Witch’s broom is a deformity on a tree branch due to infestation by a fungus.
Do not confuse with:
Mistletoe
Witch’s broom is a deformity on a tree branch due to infestation by a fungus. In birch, the fungus Taphrina betulina is the causative agent of Witch’s broom.
Witch’s brooms also occur on apple trees; these are caused by phytoplasms: bacteria that live on the mesophyll. Infection occurs through the use of infested scions and by cicadas carrying the bacteria.
In spruce (particulary Norway spruce), Chrysomyxa – a rust fungi – is the possible cause of witch’ sbrooms.
Where to find
- Birch
- Apple tree
- Spruce (Picae)
Control
Prune the branch with witch’s broom. To avoid contamination, it is best to burn the witch’s broom or put it in the garbage bin.
Prevention
Does not apply.
