It's associated with old-world pomp, intellectualism and collegiate architecture. Hallowed in literature, lauded in poetry and adorned in art, it even has its own league.

It's associated with old-world pomp, intellectualism and collegiate architecture. Hallowed in literature, lauded in poetry and adorned in art, it even has its own league.

But botanist Kristi Mergenthaler looks at English ivy and sees little more than another pervasive, invasive species in Southern Oregon — like Himalayan blackberries, but without the benefit for cobblers and pies.

"Even the berries on English ivy are mildly poisonous," says Mergenthaler, from the Southern Oregon Land Conservancy. "But it's non-native, has no predators and really takes over wherever it grows. It forms an ivy desert to a point where nothing else can grow around it.

"Although, I must say that Norway rats like to nest in it," she says.

Still, that's not a good enough reason to stand by and watch English ivy replace native plants in places such as the Jacksonville Woodlands, which are the next target of a de-vine intervention by Mergenthaler and other native plant-o-philes.

The conservancy is organizing a Saturday volunteer work party to pull and remove invasive ivy from parts of the woodlands where the plant is taking over, threatening to kill oaks and other native trees and shrouding the riparian areas of Jackson Creek.

"If you're in Western Europe, it's a wonderful plant," she says. "But it has predators and diseases that keep it under control. Here, not so much."

But in the woodlands, English ivy finds its nemesis.

Predator, thy name is Mergenthaler.

"Constant vigilance," Merganthaler says. "That's what it takes to control invasive species."

Like many invasive plants, English ivy came to North America as an ornamental plant and over time it's been spread systematically, either by people planting it in gardens or birds carrying seeds.

It grows year-round and tolerates shade, allowing it to smother competing plants by hogging water and soil nutrients. Once it establishes itself on the ground, it sets its viney sights on climbing and eventually cloaking trees, often fatally.

"You can have death by ivy when it tops trees," she says. "The weight of it can also make trees fall over."

The Oregon Department of Agriculture in 2010 banned the sale and transportation of English ivy, making it illegal for anyone to plant or cultivate it.

It still, however, can be found in gardens and woodlands such as Jacksonville's as well as many backyards.

The best way to rid a tree of ivy is to girdle it, Mergenthaler says.

Starting waist-high on a tree, cut and pull all the ivy around the tree, then work your way down to the ground. Then clear the ivy around the tree.

Then repeat diligently and vigilantly, she says.

"Eventually, after a number of years, you can have an ivy-free area," she says.

Bob Budesa, a Jacksonville retiree who once ran the noxious weed program for the federal Bureau of Land Management here and is known locally as the Weed Wrangler, says he's tried various herbicides on the woodlands' ivy, particularly near the Britt grounds, but so far has been unsuccessful.

"I've really tried to lay it on but it didn't seem to work," Budesa says.

The waxy leaves seem to keep herbicides from soaking in, Budesa theorizes. He's thinking one possible path to ivy-cide would be taking a weedeater to the vines, exposing leaves and stems for chemical treatment.

"Flail the hell out of it, then spray it," Budesa says. "I may actually give it a try this spring."

Reach reporter Mark Freeman at 541-776-4470, or email at