Wait Till After the Cicadas to Plant Trees

 I’ve lost my favorite ash tree to the destruction of the Emerald Ash Borer that was first found in Prince William County in 2010. In the last decade it spread across the county and my property. Early on the woods covering the back 7 acres of my land had become infested with Emerald Ash Borer and I lost many trees. When the Emerald Ash Borer reached the large ash trees in my ornamental garden, I contacted an arborist to see what could be done.

Pesticides can be applied to individual trees to protect them against Emerald Ash Borer and reportedly can save an ornamental lawn tree. For the pesticides to work the trees must be healthy and have at least 30% of their leaf canopy remaining. There was more than that on my ash. The trees in my wood were beyond hope, but I still held hope for the big ash on the side of the house.

The pesticie protocol in areas were groundwater is used for drinking water is for either emamectin benzoate or a specific formulation of imidacloprid to be injected directly into the base of the tree trunk. The insecticide is transported within the vascular system of the tree from the roots and trunk to the branches and leaves- if it works. This reduces hazards to groundwater and to other plants from drift and protects the applicator from exposure. 

Imidacloprid is not particularly soluble in water. The pesticide profile presented in the Extension Toxicology Network Pesticide Information guide concluded there is generally not a high risk of groundwater contamination when products are used as directed and appropriate precautions are taken. Similarly, the Canadian Water Quality Guidelines for the Protection of Aquatic Life noted that when imidacloprid is used correctly, it does not characteristically leach into soil layers leaving the groundwater unimpacted. So, with hopes high and risks low engaged the arborist service to follow the protocol for treatment for the next few years. Unfortunately, despite the treatment, I watched over as the tree died.

This past summer the technician from the arborist came to the door to tell me what I already knew, the tree was effectively gone. I wanted to make arrangements (sounds like a funeral, huh?) to remove the tree before winter, but my husband was resistant. I was afraid of falling branches in winter storms, but my husband still held out some hope and did not want a hole in the yard, I had told him that I would not replant this year because of the cicadas.

 In Virginia there are eleven primary broods of the 17-year cicada and two primary broods of the 13-year cicada. Every year they will emerge somewhere in the state, but Brood X due in 2021 is one of the largest and impacts our area in Northern Virginia including Prince William, Loudoun, Fairfax, and Fauquier counties.

Both the 17-and 13-year cicadas damage many ornamental and hardwood trees. Oaks are commonly attacked but the most seriously damaged are newly planted fruit and ornamental trees. Pines and other conifers are not commonly attacked. This fall is not be a good time to plant any of these trees in our region as they may be damaged next spring when Brood X emerges. Since I intended to replace the tree with an oak, tulip or possibly another species, I am going to wait till next year after the cicidas have risen and gone to plant.

So, I delayed taking down the tree, but it is shedding branches in each storm. Finally, my husband agrees, it’s time.  I have already contacted Wetland Studies and Solutions (who are owned by Davy Tree) and when they come out next month to work on the woodland they will address removal of the ash tree. A sad moment.