Green digest: Elf Tree gets protection

Elf Tree, an ash, gets protected from borer

FULTON — Many who live in Southwest or enjoy a stroll around Lake Harriet like to believe there’s something magical about a certain tree on the lake’s south shore.

But magic alone may not be enough to protect the Elf Tree, one of an estimated 190,000 Minneapolis ash trees threatened by emerald ash borer, an invasive Asian beetle. So, in July, local nonprofit People for Parks paid about $175 for its first injection with an insecticide that is purported to protect ash trees from emerald ash borer for about two years.

Jim Bixby, an injection care specialist with Rainbow Treecare, prepared the Elf Tree for the treatment by drilling four holes into its base — right around the tiny door where, for the better part of 20 years, the young and curious have corresponded with “Mr. Little Guy” by letter.

“The chemical is safe for amphibians — and I hope elves, too,” Bixby quipped as he readied an injection of TREE-äge, a product whose active ingredient is the pesticide emamectin benzoate. A 2009 North Central Insect Pest Management Center report cited studies by Michigan State University and Ohio State University showing it is one of the most effective treatments for controlling emerald ash borer.

Only ash trees face any danger from the beetle, whose larvae burrow beneath the trees’ bark, cutting off the flow of water and nutrients. Adults, metallic green and just smaller than a penny, can travel up to two miles per year on their own, but are often spread when infested wood is transported out of quarantined areas, such as Hennepin County.

The bug is blamed for killing tens of millions of trees in the U.S. and Canada since it was first found near Detroit in 2002. Arborists confirmed its arrival in Minnesota in 2009 and in Minneapolis — where one-fifth of all trees are ash — just last year.

Paying for tree injections is nothing new for People for the Parks, founded in 1977 in response to the Dutch elm disease epidemic. But this was the first time it paid to protect an ash, said Felicity Britton, vice president of People for the Parks.

Unlike the treatments designed to protect healthy elm trees against Dutch elm disease, products used to keep away or kill emerald ash borer can be applied “therapeutically,” Bixby said — meaning there is some hope to save trees after infestation.

Rainbow Treecare arborist Scott Henke estimated his company had treated 1,500 to 2,000 metro-area ash trees in the two to three years. Like other tree specialists, Henke expected the number of infestations to start off slowly and then “explode,” as they have in other parts of the country.

Asked if it was worth it to preserve certain trees through what could be years of ash die-offs, Henke responded: “I think so, but it is really going to be the prize trees, the trees they can’t replace.”

Those seeking to protect ash trees are advised to research treatment options before deciding on a course of action. A good place to start is emeraldashborer.info, a website produced by the U.S. Forest Service in collaboration with several Midwestern universities.

Bixby did not find any signs of infestation during a quick inspection of the Elf Tree. He measured its trunk diameter at breast height — about 14 inches — to calculate the correct dosage, and noted a few dead branches in the tree’s canopy.

“It may be a little stressed,” he allowed, but said the tree was otherwise in good health.

That’s good news for the elf.

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Nominate a “watershed hero”

Nominations for Minnehaha Creek Watershed District’s 2011 Watershed Heroes Awards are due by Aug. 12.

The awards, given annually, recognize individuals, businesses, government agencies and organizations for their efforts to protect local waters. The winners in seven awards categories will be recognized in an Oct. 20 ceremony at the Bayview Event Center in Excelsior.

The district protects and manages water resources within a 181-square-mile watershed that includes Minnehaha Creek and the Chain of Lakes.

A list of awards categories and instructions for nominating a Watershed Hero are available on the watershed district’s website, minnehahacreek.org.

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Go green for National Night Out

The city urged block club leaders planning National Night Out events for the Aug. 2 celebration to green their block parties by limiting waste and boosting recycling.

Suggestions included asking neighbors to bring their own reusable plates, cups and utensils, buying condiments in bulk, sending invitations by e-mail instead of on paper, serving local foods when possible and setting out recycling containers for clean-up. For more green block party ideas, download the tip sheet available at ci.minneapolis.mn.us/nno/Green-Block-Party.pdf.

The really ambitious looking to reuse, recycle or compost all the waste at their block party can find tips for hosting a zero-waste event at www.ci.minneapolis.mn.us/solid-waste/garbage-zero-hero.asp.

Reach Dylan Thomas at [email protected]