Minnesota seeing growing number of sick maple trees

September 17, 2017 GMT

MINNEAPOLIS (AP) — Many maple trees across the Minneapolis area are sick and have been turning color and dropping leaves before the official start of autumn.

Alan Branhagen is the director of operations at the Minnesota Landscape Arboretum. He told the Star Tribune that the arboretum has been flooded with questions about the early leaf drop.

“It’s becoming epidemic,” he said of the distressed, yellow-leafed maples, some already with bare branches that have raised curiosity and concern this growing season.


Branhagen said rot may be causing the maples to decline. Irrigation systems and thick mulch can result in conditions that are too soggy for the trees.

“Sugar maples like it moist but not wet,” Branhagen said.

Certified arborist Travis McDonald said many of the trees are suffering from root girdling, which is when roots grow around each other and prevent nutrients from going to the tree.

Maples are particularly susceptible to girdling because they have a fast-growing and shallow root system.

Many trees that are sold at nurseries and garden centers are grown in containers instead of fields, which causes roots to become tangled before the tree is purchased and planted.

The increase in distressed maples may be because many of the early container maples planted in the area are now mature, Branhagen said.

Many distressed maples lack stability and therefore should be removed because they’re more prone to windfall, Branhagen said.

Residents with distressed trees should consult a tree expert to diagnose the problem and see if the tree can be saved, McDonald said.


Information from: Star Tribune, http://www.startribune.com