response
The cedar is not responsible for the dieback on the Japanese Maple, though it's hard to tell what was. Our prime suspects include a girdling root, since the maple appears to be planted too deeply (or over-mulched), and an opportunistic infection like Botryosphaeria canker. (The linked page focuses on Rhododendron, but this pathogen can infect a wide range of other species when the opportunity arises.) Drought stress is one factor that can predispose plants to this kind of infection and dieback. Is the maple monitored for watering needs? Much of the 2023 growing season, plus this summer so far, has experienced drought, and maples prefer to remain more evenly moist. While some wood-boring insects (mostly beetles) can attack trees that are stressed and kill part of the canopy, we don't see evidence (at least from this distance) that they have damaged the trunk.
For now, the dead branches will need to be cut off, using a pruning saw for a clean cut. Shade from the cedar might discourage regrowth on that side of the tree from filling back in, though it's hard to say for certain, since Japanese Maple does have decent tolerance for partial shade. In either case, new growth would not be expected until next spring, though occasionally some new sprouts can appear this time of year. (Don't encourage rapid regrowth with fertilizer, though, as the later in the summer new shoots develop, the more at-risk they would be for winter damage.)
Miri
For now, the dead branches will need to be cut off, using a pruning saw for a clean cut. Shade from the cedar might discourage regrowth on that side of the tree from filling back in, though it's hard to say for certain, since Japanese Maple does have decent tolerance for partial shade. In either case, new growth would not be expected until next spring, though occasionally some new sprouts can appear this time of year. (Don't encourage rapid regrowth with fertilizer, though, as the later in the summer new shoots develop, the more at-risk they would be for winter damage.)
Miri
