Emerald Ash Borer is here. Now what?

CRESCO - Emerald Ash Borer (EAB) is here, and it will kill your ash trees unless they are treated. That is what experts told 30 or so individuals who attended the informational meeting on July 12 at the Featherlite Center.

The first Howard County sighting of EAB was discovered in Cresco in mid-June on 3rd Ave. S.E.

Now that EAB has been found in Cresco, ash trees in a 15-mile radius of the town are at risk and should be addressed.

Four speakers explained the migration and infestation  of EABs and the future of ash trees in the United States and Howard County.

 

Signs of infestation

Mike Kintner Iowa Department of Agriculture and Land Stewardship (IDALS) said signs and symptoms of EAB include a canopy die back that starts at the top; woodpecker activity; bark splits; “D”-shaped exit holes; “S”-shaped galleries under the bark; feeding notches on edge of leaflets; and suckering or small branches that shoot up from the base of the tree.

Management

He went on to explain a little about the management of EAB. “Treatment is not practical for woodlands.” In addition research is being done on resistant trees as well as introducing parasitic wasps in five areas of Iowa.

Jason Walker, Iowa DNR District Forester, told the audience he saw first hand the devastation caused by EAB.  “I was in Chicago walking down Michigan Ave. It was still fall, but every tree was stone cold dead. They were all ash trees.” 

There was no way the city could take care of the trees, and they all died.

Walker’s suggestion to prevent this from happening in towns and private properties is diversity. “If you are planting five trees, plant five different trees. After Dutch Elm Disease, they said to plant ash, and now see where we’re at.”

He also recommended to stay away from maples and stick to native species including oaks, several types of spruce and scotch pine.

Cresco’s Public Works Director, Rod Freidhof, agreed. “Cresco is about 60 percent maple. We are not allowing residents to plant maples.”

Treatment

Dr. Donald Lewis of the Entomology Department at Iowa State University gave three strategies for ash tree owners now that EAB has been found in the area. 

1. Do nothing. Wait and see. The tree will die.

2. Remove a failing/declining ash tree and replace with another species.

3. Use preventative insecticides and treatments.

Lewis explained treatment is certainly an option, especially for trees a home owner wants to save, but it will cost a person.

“For trees with a 20-inch diameter or less, a home owner can treat the tree. If larger, you need a certified applicator.” Lewis went on to say treatments for the larger trees by injection would cost, on average, $15 per diameter inch every other year. That may sound high, but the expert said prices have decreased.

He also assured those present that all treatment methods do work, regardless of what their applicator tells them. 

Currently it is recommended to treat every other year, but it may come to treating every three or four years as products and technology improve. In addition, treatments should take place in the spring.

He does not recommend canopy sprays. In addition, treatment should not be used within 25 feet of flowering plants.

How many ash trees in area?

Many towns and rural areas went with ash to replace trees devastated by Dutch Elm Disease.

According to research done for the Urban Forest  Management Plan conducted by Northeast Iowa Resource Conservation & Development, several communities in Howard County had a tree count completed. Results for ash trees include:

Chester: 45.5 percent

Cresco: 18 percent 

Lime Springs: 23 percent

Ridgeway, Winneshiek County: 10 percent

Other towns in Howard County estimated the number of ash trees.

Elma: 30 total

Protivin: 15 total

Riceville: No response

What to expect locally

Freidhof said of the city of Cresco, “In 2010, we did an inventory and found we had approximately 500 ash trees. We have started to take them down and now have 420-430.” 

The plan is to cut down 50-75 trees per year, starting by the school and hospital first. 

One of the hard-hit areas will be 3rd St. East, where four out of five trees appear to be ash.

The city feels Beadle Park has some important ash trees and plans to treat one-third of these. There are also 1-2 trees in East Park that will be saved.

Freidhof stated the city will not treat boulevard trees, but property owners can if they want to. “If you are treating your tree, let us know. We don’t want to cut down a tree that is being treated.”

In regards to trees not on the boulevard, Freidhof urged property owners to start cutting them down. “The City has an ordinance — if you have a diseased tree, you have to take it down.”

Freidhof said after Dutch Elm Disease wiped out that species, the City of Cresco replaced about 100 trees per year. Recently the number has dropped to around 40 trees being planted. “In the next 5-10 years, I can see us planting 100-120 per year.”

The best way to prevent spreading the EAB is not to move firewood. Burn it where you bought it or have it. Naturally EAB moves at less than two miles a year. A vehicle transferring firewood moves much faster than that!

For more information go to http://www.extension.iastate.edu/psep/emeraldashborer.html or call Sue Barnes at ISU Extension and Outreach in Howard County at 563-547-3001.