With nearly 18,000 ash trees on city property and another 22,000 on private property, Burnsville could lose a lot of leaf cover when the destructive emerald ash borer arrives.

A city survey has found 3,000 ash trees on boulevards, 900 in parks and another 14,000 in city woodland areas.

With that many trees at risk — even though the metallic green beetle has not yet been found south of the Minnesota River — the Burnsville City Council last week accepted the ash borer's arrival as inevitable and budgeted $3.5 million to fight it.

With that money, the city will inject 2,865 of the biggest, healthiest park and boulevard ash trees with insecticide to ward off the beetles. It will also remove 1,107 less healthy ash trees before they die and become a problem.

Half of those removed would be replaced with 600 new trees. The 10-year plan would start in 2014, or this year if the borers are found this summer.

The estimated 14,000 ash trees growing in Burnsville's woodland areas would be left to the effects of the beetles and removed only if they became a threat to public safety, said Terry Schulz, the city's director of parks, recreation and natural resources.

To help residents cope with beetle-infested trees in their yards, Schulz said the city will extend to homeowners the price contractors give the city for tree injections.

The city plans to hire someone to be a go-to person for residents' questions and problems, and it will post answers to most frequently asked questions on the city website, including: "How to determine if your tree is worth protecting."

"We are going to get a lot of phone calls and a lot of interest from our residents," Schulz predicted.

The city hopes residents will plant and water new boulevard trees and volunteer to pay for the treatment of some ash trees on the boulevards in front of their homes.

"Treating is something we promote as a city," said Council Member Dan Kealey. "The trees that we have are an important part of the character of the city."

The beetle larvae of the emerald ash borer, an invasive species from Asia, burrow under the bark and kill every tree they infect unless the tree is treated, Schulz said.

The insect is making its way across the country from east to west and already has been found in Minnesota as close to Burnsville as Fort Snelling, just 8 miles away.

Experience with the borer in other states has helped Minnesota prepare, Schulz said. "We know now that treatment of ash trees is very effective and becoming more cost effective."

It would cost about $750 to remove an ash tree and $75 a year for 10 years to protect it, Schulz said. "You can treat it for 10 years for the cost of taking it down."

The city plans to treat its chosen trees for 10 years and after that may be able to treat them every six years, he said.

City of trees

Burnsville started as farmland with no trees and has become a city of trees, said Mayor Elizabeth Kautz. "I would hate to see this little bug destroy it."

The budget for the selected plan will allow replacement of 50 percent of the trees cut down on city property. Council Member Mary Sherry said she would like to consider spending another $100,000 and replace all 1,107 trees to be removed.

Trees are precious, Sherry said. "I would hope we can encourage as many citizens as possible to voluntarily go to our tree sale to get a tree to plant."

The sale is scheduled from 7:30 to 10:30 a.m. April 27 at 75 Civic Center Parkway across from City Hall. Prices will range from $25 to $50 for bare-root trees.

To Sherry's point about replacing every tree the city takes down, Schulz said there is time to make a decision to plant more trees as the program unfolds. He said the plan will be reviewed again in 2018.