Click here for an overview of Emerald Ash Borer and a related link.
Emerald Ash Borer (EAB) has moved rapidly since its discovery in Michigan in 2002. It has been confirmed in Iowa; however, it is located in an island in the Mississippi River in Allamakee County. While there are no confirmed reports of EAB further into the state, it is highly likely that it is elsewhere in Iowa, but it simply has not been found yet. Given the high percentage of Ash trees in Cedar Rapids, and the overall condition of the majority of them, the decision was made to start proactively reducing the population to appropriate levels. There are several benefits to this plan.
First, less ash available to the borer means fewer trees to remove. The urban forest in Cedar Rapids is estimated to be comprised of 20-30% ash. The forestry department does not have the staff to keep up with the number of removals that the borer will generate. The situation will become dangerous as the trees die and fall apart, threatening people and property. By removing some of the trees in poor condition, with structural issues or on streets with high ash populations, we can reduce the number of future removals. It also allows us to increase our diversity as we replant. Every tree removed is replaced with at least one new tree. There are 20 to 30 different species used for reforestation yearly. Minimizing future aesthetic damage is another benefit. If we selectively remove and replace ash in areas with high ash populations, the new trees will have a chance to grow and increase in size, hopefully minimizing the negative effects of the mass removals that come with an EAB infestation. Finally, by reducing the number of ash on our parkways to 10-15% of the overall tree population, Cedar Rapids will have a healthier urban forest in the future.
Currently, the city removes and replaces 100-200 ash per year. Homeowners do have the option of keeping the ash in front of their home, provided it is being removed due to population thinning and not for health or structural reasons. Please contact the City Arborist to make this request: 319-286-5616.
The current plan and timeline for the ash removal program is:
- City Arborist inspects high concentration areas of ash trees and generates a winter removal list: June/July.
- Progress Report item on topic prior to notifications: Mid July
- 1st series of notification letters to affected properties: Late July/Early August.
- City newsletter article. Submitted by Mid/Late July.
- Arborist handles the calls as received over the next several months.
- Prior to removals, 2nd set of letters: Min. 2weeks prior to removal.
- Prior to removals, a press release with information will go out along with a progress report update and news letter input: November/December.
- Removals in Dec to March.
- Removal locations will be added to the tree planting plan: Spring/Fall replant.
- Stump removals as crews are available.
- Start the sequence over again: June/July.
Treatment options for Private property ash trees:
Due to the large number of ash trees on the parkways, their condition and budget constraints, the city is not utilizing chemical treatments to treat trees for EAB. However, if you wish to treat the parkway ash in front of your home or a private ash on your property, the treatments are effective. Emamectin Benzoate, sold under the trade name Tree-Age, is the most promising option; however, Merit (Imidacloprid) is also a tried and proven treatment for this insect. There are several things to keep in mind when treating ash with these products:
1. First, an ISA Certified Arborist should evaluate private trees to see if they are in good condition. They should be a certified applicator through the state.
2. If the tree is a viable candidate, you need to realize that once you start treatment, you will be doing it for the life of the tree. If you stop, the insect can infest the tree and kill it.
3. These products are not preventative. The insect needs to lay eggs on the tree and those larvae need to hatch and chew through the bark to the vascular tissue in order to ingest the insecticide. In addition, some treatments require injections which create wounds (albeit small wounds) in the tree. So there will still be some damage and stress to the tree.
4. You do not need to start treatment until the insect is confirmed to be within 15-20 miles from your location.
5. You must realize that treatment does not guarantee survival. Current success rates are 90-95%. There is a possibility that you could invest the time and funds to treat your tree and it could still be infested and fail. You need to accept this potential outcome if you decide to treat.
6. If you treat a parkway tree, you need to contact Forestry so the tree can be evaluated, approved and put on a list so it is not removed prematurely.
Treatment is only part of an overall management program. The tree should be properly pruned on a regular basis (every 5 years or so), watered regularly and fertilized yearly. This will keep the tree in the healthiest state possible and allow it to be more effective in fighting off an infestation. This applies to all trees, not just Ash.