I’m curious as to what is growing at the base of my tree and whether or not I should do anything about it. There are a number of nodules just below the grass line and are attached to the tree base about 1-2″ below the dirt. photos attached.
This appears to be a fungus known as dead man’s fingers (Xylaria polymorpha), which usually appears in clusters of 3 to 6 “fingers” at the bases of trees or shrubs. It has been described as looking like black knuckles with arthritis. The fungus prefers apple, maple, beech, locust and elm trees, but can also invade several other species of trees and shrubs. It is a saprophyte, meaning that it invades wood that is dead or dying.
From your photo and your description, the fungus appears to be growing on the tree roots or at the base of the trunk. If this is the case, it is bad news – as this indicates that the tree is not healthy. The fungus will gradually break down the tree structure, and cause soft rot, for which there is no cure. Note that, in some cases, the fungus may grow from wood mulch (not on the tree) and in such cases may not be a sign of disease — simply removing the mulch would eliminate the problem. Unfortunately, I don’t believe this reflects your situation.
You may want to consult an arborist, as there appear to be several similar trees planted on the property near the infected tree and it is important to identify those that are also diseased. It is recommended that infected trees be removed, as they can collapse without any warning. Don’t use the wood from the tree as mulch. And avoid planting trees or shrubs that are susceptible to dead man’s fingers in spots where you have seen the fungus appear, as root fragments can persist for up to 15 years after an infected tree is removed.
Finally, it is important to make sure that your remaining trees remain healthy and stress-free, e.g., by keeping them well-watered and fertilized.
Here are some links with additional information:
- First Nature. Xylaria polymorpha (Pers.) Grev. – Dead Man’s Fingers
- University of Wisconson Extension. Dead man’s fingers
Landscape Ontario provides the names and contact information of tree care professionals and arborists.
All the best with your lovely trees, and I am sorry to have been the bearer of bad news!