Final question (maybe)

Asked July 17, 2020, 3:00 PM EDT

You folks previously identified spurge, liverwart and pearlwart, and suggested remedies. One more difficult weed is in the attached photo. It throws seeds and spreads quickly. I have been chasing it with Roundup. Any other suggestions? Is a pre-emergent a good idea?
Thanks.

Marion County Oregon

1 Response

Thank you for the image.

This little weedy rascal is little bittercress, Cardamine hirsuta, a weed that's widespread throughout the metro region. It's an annual which, as you've noticed, shoots its seeds far and wide. Left to its own devices, "one bittercress plant can produce up to 5,000 seeds in just 5 weeks."

Bitterness can germinate nearly year-round, but is most problematic from fall through spring.

Persistence in removing it every time you see it will help to decrease the population in your yard and garden. I doubt anyone has been successful in eradicating it from their property.

"Common Weeds in Oregon Container Crops" is written for large-scale growers but should also be useful to you - https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em8874.pdf.