Mistletoe is known around the world primarily as a plant sprig that people traditionally hang in their doorway during the holiday season in hopes of catching their loved ones under it to receive a kiss. But did you know that Mistletoe is actually a parasite that can cause considerable damage to your trees? It’s also highly toxic to humans and pets, so be sure to dispose of it properly.

Mistletoe uses trees such as oaks, elms, firs, pines, apples, and elms as well as other types of trees as a host by attaching itself to the tree’s bark. It does not feed directly on the tree but still can cause considerable damage if not removed. The damage is a result of the roots of the Mistletoe plugging the vascular system of the tree. The plugging of the vascular system causes bulging and distortion of the limbs on which the Mistletoe is attached and can potentially compromise the strength and vitality of the limbs if the Mistletoe is not removed.

Mistletoe is spread primarily by birds and is more likely to develop in stressed trees. Once a specific tree or area has developed Mistletoe, the spreading or growth of the parasite seems to accelerate. The heavier the infestation, the quicker it spreads.

The most effective control is a combination of measures — increasing the tree’s health and vigor and physically removing the Mistletoe. It is best to remove the limb of the tree where the Mistletoe grows rather than simply remove or knock off the green Mistletoe, for the roots of the Mistletoe will quickly put forth new growth. However, if the Mistletoe is attached to the trunk or large limb, removing the growth will retard future growth of the tree. The removal can easily be performed by experienced tree climbers. Mistletoe is easy to spot in the winter because its leaves stay green all year long. The most efficient time of the year for removal is during the dormant season when the trees are without leaves.

Mistletoe control is not a one-time occurrence, but rather a regular part of ongoing tree care for trees susceptible to Mistletoe. The frequency of the need for removal will be affected by several factors — weather conditions, amount of Mistletoe in the surrounding area, overall health of the trees, and quality of previous removal of Mistletoe.

There are a few products labeled for Mistletoe control; however, at this time, their effectiveness and the potential hazards and negative effects on the trees and other plant materials prevent recommending them for use. These materials are anti-fruiting agents and affect not only the Mistletoe but also the desirable plant materials they contact. Hopefully, at some point in the future there will be a spray product that is both effective and safe, but until then physical removal is the only recommended control.

If you have additional questions about Mistletoe or other tree care questions, please call Moore Tree, a member of the Lambert’s family of companies, at 214-352-6088.