Early this month, a mature and seemingly healthy ash tree was cut down in Franklin.
The tree was not damaged in a storm and was not threatening to fall on a house. The shade it threw was as efficient at cooling the home as a large air conditioner, and the large tree fit in nicely with the homeowner’s landscape plan.
Now there is a hole in that plan.
The cause of the tree’s premature demise was the emerald ash borer, a tiny insect that lays eggs in mature ash trees, leaving the young to feast on the tree, eventually killing it.
The emerald ash borer is an Asian pest that came to America in wood pallets aboard a freighter that docked in Detroit in 2002. Released into an environment that had no natural predator to eat it, the insect has slowly and unceasingly marched outward since then.
Watching the Indiana infestation map over several years, that spread is depressingly clear, as infestation reports spread from the northeast to Indianapolis and then Terre Haute and New Albany. Now all but a dozen counties in far southwestern Indiana are under quarantine.
A quarantine means wood should not be moved from one county to another. However, since the ash borer is present in Johnson County, wood should not even be moved from one part of the county to another to avoid infecting other ash trees.
To help prevent spread of the borer, people should not transport firewood. Even though a log might look OK, it can harbor a dangerous hitchhiker. Then when it arrives in new territory, nearby ash trees are placed at risk. So campers need to use only local firewood and not move logs from place to place.
The best way to identify the presence of the borer is to look for characteristic entry holes in the tree trunk. The holes look like a capital D on its side. If you think a tree has been infected, contact the Indiana Division of Forestry or the Purdue Extension Service in Johnson County for a positive identification.
Infected ash trees, particularly young ones, can be treated for the infestation. But this should be done by a qualified arborist, who first can determine if saving the tree is even possible.
By planting other species of trees, though, homeowners can at least ameliorate the loss from the emerald ash borer. Foresters and garden stores can recommend varieties that will achieve the same results as the ash trees.
Planting the trees now will mean mature trees in a decade or so. Then, if the ash trees die, there will be adequate replacements.
The devastation is almost inevitable. In time, ash trees in Indiana will end up like elm trees that were killed by Dutch elm disease.
Trees serve a special environmental role in all settings, urban, suburban and rural. They take large amounts of carbon dioxide out of the air and provide efficient cooling for a house.
Check your ash trees for emerald ash borer, and if the pest is present, take appropriate action. In the meantime, look to the future and plant replacement trees to take the ash trees’ place for the next generation.