Take care of city trees this fall

As fall approaches, there are a few ways folks can help keep Minneapolis’ trees healthy and thriving. Emerald ash borers are now dormant until spring, so it is safe to prune ash trees. Also, it’s still important to make sure your yard and boulevard trees are getting enough water. Those trees continue to need watering any time it doesn’t rain an inch in a week.

Ash trees

As fall puts an end to the growing season, a beetle that attacks and kills ash trees is going dormant until spring. The emerald ash borer is present in Minneapolis and is inactive between Labor Day and May 1 most years. If you have an ash tree in your yard that needs pruning or if you would like to take it down, now through May 1 is the best time.

The emerald ash borer is a major concern because it has caused the deaths of millions of ash trees in 15 states, and approximately 20 percent of the tree canopy in Minneapolis consists of ash trees. The Minnesota Department of Agriculture has issued a state quarantine on firewood, ash trees, and ash tree products in Hennepin, Ramsey, Houston and Winona counties to slow the spread of emerald ash borer.

If you have space in your yard to plant a tree, you can still plant one in the fall. Research has proven that trees are a valuable investment and improve urban quality of life. Healthy trees are beautiful, increase property values, help improve air quality, reduce greenhouse gases by absorbing carbon dioxide, save energy, keep the city cooler, provide homes for wildlife and help manage stormwater.

Not sure if you have an ash tree in your yard? See ash tree identification tips here.

For more information on emerald ash borers, visit the Minnesota Department of Agriculture emerald ash borer Web page or the Minneapolis Park and Recreation Board’s emerald ash borer Web page.

Yard and boulevard trees need an inch of water every week

Our yard and boulevard trees need an inch of water every week throughout the spring, summer and fall. After a dry summer and nine years of drought, trees need help to recover. Past years of high temperatures and drought conditions are a problem even for otherwise healthy trees and put them at serious risk of long-term damage.

Extended drought conditions can make trees vulnerable to insects and disease and cause permanent damage to young and old trees alike. Young trees three to five years old are especially susceptible.

An effective way for residents to water a tree is to turn on a slow stream of water (just so the hose is weeping) for a few hours. Watering in the evening after dinner time is most effective since it minimizes evaporation, and trees tend to take most of their water during the night. Watering should continue until trees have dropped their leaves and reached full dormancy. Normally this occurs in early to mid-October.

For information on tree care and the urban forest, call the Park Board’s Forestry Department at 612-313-7710, email forestry@minneapolisparks.org or visit www.minneapolisparks.org/trees.

If you hire a tree servicing company to prune a tree, make sure to use a company licensed in Minneapolis to ensure that the tree gets the right care. For more information and a list of licensed tree servicers, visit www.minneapolismn.gov/licensing/business-licensing_treeservice.

Taking care of our trees means protecting our Minneapolis quality of life. Research proves that healthy trees are beautiful, increase property values, help improve air quality, reduce greenhouse gases by absorbing carbon dioxide, save energy, keep the city cooler, provide homes for wildlife and help manage stormwater.

Published Sep. 17, 2012