Don’t kiss your mistletoe-infected trees goodbye

by | Dec 17, 2014

Mistletoe-infected oak branch.  Image: J. O'Brien, USDA-FS,

Mistletoe-infected oak branch. Image: J. O’Brien, USDA-FS,

This festive time of the year usually has people in high spirits. And there are some folks who may be in even higher spirits … those who steal a smooch under the mistletoe!

Mistletoe is a sign of love and friendship in Norse mythology, and the holiday tradition of kissing under the mistletoe is rooted in England. But there is a dark side to this romance-inspiring plant. Not only is it toxic to humans, it’s also a parasite.

The plant is hemiparisitic, meaning it obtains some resources from its host. In the case of mistletoe, it obtains water and mineral nutrients from the tree it infests, but because it is photosynthetic, it is able to produce its own food. In other words, mistletoe does not rely on its host for 100 percent of what it needs to survive.

But can mistletoe harm a tree? The short answer is not much. Mistletoe can infect more than 110 species of trees, but is not considered a serious pest in North Carolina. When combined with other stress agents, it could result in a general decline in tree health or localized branch mortality. If a mistletoe-infected tree dies, then it was likely affected by other, more serious pests.

So, mistletoe isn’t exactly the kiss of death for a tree, but its presence can be unsightly or contribute to poor tree health. Usually, management is not recommended because not only is it a minor pest, but effective control is very difficult to achieve. The best recommendation is to enjoy it and maybe get a smooch or two from your sweetie during the holidays!