Fatoua villosa - I am losing

Asked September 13, 2017, 10:11 AM EDT

I've been battling a very aggressive weed in my perennial bed all summer. I think after much consultation with the internet that the plant is Fatoua villosa / mulberry weed. I have been spraying the emerging green shoots with glyphosate all summer, which kills the shoots, but it keeps returning. It has tremendous runners/roots crisscrossing my bed. I decided to pull up the root below one little shoot - picture attached. The entire bed was created, tilled, amended, planted/mulched in Fall of 2015, and I saw no evidence of it then, so I think it was a stowaway on some nursery plant. If someone could confirm that this is what I am dealing with and provide any suggestions as to how I might eradicate it (without destroying all of my perennials) I would be very appreciative. Thank you Gary

Orange County North Carolina

3 Responses

Hello Gary,

Thanks for a great question....Here is a link to a wonderful article from Delaware Cooperative Extension. http://extension.udel.edu/factsheets/mulberry-weed-fatoua-villosa/

For convenience, I've cut and pasted the control paragraph....

Control
Suspected mulberry weed should be removed from garden beds or pots and be discarded in the trash, not composted nearby. The plant produces abundant numbers of seeds, so it should be treated with herbicide or rogued out before it sets seed. A two to three inch layer of mulch can prevent most seed germination, as can pre-emergent herbicides. Post-emergent herbicides would also be effective.

Thank you! I am not that familiar with how pre-emergent herbicides work. Is it safe to put those on a bed full of lots of perennials - i.e. will they harm my many perennials coming up in the spring?

How do preemergence herbicides work?

It’s a common misperception that preemergence herbicides kill seeds directly. Instead, when sprouting seeds encounter the herbicide, cell division in the young root system is inhibited, resulting in death of the young seedling. These products generally do not control established vegetation, so it’s important to remove existing weeds from the site prior to applying the preemergence herbicide.

Perennials that are already established (only dormant) are not at risk, however, the new seed they may have produced prior to going dormant are at risk.

Another link for reading from Cooperative Extension (from Nevada).

https://www.unce.unr.edu/publications/files/ho/2011/fs1167.pdf