Mistletoe — more than a decoration
Published: Saturday, December 7, 2013 at 6:01 a.m.
Last Modified: Thursday, December 5, 2013 at 10:53 a.m.
Hanging mistletoe is a holiday tradition during the Christmas season in many U.S. homes, and its distinctive green leaves, stems and white berries are easy to recognize. This plant has a long history. In ancient times, Celtic Druids believed mistletoe was a holy plant because it rooted closer to heaven than any other plant. Its evergreen leaves, which are quite noticeable high in trees when other leaves are absent during dormancy, seemed to the Celts to symbolize the promise of spring's return. As history unfolded, these traditions were adopted by the English and French. Hanging mistletoe is a Christmas tradition in the U.S., while it is more commonly associated with New Year's Eve in Europe.
If you use mistletoe to add to your holiday celebration, handle with care, for the plant does have poisonous properties and is harmful if ingested. Keep the plants and decorations out of the reach of children and pets. After handling mistletoe, wash your hands thoroughly with hot, soapy water.
Soon after the holidays, mistletoe will be observed in trees throughout Central Florida. In February, when deciduous trees have lost their leaves, the round shape of mistletoe is readily observed, particularly against the backdrop of a gray winter sky. Trees in the red oak family — laurel, shumard, red and water oaks — will be most notable due to their prevalence in the landscape, but elms, hackberries, sycamores and wild cherry trees also are known hosts.
Because mistletoe is a parasite, its presence can weaken — and eventually destroy — the trees it infests, especially if the tree has been compromised by pests, drought, storms or old age. To sustain itself, the plant roots into the branch of the host and removes water and nutrients from the tree. This results in less food arriving further out on the branch, which means stunted growth over time and less leaves, leading to decline. If one has trees on their property and mistletoe is observed, two questions should be considered: Should anything be done about it? And if yes, what can be done?
To address the first question, consider the amount of mistletoe observed. Are there one or two clutches, or many? Consider the age and general health of the tree. Is it young with many years ahead, or is it already in decline? What is the value of the tree to the property? Does it make financial sense to invest in controlling this parasite, and are you willing to continue to invest in future years, if needed?
The second question is, what can be done? There are two primary methods for removal of this pest, neither of which is simple. The first option is pruning the mistletoe out of the tree. Simply removing the visible growth isn't enough. The plant's roots must be removed by pruning the infested branch at least 6 inches below the spot where the mistletoe is attached. These plants often are high in the tree, on small branches, and are difficult to access. This is not a job for someone who is not a professional climber. Moreover, the random growth of the mistletoe will probably require removal of branches that should be kept for proper form and structure. The resulting structural problems may be worse than the cure.
There is a second option: the application of a specialized growth-regulating chemical — Ethephon — to the mistletoe when the host tree is dormant, usually from December until early February. This means getting a pest control operator, with the proper license category and the right equipment, to make the application. Timing is critical; use of the chemical later in the year, when the tree is actively growing, can damage the tree.
Mistletoe presents an interesting dichotomy. Enjoy it during the holiday season, but handle with care. If you observe it in trees on your property, understand what its presence means for the health of the tree, and consider carefully whether a control is warranted.
David Holmes is Marion County extension director. Contact him at firstname.lastname@example.org.
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