Why should I care about Emerald Ash Borer (EAB)?
All ash trees are susceptible to EAB and millions of ash trees have been killed in infested areas already. It’s estimated that townhome associations may have as many as 40 percent of their trees as ash trees. Minnesota has one of the highest volumes of ash on forestland in the U.S. with an estimated 867 million forestland ash trees, and ash is a prominent component of our urban forests as well.
How many trees do you have in your association? If you have 200 units and there’s two trees per unit including common areas, that could mean 160 ash trees. The potential economic and environmental impacts of losing these trees is substantial. The cost of removing and replacing a single tree can range from hundreds to thousands of dollars. In any case, knowing the number and size of ash trees will be helpful and setting reserves aside now for future tree replacements or treatments is a good idea.
How do I prepare for EAB affecting my association? You have two choices. You can learn to spot EAB on your own using the links below. The information also includes insecticide information that will teach someone in your association to treat the trees or contact a reputable tree/landscape company especially if there are any large ash trees. Some companies will perform an ash tree audit to see how many ashes you have. The three options available for your ash trees are
Remove the ash trees now and replace with a different tree so the landscape can continue to mature.
Treat the ash trees using an insecticide. The treatments may have to take place for the remainder of the tree’s life. This is probably too expensive for your entire association, but if you have large ash trees in prominent areas, these can’t really be replaced and treatments might be the best option.
Wait until the ash trees die, dispose of properly and replace later.
Emerald Ash Borer is in Minnesota
On May 14, 2009, EAB was confirmed as present in the South Saint Anthony Park neighborhood in St. Paul. EAB is a serious invasive tree pest, and consequently a quarantine has been placed on Ramsey, Hennepin, and Houston counties to help slow the spread of EAB to other areas.
What is EAB?
EAB is an insect that attacks and kills ash trees. The adults are small, iridescent green beetles that live outside of trees during the summer months. The larvae are grub or worm-like and live underneath the bark of ash trees. Trees are killed by the tunneling of the larvae under the tree’s bark.
Where is EAB?
EAB is native to eastern Asia but was discovered in Detroit, Michigan and Windsor, Ontario in 2002. Indications are it may have been introduced to this area as early 1990. EAB has been spread in ash firewood, nursery stock and possibly other ash materials to a number of new areas.
"Dealing with emerald ash borer is a new challenge for most Minnesotans,” said MDA Plant Protection Director Geir Friisoe. "In some cases people may not know when it makes sense to treat their trees and when it doesn’t, or what kind of treatment will work best for their situation. With so many options out there and so many factors to consider, we thought it would be helpful to provide homeowners with all the relevant information in one small package.”
"It’s not just a matter of picking the most effective option for your trees,” Friisoe said.
"There are potential water quality and human health concerns with some of these products if they are not used properly. We’re doing our best to get that information into the hands of homeowners, but ultimately the responsibility is theirs to read, understand and follow the label requirements.”
Available to download on MDA’s Web site at www.mda.state.mn.us/eab, the guide recommends that homeowners consider the following factors before moving forward with an insecticide treatment. Also on the right side of the website, there are links to an EAB treatment guide, FAQ’s and how to determine if you have EAB.
Identify if EAB is near – treatments are only advised for trees within about 15 miles of known infestations.
Consider removing and replacing small and struggling ash tree – the cost of replacing these trees may be less than the cost of repeated treatments over the years.
Check the calendar – treatments are most effective from mid-April through June.
Have a professional treat large ash trees – do-it-yourself products are generally less effective on trees larger than 48 inches in circumference or 15 inches in diameter.
Contact a certified arborist or city forester before treating your trees – some communities have special restrictions or requirements.