Need Help Identifying a Weed!

Asked May 11, 2016, 9:23 PM EDT

Hi, Could you please help me identify this pest. It keeps popping up in my yard. I can never pull it out completely, because the root twists and turns. Plus the root is very thick -- about as wide as my pinky! So I never manage to pull out the entire root. I'm not even sure how long the root is! In addition to identifying it, any advice on how to get rid of it would be greatly appreciated. Oh and my neighbor has the same problem in their yard -- which is adjacent to mine.

Multnomah County Oregon

1 Response

Even though you included images of your mystery weeds, the plants are in such condition that an identification isn’t obvious. It may be helpful if you submit new images after one of them grows out a bit, in a month or so.

My first thought is that the plants are reasonably common garden perennials which have gone rogue here in the northwest: Italian arum or Lords-and-ladies, its botanical name Arum italicum. The leaves may be all green or marked attractively with silver. If so, the news is gloomy. It’s extremely difficult to eradicate because of its deep fleshy roots, the small offsets which disperse when someone tries to dig it out, and the showy orange seeds which birds eat and then “release” along with a dose of freshly made fertilizer. Beyond that, herbicides don’t work. Comment has been made that it seems to thrive on glyphosate, the active ingredient in Roundup and other retail herbicides.

You may need to rely on starving the roots. You can do that by removing new growth every time you see it, perhaps every 2 weeks. Or you can try blocking all light with a dark tarp which you’ve secured in place with soil or heavy objects and, then, lift the tarp every several weeks to remove the long white stems growing toward the edges; replace the trap and weights, and repeat. Endlessly. Until it’s gone.

Success will require years of persistent effort.