For centuries, many cultures linked mistletoe, a member of the sandalwood family Santalaceae, to life-giving power, fertility and peace. The Romans celebrated with mistletoe at the festival of Saturnalia. In 18th century England, a “kissing ball” of mistletoe evoked romance and goodwill.
Yet mistletoe is anything but simply an innocent decorative holiday sprig of leaves and berries. I liken it to an interloper tethered to a tree. Rick Gibson, director of University of Arizona Cooperative Extension describes it as “almost like a cancerous type of growth” that deprives its host of food and water resulting in disfigurement and eventually death. Gibson says that mistletoe thrives even in the dry climate of the desert, in mesquite, juniper and pine trees.
Mistletoe tethered to a tall tree. photo credit Launa Herrmann
The dwarf mistletoes, Areuthobium, and the broadleaf, Phoradendron, are parasites that thrive in California sucking the life out of plants, shrubs and trees. Some of our wildlife is attracted to broadleaf mistletoe for food and shelter. Birds especially are drawn to mistletoe for its tasty berries and nesting sites — and that's where the problem starts.
According to UC IPM Pest Notes, Publication 7437 the sticky berries produced from October to December attract birds such as robins and cedar waxwings. The berry seeds attach to the birds' beaks and feet, then are carried to the next branch, the next tree and the next shrub. Mistletoe is also spread by bird droppings. After a seed germinates, the mistletoe penetrates the bark and grow “into water-conducting tissues, where rootlike structures called haustoria develop.” (For more information, check out the following link http://ipm.ucanr.edu/PMG/PESTNOTES/pn7437.html?src=blog38976
Broadleaf mistletoe (Phoradendron macrophyllum) is an evergreen parasitic plant that grows on a number of landscape tree species in California.Hosts of broadleaf mistletoe include alder, Aristocrat flowering pear, ash, birch, box elder, cottonwood, locust, silver maple, walnut, and zelkova.
ipm.ucanr.edu
During my research I learned that mistletoe berries also have the capacity to explode, meaning the sticky seeds released into the air can travel an average speed of 60 miles per hour and land as far as 65 feet away. Adding that detail into the mix of this problem parasite, I begin to understand why eliminating or managing a mistletoe infestation is not a simple task.
Although pruning is a recommended step to control growth, the UC Pest Note indicates that even if “visible portions of mistletoe are removed,” re-sprouting can occur from the haustoria since the root-like structures grow unseen within the branches. In time, trees and shrubs severely infested, which are also stressed by drought or disease, are best removed.
