Thursday, December 24, 2020

Mistletoe – Everyone’s Favorite Holiday Parasite by Vicky Spelman

Photo Courtesy Pexels

The Christmas Holidays have a rich association with plants and a couple of favorites are the Christmas tree and mistletoe.  In winter when many trees and plants are bare, mistletoe stays green.  

Kissing under a sprig of mistletoe hung from a ceiling or doorway is one of the romantic Christmas traditions.  A common meaning is that mistletoe is seen as a symbol of fertility and life, and this this could be why we kiss underneath it.   

There are hundreds of species of mistletoe, a parasitic green plant that grows on trees and shrubs, that are found around the world.  Mistletoes produce root-like structures that grow in the living tissue just under the bark (phloem) and in the wood (xylem), where they extract both nutrients and water from their host plants. 


Photo Courtesy Pixabay

In Colorado, they can infect our Conifers.  

CSU Photo: Witches’ brooms – dense, multiple branches on
lodgepole  pine infected with dwarf mistletoe

CSU Photo: Lodgepole pine infected with dwarf mistletoe
display witches’ brooms and dead branches.


1. Mistletoes are parasitic flowering plants that can infect and damage many tree species.

2. Dwarf mistletoes (Arceuthobium spp.) are leafless parasitic plants that infect several coniferous or evergreen tree species in many western states.

3. Ponderosa, lodgepole, limber, and pinyon pines and Douglas-fir are the most common trees affected by dwarf mistletoes in Colorado.

4. Juniper mistletoe (Phoradendron juniperinum) is another type of mistletoe that can infect several juniper species in many western states.

Management options include:

1. Pruning and removing trees to reduce or eliminate dwarf infestations

2. Plant resistant trees under infected trees, so when the infected tree is removed, there is a replacement

Source:  CSU - Mistletoe