EAB AND ASH RUST NOTES

 

6/3/2009

In light of recent news coverage about Emerald Ash Borer (EAB) and a recent outbreak of ash rust we want to clarify the difference since both affect ash trees. EAB is an exotic beetle that was imported to the U.S. from China by accident in 2002. EAB has been responsible for the destruction of millions of ash trees in twelve states with the largest concentration found in Ohio and Michigan. EAB only attacks the Genus Fraxinus (White Ash, Green Ash, Autumn Purple Ash are among the most commonly planted ash trees in this genus) and will not attack Genus Sorbus (Mountain Ash). EAB is not in Nebraska and we do not know when or if it will arrive to our state. The most current information about EAB is located on the USDA Forest Service web site www.emeraldashborer.info.

A flood of ash leaf samples showing signs of rust have been arriving at our store recently. Ash rust, is a fungus (Puccinia sparaganioides) that appears on the leaves and green twigs as small, round, orange bumps giving the tree the appearance that it has caught measles. Ash rust does not harm the tree and is not related to EAB. Once symptoms of rust appear on the tree, treatment is not a viable option. To prevent this fungus a fungicide needs to be applied just as the leaves come out in the spring, but again, the disease is rarely destructive enough to warrant special control measures. It is difficult to predict if ash rust will be a problem next year. The University of Nebraska-Lincoln Extension has ssposted a fact sheet outlining the disease in more detail: http://extensionhorticulture.unl.edu/Current/AshRust.shtml

If you have any questions or concerns about your ash, or any other trees in your landscape please know that you can visit our store to for more information. In order for us to better diagnose your tree’s aliment please provide us with a fresh sample; a branch that is 6”-8” long with both the good and bad symptoms showing. Digital pictures are always welcomed; however, we are not always able to see the finer details that could lead to solving the problem.

Scott Evans
Garden Shop Mgr.
Mulhall's Nursery
Phone: 402.496.0700
Fax: 402.547.5003

What's Bugging You written by Scott Evans, Mulhall's garden shop manger, is a bi-weekly post that provides solutions to local lawn and garden issues. The column will run as long as you have problems that you need help with.

We encourage you to tell us what's bugging you in your garden or lawn. Please submit your issues along with a picture of your problem and your contact information to whatsbuggingyou@mulhalls.com.

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