Mistletoe - Friend or Foe?

Some things that I have heard during my life about mistletoe are: 1) stand under it if you are looking for a kiss, 2) it is poisonous and 3) it will kill your trees. You may have mistletoe in some of your trees, so it would be nice to know if it is friend or foe. The answer however is somewhat mixed and might be subjective based on your situation.

Various kissing traditions about standing under mistletoe have flourished for hundreds of years. I will leave it to the reader as to whether this informs the mistletoe as friend or foe discussion.

Yes, mistletoe is poisonous to some living creatures including humans, dogs and cats. Mistletoe varieties growing in America are purported to be less toxic than mistletoe found in Europe. In Europe extracts from mistletoe are showing signs of being less toxic than chemotherapy and effective against colon cancer. Some mammals consume mistletoe as part of their normal diet, especially during the

winter when other food sources may be scarce. These include squirrels, deer and cattle. Many birds such as robins, bluebirds and waxwings eat the berries. Other birds such as spotted owls, chickadees and nuthatches use the "witches broom" mass of branches to nest in. Mistletoe provides an early pollen and nectar source for bees and 3 species of hairstreak butterflies depend on this plant as food for their caterpillars. These are just some examples that can confuse a friend or foe discussion with regards to mistletoe.

Mistletoe is a parasite. It does draw its water and a portion of its nutrients from the host tree. The place on a branch where mistletoe attaches to will become noticeably thickened and if you wish to permanently remove a mistletoe clump, you can't just chop off the base of the cluster of mistletoe branches. You must also cut the limb about a foot towards the center of the tree from the thickened attachment point. But should you do this? The answer will vary depending on your situation. I read about a biologist whose work with mistletoe began with a focus to find a way to eradicate it. After decades of studying the plant he came to appreciate its part in the overall forest ecosystem and introduced some to a few trees in his own yard. Mistletoe can definitely weaken a host tree, especially if there is a heavy infestation and/or if extreme drought occurs. As part of an overall forest ecosystem, mistletoe infected trees will likely have shorter lifespans and according to several studies will contribute to a higher percentage of snags and nest cavities and therefore a larger population of cavity nesting birds in the forest.

So, mistletoe, friend or foe? You will have to decide for your own unique situation.