American Mistletoe (Phoradendron serotinum)
Look up into the tops of deciduous trees in the dead of winter. See anything interesting? Nestled in the top of this elm tree is a bright green cluster of American mistletoe. It could almost be mistaken for a nest of some sort, but is more commonly referred to as a “witches’ broom.”
Mistletoe attaches its roots onto the “host” of a healthy tree, stealing valuable nutrients from the tree. (The Greek name for the American mistletoe tree, Phoradendron, translates as follows: phor meaning “thief,” and dedron meaning “tree.”)
How does mistletoe get into a tree in the first place? Since February is National Bird Feeding Month, this seems like an appropriate time to address that question. Birds are the main propagators of the mistletoe crop. They feast on the white sticky mistletoe berries from one tree, then fly off to the next tree, where the birds deposit any sticky berries they might be carrying onto the bark of that tree. The berries adhere to the bark and send out roots within days. Those roots work their way into the tree bark, enabling the establishment of another cluster of mistletoe.
Today mistletoe is considered an important ecological organism, despite the potential harm it may cause to host trees. The berries are consumed by a number of animals, and the “brooms” are favored by birds (owls and sea birds) for nesting and roosting. In other words, the greater the mistletoe density, the more diverse the wildlife population due to the benefits of food and shelter it provides in woodland and forest areas.
If the determination is made to remove the mistletoe, the entire limb of the tree must be removed and disposed of. The roots of a mistletoe broom may extend up to a foot along the host limb, so care must be taken in the removal of the branch, and consideration given to the long term health of the tree. Improper pruning will destroy a tree much faster than a mistletoe broom.