Garden Calendar: There’s more to mistletoe than kissing traditions

Mistletoe, a holiday staple, is actually a parasite that attaches to trees and saps the life out of the host by syphoning off nutrients and water.

While others are content to kiss under the mistletoe during the holidays, put it under their pillow to inspire dreams of Prince Charming, or use it as an herbal remedy, I have to wonder how a poisonous parasitic plant got such a good reputation.

There are about as many theories regarding why Americans kiss under the mistletoe as there are suggestions for its good uses. Because the plant lacks roots, I think it is fair to say many of the theories and suggestions do as well. I can tell you a few things about mistletoe with certainty, though.

Mistletoe is a parasite that grows in trees. Parasitic plants like mistletoe are completely or partially dependent upon their host for survival, unlike epiphytic plants that take their water and nutrients from the air or nonliving organic material. Moss, algae, lichens, and some orchids are a few examples of epiphytes.

Dwarf mistletoe is similar to mistletoe but lacks leaves.

Because of their parasitic nature, mistletoe and dwarf mistletoe can cause tree death. They literally suck the life out of the tree, in the form of water and nutrients. Although mistletoes and dwarf mistletoes are common across the United States and Canada, dwarf mistletoes that infect pine, spruce, fir and juniper in Colorado and western states are considered to be the most problematic.

Oak mistletoe is the only species documented in Kansas and is found in the southeast corner of the state.

The method by which mistletoes and dwarf mistletoes spread is even more interesting than the plants’ existence. Mistletoe seeds, hidden inside a tasty-only-to-birds berry, are eaten and later deposited by the birds on branch tops and other favorable locations. Use your imagination here.

Dwarf mistletoe seeds prefer to spread themselves rather than relying on animals. Their berry-like fruits actually explode, shooting seeds away from the plant at nearly 60 miles per hour. Dwarf mistletoe seeds are sticky so they can adhere to any surface.

Mistletoe leaves, stems and berries also contain toxins that are considered poisonous to humans, cats, dogs and horses if ingested. One of the kissing legends makes note of this by including a Greek god who is shot with a mistletoe arrow.

The United States Department of Agriculture says children and pets are at a higher risk for mistletoe poisoning than adults, and the most common symptoms are gastrointestinal disorders. In a 2009 press release, the American Association of Poison Control Centers says to treat mistletoe with respect rather than fear, though. They note that in both 2007 and 2008, only one person in the United States saw a “moderate medical outcome because of mistletoe exposure.”

Mistletoe does have a few good qualities. The berries are a food source to birds and other wildlife and may induce additional fruiting on their respective host plants. Mistletoe and dwarf mistletoe also often cause the trees they are growing on to distort and produce clusters of branches referred to as witches’ brooms, which create shelter for nesting and roosting.