By Donna Hagar, Somervell County Master Gardener
It must have been the mistletoe
The lazy fire, the falling snow …
… It only took one kiss to know
It must have been the mistletoe!
Ah, tis the season for the quintessential mistletoe. Mistletoe is an important part of the holiday season. Many girls and boys stole their first kiss by standing under mistletoe branches.
Unfortunately, mistletoe has some qualities that Christmas love-birds probably prefer to ignore. Mistletoe, or Phoradendron tomentosum is a parasitic plant, growing on limbs of trees, with elms and hackberries favored among our native trees. Mistletoe can grow 2-5 feet in diameter, and with its evergreen foliage, becomes highly prominent in our landscape trees in the winter, when their host trees have lost their leaves.
As a parasitic plant, mistletoe grows into the wood of the host tree sucking water and minerals. Even though mistletoe is a true plant, meaning it can make its own nutrients from photosynthesis, it is the use of the tree’s water resources that can cause the biggest problems.
While mistletoe rarely kills entire trees, limbs are certainly weakened by the loss of water, and with the added drought endured the last few years, mistletoe is just one more added stressor that trees must overcome, and thus may make the tree susceptible to other problems.
While mistletoe is present 12 months of the year, the high visibility during the winter months springs homeowners into action to control the plant. Small infestations can be controlled simply by removing infected limbs at least 12 inches below the mistletoe. Because the roots of mistletoe are embedded into the tree tissue, cutting just the plant, leaves roots behind that will just sprout more mistletoe.
Again, because the root system is so closely tied to the vascular system of the trees, chemical controls are not affective without also adversely affecting the tree.
Mistletoe produces white berries, which are eaten and spread by birds. It takes 2-3 years before a mistletoe plant matures to produce the berries, so control early is the most promising means of keeping it in check.
Are there benefits (other than the obvious ‘first kiss’) to this prolific plant? As mentioned above, birds do feast on the berries, which are high in fat and full of protein. Other mammals, deer, squirrels and porcupines also partake in the berries. Several bird varieties nest in the foliage of mistletoe. Mistletoe is host to 3 varieties of hairstreak butterflies. Research is also being done on the extracts of mistletoe in the treatment of certain cancers.
So, friend or foe? Although a parasite that can weaken affected trees, trees can survive well with small infestations. So removal is recommended if it can be done safely and economically.
Resources: aggie-horticulture.tamu.edu; National Wildlife Federation Dec/Jan 2014