Yard and Garden: Handling Problems With Landscape Trees

July 27, 2017, 9:49 am | Richard Jauron, Greg Wallace

AMES, Iowa – Trees add value and beauty to any landscape, and can provide shade, protection and much more. When they’re afflicted with unknown ailments, there’s natural reason for concern. What can be done?

ISU Extension and Outreach horticulturists can help answer your questions about issues with trees. 

My sycamore tree is losing chunks of bark. Is something wrong with the tree? 

Shedding bark on some trees is a completely normal development. The bark of most young trees is smooth and thin. As the tree grows, the bark layer thickens with the outermost tissue eventually dying. Continued growth pushes the bark outward, sometimes causing the outer layers to crack. On some trees, the outer dead layers peel and drop off, revealing the inner layers of bark. 

Shedding or peeling bark is characteristic of trees such as sycamore, redbud, paperbark maple, shagbark hickory and birch. The grayish brown bark on a large sycamore tree, for example, flakes off in irregular blotches, revealing a cream or whitish gray inner bark. The loss of the outer layers of bark on sycamores is completely normal.


A tree in my yard is producing suckers. Is there a way to stop the tree from suckering?

Aspen, white poplar, chokecherry, black locust, Kentucky coffeetree, persimmon and several other trees send up shoots or suckers from their roots. In their natural habitat, suckering trees form colonies. Unfortunately, nothing can be done to prevent these trees from suckering.

The best way to deal with sucker growth is to periodically remove them at ground level with a pruning shears. Mowing them off with lawnmower is also effective, but the sharp-pointed stubs might be a safety hazard to children playing in the yard. Herbicides should not be applied to the suckers as a herbicide may damage or kill the sucker-producing tree.

There are wart-like growths on the undersides of the leaves on my hackberry. What are they?

The wart-like growths on the hackberry leaves are galls. Galls are abnormal growths of plant tissue induced to form by mites, insects or other small organisms. They are common on many trees.  

The gall found on hackberry leaves is referred to as the hackberry nipple gall. The gall is induced to form by a gnat-like psyllid. The hackberry nipple gall is so common on hackberries that its presence can be used to identify the tree.  

While galls may be unsightly, they do not cause serious harm to healthy trees. Preventive insecticide treatments are not necessary.  

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