Fungus and other blights can wreak havoc on trees, and the threats facing our trees and forests vary from year to year. Here are some of the top threats facing trees in Front Royal, Warren County, and the greater Shenandoah Valley.

Thousand Cankers

This disease is relatively new to Virginia, having only made its way to the east coast in the last ten years. Thousand Cankers Disease (TCD) hits trees with a one-two punch of the walnut twig beetle and fungus. It primarily affects black walnut trees but has had impacts other tree species as well. The beetles tunneling into the trees which then become infected with a fungus that causes black cankers to grow and spread. The cankers aren’t visible from the outside until the disease has progressed pretty far, at which point the black cankers become apparent and the tree starts to die.

ThousandCankers.com has a wealth of information on the topic including what areas are affected by the disease. Several counties in Virginia have requirements to quarantine trees and other materials related to the spread of Thousand Cankers Disease. While we are now all too familiar with quarantining people, thanks to Covid-19, you might wonder how to quarantine a tree, since they’re not likely to wander around. But humans have been unintentionally spreading the disease to new areas by transporting the infection through mulch, firewood, and even planting trees that have an undiscovered case of the infection.

The quarantine restricts the movement of all walnut material including nursery stock, budwood, scionwood, green lumber, and firewood. While Warren County is not currently on the list of quarantined counties, we wanted to include this disease to alert the public. Nearby counties are quarantined, and it could be a matter of time before the disease makes its way here, so we want everyone to know what to look out for.

One important way you can help prevent the spread of Thousand Cankers Disease is to buy or collect only locally cut firewood. If you have already brought firewood from another area, burn it soon. Do not leave it sitting around, and do not take it with you anywhere. Encourage your friends and neighbors not to move firewood distances greater than 50 miles. You can also read up on the relevant Virginia statute concerning the disease.

Bot Canker in Oak Trees

Oak trees in our region are also threatened by a new pathogen called Bot Canker. It is caused by an infection of the fungus Diplodia corticola and was first observed in this area in the fall of 2016 in West Virginia. The fungus restricts the ability of oak trees to take in nutrients and water, eventually starving them. Fortunately, it has only affected a small number of oaks so far, but it has the potential to be spread widely, especially to trees weak from other environmental stressors.  

Image: @kasson_wvu

Anthracnose Fungus in Dogwoods

As the state tree, Dogwoods have a special place in the heart of many Virginians and can be seen in urban yards and rural settings. Fortunately, this particular fungus usually only causes a mild condition and the vast majority of healthy trees survive after battling it for a year or two.  Some symptoms to stay on the lookout for are tan spots and losing leaves prematurely, cankers on twigs, and flowers with spots on them.

Dogwood anthracnose (Discula destructiva) leaf blotch. Image: Mary Ann Hansen

Acting as quickly as possible will help you to preserve your trees and can even save the rest of your yard from the same blight. If you have seen any of the symptoms we’ve mentioned on your trees or those of your neighbors, or have any suspicions that there is something wrong with your trees, give JC Tree Care a call at 540-636-4182 or contact us online. We can work to prevent the spread of diseases, treat diseased trees, and safely remove trees that are diseased. Our goal is always to save your trees, but that isn’t always possible. In cases where a tree has to be removed, we can talk about planting new trees as well.