Emerald ash borer arrived in the Madison, Wisconsin area Spring 2014, and we pruned more ash trees last year than the last three years combined! More people are looking to treat and save their ash trees because many ash are just starting to reach maturity and cast wonderful shade. There are few sure bets in tree care, but we do know with certainty that if you don't treat your ash tree, Emerald Ash Borer will kill it. The tough part, however, is not all trees are good candidates for treatment. The below information should help you begin asking good questions about your tree and maybe finding some answers. If you still have questions, please contact us and we can help answer them.

Is Your Ash Tree Worth Defending from Emerald Ash Borer?

We believe protecting ALL Ash trees from Emerald Ash Borer, as a rule, is not the most responsible or logical approach.  There are several questions you should ask yourself before considering EAB treatments:

  • Are you willing to treat your tree long-term (more than 10 years)?  Cost varies on the size/diameter of your tree's trunk. 
  • Is your tree structurally sound?
  • Does the tree have historical value?
  • Does the tree provide cooling value (shade) for your home?

About Chemical Emerald Ash Borer Treatments

Over the past decade Emerald Ash Borer treatments have become more effective.  If your tree still has approximately 60% of its canopy alive then treatment can be very effective and should be seriously considered. Once canopy dieback has passed the 30-40% range, however, treatment success is unlikely because the tree's ability to move water (and thus other resources) through its system is seriously compromised. At this point, removal may be your best option.

Treatments are based on the diameter of the trunk and are injected into the trunk every two years. The most common treatment is Tree Age, an insecticide  injected into the trunk through a pre-drilled hole.  Does this hurt the tree?  I'm guessing yes, but so does the flu shot I get every year.  It does not permanently damage the tree, however; the hole is plugged and the tree grows around the plug, leaving very little trace of the injection.  The insecticide is systemic and will kill Emerald Ash borers feeding on the tree. It also prevents new infestations because the tree is still toxic to EAB for some time.  The chemical does not harm birds or other animals, however.  

 Current research is starting to show that once the bug population peaks and begins to crash, treatments will be able to be spread out beyond the two year cycle. This is a welcome piece of positive information in sea of gloom and doom, the cost savings over time should be one more important factor considered in weighing the decision to treat or remove. Look at our bullet point list for some more factors to consider when making your decision. Or even better, have us come out and help you decide!    

Structural Assessment

Have your tree structurally assessed and then get a treatment quote from a certified arborist. Lately we have seen structurally compromised ash trees being treated by companies outside of the tree care industry. We have removed ash trees that split in half after being  treated for Emerald Ash Borer only months earlier.  Lawn care companies that do fertilizers and chemicals applications are also doing EAB treatments but their staff often do not  know what to look for in terms of tree context.  A certified arborist will be able to tell you if your tree is in good enough condition to treat it, there is no point in spending money on a tree that will need to be removed in five years.

The Pruning Factor

The last piece of this puzzle is pruning. Pruning is not related to EAB, but it is a factor in your long-term tree cost. Ash trees have a tendency to grow large, long branches, which leads to pruning/maintenance costs over time.  Our approach is to quote a pruning price (as needed) in conjunction with the treatment cost so you know up front how much it will cost to effectively save the tree in its current state. There is no point in treating your tree without having it assessed structurally because if it needs pruning or removal no treatment will be able to change that fact. If we recommend treating a tree and there are branches in need of pruning (or other help), we will always make that part of the conversation.

Useful links to answer questions related to Emerald Ash Borer