- Author: Amy Breschini
Mistletoe
By Dale Norrington
Q What value does mistletoe have in the garden? Should we remove it, and if so, how? Zena Thomas - Atascadero
A A kiss beneath the mistletoe is an ancient tradition, linked by lore and legend to the time of the winter solstice. While mistletoe continues to play its part in our wintertime tradition, it plays a role in the garden as well.
A broadleaf, evergreen plant which produces its own nutrients through photosynthesis, mistletoe is also a parasite which utilizes its host for support, water, and additional nutrients. Mistletoe reproduces by flowering and producing smallish, sticky white berries, and seed. It is spread when its fruit and seed drop, stick to, and germinate on lower branches, or are eaten and dispersed to neighboring trees by animals and birds. Cedar waxwings, robins, juncos, and thrushes are among many birds which feast on the fruits of mistletoe. Mistletoe causes the formation of witches brooms, densely irregular clumps of branches, which are used by birds and small mammals for nesting and cover.
Several species of mistletoe occur among landscape trees. Phoradendron macrophyllum grows in ash, alder, birch, box elder, cottonwood, locust, silver maple, walnut, and zelkova. P. Villosum grows only on oaks, and Arceuthobium spp., a dwarf mistletoe, is found on conifers. Healthy trees can generally tolerate some mistletoe. Heavier infestations, though, can lead to stunting or death of host trees.
The most effective method of control is removal of branches upon which mistletoe grows. Thinning cuts are recommended, made at least one foot below the point of attachment of the mistletoe.
Pruning off the mistletoe itself will slow its growth and ability to spread to other trees. While it will often resprout, it will not flower and produce seed for several years.
Mistletoe can be thoroughly wetted with ethephon, a growth regulator, while its host tree is dormant. This will cause some clumps to fall, though they will often resprout. As with any chemical, label directions should be followed carefully.
Resistant species such as Chinese pistache, persimmon, Bradford flowering pear, crape myrtle, ginkgo, liquidamber, and sycamore may be used in or near heavily infested areas.
From our gardens to yours, we wish for you all of a garden's delight, and an enjoyable wintertime holiday season.
Got a Question?
Contact the University of California Cooperative Extension Master Gardeners: at 781-5939 from 1 to 5 p.m. on Monday and Thursday; at 473-7190 from 10 a.m. to noon in Arroyo Grande; and at 434-4105 from 9 a.m. to noon on Wednesday in Templeton. Visit the UCCE Master Gardeners Web site at groups.ucanr.org/slomg/ or e-mail mgsanluisobispo@ucdavis.edu.