Our apx 15 yr old sugar maple is showing signs of decline. Leaves are very...

Asked June 27, 2014, 12:42 AM EDT

Our apx 15 yr old sugar maple is showing signs of decline. Leaves are very "thin" on the tree, dead branches are scattered throughout. The leaves have not fallen off, they just didn't grow in nice & thick & lush as usual. Is this because of the excessive rainfall I wonder ? This tree has flourished in all years past... it's sad to see it so "sick" looking. Wondering if other Twin Citians are having similar problems ? thanks much for your opinion, Michelle McQuillen I can send a photo if it would help.

Scott County Minnesota

1 Response

Thank you for your question.

Acer sacchrum, the sugar maple, is a valued landscape tree for its beautiful fall color and sweet sap gathered for maple syrup. Dieback, a thin canopy, premature color change, and leaf drop are common symptoms of environmental stress caused by compacted soils, hot dry sites, flood damage, winter damage and competition with other plants such as turf . Sometimes it may take several years before this becomes evident; sometimes it can occur quickly. Trees are sometimes planted too deeply as well, causing a tree's roots to girdle and eventually can choke a plant. The plant may show early coor change, dieback, stunted growth, symptoms of being water-stressed (lack of water), and excessive winter damage like frost cracks. Other reasons may include sapwood rot, verticillium wilt, cankers, scale, and rots. Our online tool "What's wrong with my plant?" provides information on these issues and diseases here: http://www.extension.umn.edu/garden/diagnose/plant/deciduous/maple/branchesdead.html

Some basic management practices can help you provide optimal growing conditions for your trees. Mulch trees with 6-ft rings to hold moisture, protect roots, and prevent damage to trunks and roots from mechanical damage like lawn mowers and weed whips. Have you trees pruned professionally by a licensed arborist. Find one close to you here: http://www.isa-arbor.com/findanarborist/arboristsearch.aspx Water trees, shrubs and flower when dry conditions exists. It is especially important to water woody plants like trees and shrubs as late in the season as possible to help prevent desiccation during the long dry winters.

Best of luck to you and thank you for contacting Ask an Expert.