Don't cut down ash trees just yet

In the campaign against the emerald ash borer, state officials want Twin Cities residents to hear this message loud and clear: Cutting down ash trees could actually make things worse.

The emerald ash borer has killed millions of ash trees in Eastern United States. Minnesota's first infestation was detected a week ago in St. Paul.

For now, the state Department of Agriculture said Thursday that homeowners should monitor their trees and contact experts if they have questions about signs of insect damage.

However, the department emphasized in a news release, "cutting down ash trees is not immediately necessary -- and could accelerate the spread ... if an infested tree is not disposed of properly."

Geir Friisoe, the department's plant protection division director, said homeowners should look for the tell-tale signs of infestation, which include: ailing leaves in the upper one-third of the tree's branches, heavy woodpecker activity, D-shaped exit holes in the bark, S-shaped tunnels under the bark or water shoots up the trunk.

"It's important for homeowners to know what to look for and to monitor ash trees on their property" for signs of infestation, Friisoe said. "Lack of understanding ... can lead to improper treatments or needless applications of pesticides."

The metallic-green adult beetles are a half-inch long and active from May to September.

State and local officials are emphasizing that they are just beginning to assess the extent of the emerald ash borer infestation. They told residents at a public meeting Wednesday in St. Paul, near the initial detection, that they need to know more before they develop plans for dealing with it, including disposal of infested trees.

Minnesota has about 900 million ash trees, second most of any state. There are about 300,000 in Minneapolis and St. Paul.

Officials are also reminding residents that they should not move ash from place to place, because that is believed to be how the ash borer has spread quickly across the Midwest. In particular, with a holiday weekend approaching, they are reminding residents not to carry firewood with them camping, but to buy and burn firewood where they camp.

Movement of ash trees or wood into and out of Ramsey and Hennepin Counties has been prohibited since last week's identification of the ash borer. Ash chipped into pieces 1 inch in diameter or smaller is regarded as bug-free and safe for mulching.

For more information, visit www.mda.state.mn.us or call 651-201-6684 in the metro area or 1-888-545-6684 outstate.

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