Will Mistletoe Kill My Trees?

Mistletoe is easiest to see in the winter months when deciduous trees are dormant and drop their leaves.

Published January 28, 2010, By KEVIN BASSETT

Normally, the simple answer to this question is no. In and of itself, infection of a tree by mistletoe does not kill the host tree. However, mistletoe is a parasitic plant that steals water and minerals from a tree and derives its nutrition at the expense of the tree. When combined with other significant stresses, such as drought or construction injury, death can occur and mistletoe will have played a part in the tree’s demise.

The winter months are the most efficient months to remove mistletoe from deciduous trees, since with leaf drop, infection sites—particularly new locations are easiest to see. In heavily infested trees, complete eradication of mistletoe is next to impossible; however, control can be achieved with judicious pruning. The level of infestation can be managed to the benefit of the tree. The sooner the small young mistletoe plants are pruned away, the less chance further infection sites will develop. When you see the small white berries (seeds) on the mistletoe plant, you are about to see a dramatic increase in the number of infection sites throughout the tree. More infection sites will mean more of the tree’s water is being stolen, resulting in a greater loss of vigor. This opens the door for another stress agent to do even greater damage and accelerate the decline of tree health.