It's your favorite shade tree. Or maybe you planted it to honor a loved one.
You want to save that ash.
Emerald ash borers have killed millions of ashes in Michigan, Ohio and Indiana. Efforts to contain the spread have failed. The tree killers showed up last year in northern Illinois. They haven't been found in Wisconsin yet, but many believe it's just a matter of time.
Rock, Walworth and Kenosha counties are considered a "red zone" because they're closest to the Illinois infestations, said Mike Maddox, horticulture specialist with the UW Extension in Rock County.
What can you do? Pesticides have helped keep ashes green in the face of emerald ash borer, at least for a while.
But under certain conditions, the state of Wisconsin is planning to cut down all the ash trees in a half-mile radius of an infestation. Your tree would be cut even if you had treated it, even if it appeared perfectly healthy.
That's why Maddox advises against treating trees.
A tree owner could gamble, however, on the possibility that the state's tree-removal money would run out before the cutters got around to his particular tree, or that the infestation is so widespread that the state couldn't afford eradicating all the ashes in a particular area.
"There is that outside chance, but that's depending on how much money you have at your disposal," Maddox said. "I don't recommend it."
Still, there's an argument to be made for treating ash trees. And now is a great time to make that decision, because mid-April is the best time to apply the most common home-use insecticide for this pest.
A U.S. Department of Agriculture official stressed that tree-owners should make their decision with eyes wide open.
Be an educated consumer and know the risks, said Sharon Lucik, spokeswoman the USDA's Animal and Plant Health Inspection Service.
Lucik said she handles all news inquiries about the federal emerald ash borer program. She is stationed near the borers' devastation zone in Michigan.
Lucik said she never tells a tree-owner not to treat, but she lays out the facts as she sees them, including:
-- Borers haven't been discovered in Wisconsin: "If it's not in the area, why would you treat the tree?"
-- Chemical treatments don't do much good in areas where the population of emerald ash borers is high. If you treat your tree but your neighbors don't, your tree could be overwhelmed anyway.
-- Trees treated in Michigan have survived for a while, but the borer population has eventually overwhelmed them. However, the treatments have bought time, and sometimes that time is worth it to the tree owner.
-- Keeping a tree alive for a couple extra years might buy enough time for a cure to be developed.
-- "It's relatively inexpensive, and certainly if that's something you want to do, go ahead, but I also do indicate that a treated tree does not exempt that tree from a mandated cut," she said.
"When do you give up hope? I guess if that tree is near and dear to you, I would hang onto it as long as I could."
Treating ashes Root-feed chemical is common approach:
The most common home-use chemical to fight the emerald ash borer is imidacloprid. On store shelves, imidacloprid is contained in Bayer Advanced Garden Tree and Shrub Insect Control.
The chemical is mixed with water, and the mixture is poured on the ground to be absorbed by the roots.
The wormlike borer larvae, which develop under the bark, eat the poisoned tree tissues. Or, when they emerge as beetles, they eat the poisoned leaves.
The chemical is "relatively safe to non-target organisms such as mammals, birds and some groups of insects," according to the Purdue University Extension.
The UW Extension has this to say:
-- "Using insecticides preventatively to control EAB on ash trees is … only recommended within 10-12 miles from a confirmed EAB infestation." And so far, that means nowhere in Wisconsin.
-- "If your tree is located within an area designated for eradication, it may be removed by regulatory agencies even if it has been treated."
-- "Insecticide treatments are more effective on smaller trees, with a trunk diameter of less than 10 inches."
-- "If numerous untreated, infested ash trees are nearby, insecticides and other controls are less likely to protect trees."
-- "Once trees become infested, insecticides will be less effective even if trees are showing few EAB symptoms."
-- "It is still unclear if insecticides are enhancing tree survival or just delaying tree death."
-- "When using any pesticide, read and follow label directions, as required by law."
Ash-tree advice from Hoosier State:
The Purdue University Extension, which is dealing with areas already infested with emerald ash borer, has this advice for homeowners:
"Because pesticides must be applied yearly, they are best used to protect high-value trees or to keep individual ash alive until non-susceptible replacement trees are large enough to provide shade benefit.
"A severely compromised ash tree, regardless of the cause of its poor condition, is not a good candidate for preventative or curative treatment.
"Property owners should take the long-term cost of prevention into account … Since ash trees must be treated every year for an indefinite period, the cost of chemical protection may quickly exceed the cost of removing and replacing them."
