For centuries, sweethearts have stolen kisses under the green
branches and white
berries of holiday mistletoe. Few of them know the plant is
actually a type of parasite
that draws part of its lifeblood from its tree host.

R. Jarret, UGA CAES

MISTLETOE, though good for kissing, can harm the tree it lives in and on. Though not a true parasite, mistletoe steals water and nutrients from the tree it grows in.

“Mistletoe is actually an epiphyte,” said Jerry
Walker, a plant pathologist with
the University of Georgia
College of Agricultural and
Environmental Sciences.
“It’s not a true parasite, because it produces its own
chlorophyl. It draws water and
other nutrients from the host tree.”

Walker said mistletoe’s leathery green leaves contain
chlorophyll that lets it make
sugar carbon dioxide and water, like all other green
plants.

“Its root system invades the internal tissues of the host
tree, extracting water
and minerals, and anchors it to the host,” Walker
said. “Basically, it grows on
another plant at its expense.”

Sharing its water and minerals with mistletoe is no
problem for healthy trees. But
unhealthy trees can sometimes fall to the added
stress. “Weak, older and unhealthy
trees are often hosts for mistletoe,” he said.

The mistletoe found in the South is American
mistletoe. “In the western states,
they have dwarf mistletoe, which is very harmful to the host
plant, especially
conifers,” Walker said.

Mistletoe may have gotten its link to the holiday season
in part because it’s so
noticeable in the winter.

“You see it in trees this time of year because most of
its hosts are deciduous and
have lost their leaves,” said Walker. “It’s there year-
round. You just can see
it so easily now.”

You see mistletoe in trees around homes and cities more
often than in undisturbed
forests. UGA wildlife scientist Jeff
Jackson has his own theory as to why.

“Mistletoe provides birds, especially mockingbirds, one
of the few winter berries
around,” Jackson said. “Where you see mistletoe in trees,
you’ll most likely see
mockingbirds perched on the branches.”

Jackson says mockingbirds are very territorial. They tend
to make their homes in areas
where humans live.

“They don’t feed from your bird feeder. But they’re in
your yard driving other
birds away,” he said. “They also perch high in trees, and
that’s where mistletoe
tends to grow.”

The wind and several bird species spread mistletoe from
tree to tree. The birds feed on
the white berries, roost in the treetops and deposit the
seeds on the branches.

Birds aren’t the only ones that benefit from
mistletoe. “It’s the sole host plant
of an interesting butterfly called the great blue
hairstreak,” Jackson said.
“This butterfly is in the same family as the little blue
butterflies you see in the
spring.”

In caterpillar form, the butterfly feeds on
mistletoe. “Its wingspread is a little
over an inch, and the wings reflect a metallic blue when
open,” said Jackson.
“If you want to see it in your garden, watch under the trees
that host
mistletoe.”

Although birds and butterflies find the berries tasty,
they’re toxic to humans. When
decorating with mistletoe, keep it out of reach of children
and pets. The stem and leaves
are toxic, too, and can irritate skin.

In most cases, mistletoe doesn’t damage trees. However,
in rare cases of multiple
infections, it may. Infected branches, and even the whole
tree, may die.

R. Jarret, UGA CAES

MISTLETOE starts out as a tiny, harmless- looking plant on a tree, but can grow into a problem.

“It’s an interesting plant. But it’s not desirable,
unless you grow it for harvest
at Christmastime,” Walker said. “There are no chemicals
labeled in Georgia for
its removal. But you can control it by cutting it out of the
trees.”

Cut out infected limbs 1 to 2 feet below the infection
point. If you remove only the
mistletoe, it will probably regrow.

Removing infected limbs may not be easy when the
mistletoe is in the treetop.
“Years ago, people would shoot it out with shotguns,” Walker
said. “But I
don’t recommend that.”