Pretty to see, but the 'stinking sumac' is a pest

JANN HENDRY/Acorn Newspapers A WEED BY ANY OTHER NAME-Old Agoura homeowner Robert Evren removes Ailanthus from the hillside behind his home. Evren has hired a team to remove the tree that, lovely as it may be, grows wild, sucks gallons of water and wreaks havoc on native plants. Evren also plans to direct a team to eradicate the species from park property. Much to his dismay, the tree continues to be planted everywhere-including the Agoura Hills/ Calabasas Community Center. Robert Evren may think the Ailanthus altissima trees that proliferate on the parkland property next to his Old Agoura home are beautiful, but he knows looks can be deceiving.

Evren recently paid a crew $500 to remove several of the trees from Santa Monica Mountains National Recreation Area parkland adjacent to his property.

Names can also be deceiving. Though the tree is known as the tree-of-heaven or Chinese sumac, Evren and many botanists think Ailanthus should be renamed the tree-from-hell since it is so invasive, crowding out native trees.

"Ironically, the Ailanthus is actually very pretty," Evren said. The trees have fronds that flutter gently with the slightest breeze, smooth stems and pale gray bark. They even produce clusters of small yellow-green flowers near the tips of their branches.

Pretty or not, the tree's ecological value is nil, Evren said, and Ailanthus does not support birds or insects as oaks or pines do.

And its beauty belies its thuglike tendency to stake out territory where it bullies other trees, such as valley oaks, to death. Just like the well-dressed mafioso, the attractive tree cannot hide its intention to rob the ground of water. Its massive roots must be surgically removed or else a few trees will quickly turn into a grove.

Besides the enormous roots that suck up precious water, the tree-of-heaven smells like rotting peanut butter, Evren said. The stench has earned the tree another name-stinking sumac.

Just a tree or two can quickly produce a forest, and Ailanthus needs little water, doesn't mind pollution and can thrive almost anywhere, including broken city sidewalks.

Ailanthus has flourished in the United States since it was reputedly introduced in Philadelphia, Pa. by a Chinese gardener in the late 18th century. It now grows wild in California gold country, where it was planted in the 1800s.

Randy Philips, a restoration biotechnician and a park ranger for the Santa Monica Mountains National Recreation area, was on hand when Evren had the trees cleared next to his home. Philips said the tree puts out "tons of seeds," about 100,000 per tree, which "float and spiral in the wind like a helicopter."

Entire groves can be spawned by the seeds from one tree, and they also spread by suckers and in other ways.

Philips said the Ailanthus trees can be mowed down but the roots keep growing. "They're tough to get rid of."

Evren said the roots can grow underneath concrete. To kill the hardy trees, notches must be cut into the bark and filled with pesticides.

"Small saplings will attack full-grown trees," Evren said. He added that in its native China, the tree is much less unruly.

Although it is appreciated in its native land, Ailanthus has been both reviled and revered in the U.S. It was the Ailanthus that was featured in the movie, "A Tree Grows in Brooklyn," yet East Coast botanists liken the trees' rampant growth to a plague.

Evren says he was happy to pay for the trees' removal. He just hopes the invasive, stinking trees won't return next year.