Don’t get caught under too much mistletoe this season! I’m not referring to the bunch hung from the ceiling for sweethearts to kiss under at Christmas; by all means, carry on if you are so inclined. What I am concerned about is the mistletoe still hanging in the tree.

I understand that a lot of the plants we traditionally associate with Christmas are evergreen, and used because, well, they are green when everything else is bare for the winter, but I never understood the romantic association with mistletoe. Its history as a symbol of fertility and love goes back thousands of years, well beyond today’s interpretation as Christmas décor, but when you get down to it, mistletoe is a parasite. As a symbol of love, choosing a parasite seems a bit of a cynical choice.

Our native mistletoe, often called American or Oak mistletoe, can kill the trees they are growing on. They do use their green leaves to photosynthesize, but they take water and other nutrients from the tree. If too many bunches of mistletoe invade, they will slowly suck the life out of the tree.

In summer these green clumps blend in with leaves and are not very noticeable. Now, with the branches bare, they are easy to spot. Check the trees around your house. If you see multiple green clusters at the top, I’d keep a close watch on those trees; they may begin to lose branches and eventually need to be removed from the landscape.

As seen in these two photos, mistletoe can be difficult to spot in summer (left) but stands out after its host drops leaves in the fall (right)
Photos from: Randy Cyr, Greentree, Bugwood.org

Technically you can treat mistletoe by pruning it out two feet below where it is attached to the tree, or by pruning it off and wrapping the cut with black plastic for a couple of years to prevent it from growing back. The problem with this is getting to the mistletoe. It is usually too high in trees for either of those methods to be practical. You would need someone with specialized skills and equipment, and I’ve never seen an arborist offer that service. For most of us, the best plan is to be aware and keep a watchful eye out.

As you hang up your Christmas mistletoe this year, take a moment to monitor your trees. Make sure you leave any pleasant associations with mistletoe for Christmas kisses with your sweetie and recognize it for the water-stealing parasite that it is when it comes to your trees.