Mistletoe

By Jerry L. Goodspeed, USU Extension Horticulturist

The first time I saw mistletoe was on the University of California at Davis campus. It was mid-March, and it looked like the trees were starting to leaf out just on the tips of the branches. I was wrong. Mistletoe had taken up residence on the oaks and ash trees surrounding this beautiful campus.

Mistletoe is a parasitic plant. A parasitic plant is one that feeds and lives off another plant. There are not many parasitic plants, so it is a bit rare in some areas. I probably shouldn't dedicate a whole article to a little, almost worthless plant, but it is in demand and of interest during Christmas time.

Mistletoe is a relatively new Christmas tradition. There are many different legends associated with it. Like holly, the evergreen mistletoe is most noticeable during the winter months after other leaves have fallen. In past ages this gave it a since of sacred awe.

In Holland I remember hearing legends about the Druids of Old Europe needing a golden knife to cut the sacred mistletoe out of Oak trees. As it was cut, it would need to fall on a white sheet and be carried away by virgins. How much truth there is to this, I don't know, but it makes a good story.

The tradition of kissing under mistletoe probably stems from its reputation as an aphrodisiac and a fertility source. Many years ago in England it was a New Years tradition. Maybe we thought there was enough kissing going on during New Years so we moved it to an earlier holiday.

Leafy mistletoe can be very attractive with its red, pink, or white berries. As a parasite, mistletoe must have a host to survive. It attacks mostly deciduous trees, and is usually found in warmer climates.

Unlike some truly parasitic plants that depend completely on their host for survival, mistletoe can produce its own food. It gets its water and nutrients from the host plant. Mistletoe has a root-like structure (called a haustoria) that penetrates through young, thin bark into the water and nutrient carrying tissue of its host. This damages the host plant, but is usually not fatal.

Over a period of time, the haustoria grows several feet through the plant, then sends up new sprouts. This plant is usually propagated by seeds, which either fall or are carried by birds or small animals to new branches and twigs where they begin to grow. Since the seeds are sticky, they can be transported on a birds beak from one tree to another.

I have never seen leafy mistletoe growing in Northern Utah. It is too cold and dry for this particular parasite. We do, however, have a relative, the dwarf mistletoe, that invades conifers. It is generally found growing in our higher elevations.

Yes, mistletoe is part of our Christmas traditions here in America. But, I have to admit that as a horticulturist, I avoid it. Kissing under a parasitic plant just seems horticulturally wrong. Maybe a new tradition should be cutting the plant with a golden knife, and then giving the golden knife to your local horticulturist. Just a thought. Have a Merry Christmas with or without the mistletoe.


For more information, contact your local USU County Extension office.
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