Sunday, March 23, 2014

Villainous neighbors

Want to get a snarl out of a mild-mannered Oregon environmentalist? Just walk up to her and say, "English ivy".

If you are not in the know, you may think English ivy is a hardy, reliable, esthetically pleasing ground cover with glossy green, white-veined, three-lobed leaves. Even people who don't know many plants recognize English ivy and may have a vaguely romantic sense about it from an obscure Christmas carol, "The Holly and the Ivy".

But in Oregon, English ivy is an invasive plant that destroys habitat for other plants and kills trees -- yes, kills trees! -- by climbing all over them and smothering the tree's own leaves and adding considerable weight to the tree, making it more vulnerable to wind. It crowds out native plants, robbing small animals of their normal food sources (nothing, it seems, eats English ivy on purpose), and, left unchecked, will eventually Conquer the World. It's Oregon's version of the South's kudzu vines. (Actually, we've got two of those, English ivy and Himalayan blackberries, but Himalayan blackberries provide a delicious street-side snack every August, so it's hard to feel quite as much hostility to them.)

So why am I inflicting all this militant botany on you? Because the mountainside I have been celebrating since I moved in here is increasingly covered with -- you guessed it, English ivy. I went out this afternoon to examine the problem more closely, and there's a whole lot of the stuff clambering up the mountainside between the Terwilliger Plaza parking lot and the street that runs by above at about the ninth-floor level. Several trees already wear thick coats of English ivy, which is turning them into big broccoli spears where only the leaves at the very top of the trees manage to unfold. English ivy doesn't care about winter, at least not here, and its glossy green leaves and clinging vines persist year-round.

So where can I get more information about this, I was asking myself as I wandered beneath the cascades of English ivy? And voila! a fellow resident was pruning back dead fern fronds and had the answer for me: Steven Price, the Terwilliger Plaza groundskeeper, who is about to retire at the end of next month, but will be able to tell me probably more than I want to know about the local infestation of hedera helix (easier to think of it as noxious by its Latin name). Now it may be that we're leaving the clingy villain where it is because it's holding the mountainside in place. Someone characterized the rock constituting the mountain as "crumbling basalt", and I would prefer not to have to wear a hard-hat to walk to my car. Or it may be that the English ivy is serving some other arcane function other than coating the rocks with bright green leaves.

But if not, I'm curious to know what we're doing to get rid of it. It's on the state's list of noxious weeds, and if it's on our land, we're responsible for it.


  1. Will be interested to hear what you find out from the groundskeeper.

  2. You can "girdle" it by cutting a ring around the trees at the base severing the ivy from its root. This will not kill the ivy, but it will kill all of it about fhe "girdle".