Mistletoe
By Dale Norrington, Master
Gardener
A kiss beneath the mistletoe is a
Christmas tradition the origins of which may predate Christianity. Lore and legend tell of white-robed Druid priests
climbing sacred oaks to cut mistletoe for fertility rituals at winter solstice,
centuries before the birth of Christ.
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 the 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 re-sprout, 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 re-sprout. As with any chemical, label directions should
be followed carefully.
Resistant species such as Chinese pistache, persimmon,
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 the 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. Pruning
off the mistletoe itself will slow its growth and ability to spread to other
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. While it will
often re-sprout, 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 re-sprout. As with any chemical, label directions should
be followed carefully.
So enjoy the role which mistletoe plays during the
holiday season and in the garden ecosystem, control it if need be, and on
behalf of the UC Master Gardener Program Garden Notes writers – "Happy
Holidays."