Mistletoe: 'It's like a cancer'

Mistletoe: 'It's like a cancer'

Mistletoe — the stuff of holiday romances — could spell the kiss of death for some legacy oaks in Medford.

Great masses of the dark green parasite embrace oak trees in a neighborhood near you, sucking the life out of them.

Walt Locke, Medford Planning Commission member, said the city's heritage oaks are in danger from this pesky plant, whose roots embed themselves into the branches of trees. Locke brought his concerns before the planning commission recently.

Bill Harrington, the city's arborists, said Medford has aggressively removed the parasite over the past five years, though more needs to be done.

When he started with the city in 2005, Harrington said, "I was shocked at the amount of mistletoe we had in parks and along streets."

In a three-year period after he arrived, mistletoe was removed from 500 trees.

Harrington said he's got his hands full dealing with 9,000 trees under his care in Medford's public areas. Trees on private property are the owners' responsibility.

At Eastwood Cemetery in east Medford, Harrington pointed to Oregon white oaks where mistletoe had been removed, then other trees where it is still growing.

An oak growing on private property arched over into the city's cemetery, providing another source for the parasite to spread. The berries that grow on the mistletoe are eaten by birds then later excreted and deposited on other trees.

Mistletoe, which is found throughout California and in Oregon, is a regional problem that can be kept at bay by some judicious pruning or the application of a growth inhibitor, Harrington said.

He points to the scarring on the bark of trees where mistletoe has been removed.

"It's like a cancer," he said.

The white oak is particularly susceptible, but the parasite can be found on other species as well.

Although mistletoe can eventually kill an oak or weaken it to the point where it can fall over, Harrington said the trees are fairly resilient and can bounce back if cared for.

He showed pictures of an oak that was almost completely engulfed in mistletoe. The parasite was cut away and the tree is thriving.

However, even after the mistletoe is removed, the roots remain in the tree and will grow back.

The city prefers to cut the misteltoe, but a growth inhibitor known as Florel can be applied. Harrington said the problem with applying the inhibitor is the mistletoe can be high up in the tree and the surrounding foliage has to be protected.

Reach reporter Damian Mann at 541-776-4476 or e-mail

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