Report #1972 - Report: American Pokeweed (Phytolacca americana)

American Pokeweed (Phytolacca americana) on Sep 1, 2016

Submitter has sample
EDRR Status: Local expert notified

Description of specimen

I found what I thought was knotweed at first all through out my neighbor's back yard. We tried to dig up as much as we could and have been pulling up shoots ever since. Originally there was over half a 64 gallon trash can worth cut up material. There were shoots as tall as 5 or 6 feet and since we've pulled stocks as tall as 3 feet down.

Commentary

Hey, Benjamin. Thanks for the report. Yeah, pokeweed is pretty impressive that way. We looked at a patch in SW a few years ago with stems well over my head!

The story on pokeweed is that it is widely-enough distributed that it's beyond Early Detection's ability to manage in Portland. Sadly, that means it's up to residents and property owners to care of (like so much else). On the other hand, there are no requirements for folks to do so. We certainly encourage residents to do what you're doing, and suggest only that berries and roots go in the garbage. That should minimize the chances of some tough fragment surviving the composting process and popping up elsewhere. Stems, leaves, and green berries likely don't pose any risk.

Thanks again for checking in. Feel free to reach me directly at mitch.bixby@portlandoregon.gov.

-Mitch

Mitch Bixby
Sept. 2, 2016, 1:54 a.m.

Remedy

American pokeweed is an herbaceous perennial plant—above-ground stems die back completely each year but below-ground roots remain and can be very large, allowing plants to persist for years. Therefore, the entire root must be killed or removed, although getting every root fragment every year is nearly impossible. Expect full eradication to take 3-5 years. Also, be aware that pokeweed can make you sick if ingested, with roots most likely to be fatal.

Management comments: --Small infestations (few plants): If possible, dig entire root and throw in garbage, not compost. --Medium to large infestations (many plants): Dig roots, if possible. If not, apply herbicide in spring to early summer shortly after plants appear above ground. Carefully check label recommendations for safe and legally allowable volumes of herbicide you can apply. --In late summer and fall, plants will have purple to black fleshy fruits containing seeds. Herbicide application can be quite effective in late summer and early fall.
--In all cases, cut fruit-bearing stems and dispose of in the garbage, not compost. This prevents the berries from making new plants.

NOTE: Remember where the plant is! When it reappears in the spring, you can start working on it while the soil is still wet.

American Pokeweed (Phytolacca americana) on Sep 1, 2016

Description of specimen

Commentary

Remedy

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Location

Expert Reviewer