Tree Management Questions or Concerns

Please contact: Chris Domina, Manager of the grounds at x2829

What is a 'hazardous' tree?

A hazardous tree is 'a tree with structural defects likely to cause failure of all or part of the tree, which could strike a ‘target.’ A target can be a vehicle, building, or a place where people gather such as a park bench, picnic table, street, or backyard.'1

In context of this quote, 'failure' of a tree refers to a tree not being able to support all or part of itself upright anymore, at which point all or part of the tree may fall over and hurt passersby or damage property.

In context of this quote, 'structural defects' may include poorly healed trunk wounds, which indicate areas of unhealthy tissue that are susceptible to infection; fungal or bacterial infections that render the wood soft, spongy or hollow; cracks in the trunk, which indicate areas of structural weakness, as well as increases susceptibility to infection; cavities in the tree, which significantly decrease tree strength, may collect water and cause rot, and increases susceptibility to infection. In the context of the above quote, 'structural defects' weaken the overall strength of the tree trunk, branches and roots to the point where the tree may fail, and fall over.

Why does the Botanic Garden and Facilities Management remove campus trees?

Campus trees that have been repeatedly evaluated as 'hazardous' by the Director of the Botanic Garden and a consulting arborist are removed to prevent accidents from occurring on campus. Our desire is to maintain a safe campus. This is the only reason we are removing these hazardous trees. Already, the campus community has had some near misses with falling limbs and trees. The Botanic Garden and Facilities Management must follow the safe course of action and remove diseased, decaying, structurally unsafe, hazardous trees.

1 Minnesota Department of Natural Resources, and USDA Forest Service. 1996. How to Recognize Hazardous Defects in Trees. USDA Forest Service NA-FR-01-96. 20 pp.

Quercus alba, White Oak, near Mary Lyon's grave was removed when testing indicated the interior of the tree was hollow

Quercus alba, White Oak, near Mary Lyon's grave was removed when testing indicated the interior of the tree was hollow.

Hazardous Pin Oak, Quercus palustris, removed from Skinner Green near Blanchard

Hazardous Pin Oak, Quercus palustris, removed from Skinner Green near Blanchard