Bark nodules

Bark nodules are found on trees with a smooth trunk, for example: beech, ash, elm.

Recognize bark nodules
Bark nodules on the trunk of an ash tree, photo: Sjoerd van der Schuit

Bark nodules These are found on trees with a smooth trunk, for example: beech, ash, elm. The nodules consist of encapsulated (dead) cell material, not from the bark but from deeper within the tree.
Trees in urban areas in particular exhibit bark nodules. Trees in urban areas are more exposed to electromagnetic fields than in the wild, so an association with electromagnetic fields was suspected. However, a study by Wageningen University (November 2013) found no evidence.
The trees are not suffering health damage from the nodules.

Where to find

  • General on trees with a smooth trunk (beech, ash, elm, hornbeam)

Remedy

The tree does not experience any damage from the nodules, therefore control is not necessary.

Prevention

Does not apply.