We've had our house for a couple of decades, and every time I neglect the back yard (more often than I should) this weed pops up all over the place:

enter image description here

It has a skunky smell when bruised, grows from a single stem, and can get several feet high (perhaps higher). When I pull it up it's always attached to an underground root system that seems like it's coming from somewhere else. I'm guessing these roots are all over the place, and every time I pull up the plants they regrow from the roots.

Any idea what it is, and how I can permanently remove it and its brethren?

Edit: a closeup of the leaves:

enter image description here

Edit 2: a branch and seed pods from a 70' tree overhanging our back yard, in case anyone's interested (it doesn't particularly smell when bruised):

enter image description here


Maybe I am "projecting" here (because your photo could obviously be a lot of things), but this looks a lot like what we have in our yard (California, but I have seen this on the East Coast too).

The way you mention that it smells when bruised, and that it will get several feet high - maybe higher, reminds me of "Paradise Tree", sometimes called "Tree-of-Heaven" (!), "&*!!@ Peanut-Butter Tree", or Ailanthus altissima. Here is a picture of it from the website of Van den Berk Nurseries:

Ailanthus altissima, photo from Van den Berk Nurseries' Website

Here's its entry in the Invasive Plant Atlas of the United States. And, here's an evocatively titled article on it called "Tree of Heaven: A Devil In Disguise."

It's horrible. It grows about a foot a month (or faster!), eventually becoming an enormous tall tree. Also, yes to the underground roots.

Don't know how to eradicate it, but check into whether this is it, and good luck.

My current strategy is to try to stay on top of new arrivals of this pest ASAP. It is surprisingly easy for seedlings up to maybe almost 1/2 inch diameter, to just yank them out by the root.

Also since the tree grows so fast, as blacksmith37 notes in his comment, the wood is super soft, & I am able to pretty quickly cut off little trees up to 2-3 inches diam. with a hand saw and afterward paint thoroughly with "Vine and Stump Killer". (No, I am not selling this product, and it may not even be necessary, but I used it thinking it might help.) This is a photo of one of the stumps, somewhere between 1 and 3 yrs. after I chopped & painted it. Notice it doesn't seem to be re-sprouting, and it's not due to lack of water. Drought doesn't bother these guys.

enter image description here

  • Thanks. What other info should I post for better identification? (Is there a Meta Q&A about "how to ask for plant IDs"?) – Daniel Griscom Jul 27 '19 at 15:00
  • Multiple photos (different angles, parts of the plant, and stages of growth) can be helpful. – Lorel C. Jul 27 '19 at 15:04
  • 1
    I happened to look up in my back yard, and there's this overhanging 70' tree with leaves that look just like my original weeds. I added a picture of a branch to my Q; is this the same thing? (If so, makes "eradication" a bit more involved...) – Daniel Griscom Jul 27 '19 at 16:14
  • 2
    Absolutely the same (recognize the seeds). Ours also spawned by a humongous specimen in a neighboring yard. Pretty sure that 1 way they spread is by the copious crop of seeds they put out every yr. Recently I called a pro to chop some bigger ones in our yard, and vowed to try to keep ahead of them in future. I have been digging up small trees when I first see them emerge, and I notice in the vicinity of the big neighbor tree when I dig up a baby sprout it sometimes seems to be coming out of an already-huge root. This makes me think A altissimus also propagates by underground means: wicked. – Lorel C. Jul 27 '19 at 19:04
  • 1
    In case any of you are into literature the tree in "A Tree Grows in Brooklyn" is an Ailanthus. Just a fun fact for you. – Jurp Jul 28 '19 at 1:23

Your Answer

