Weed identification and removal
Asked June 18, 2018, 1:58 PM EDT
Hi, I am looking for help in identifying the large weeds with spines on stem and white flowers shown in the picture and removing it. There are numerous stems growing several feet high and I'm looking for the best way to get rid of it.
You've got blackberries, specifically Himalayan Blackberry, Rubus armeniacus. These are invasive in our area rather than a native plant, though they are naturalized into nearly every landscape in Washington County. Removal will be a multiple-year project but can be successful. There are mechanical and chemical methods or use a combination of them. The time of the year matters, so follow the guidelines in these publications.
Methods to control blackberry thickets: https://extension.oregonstate.edu/node/81706
Blackberries: Friend or Foe?: https://extension.oregonstate.edu/pests-diseases/weeds/blackberries-friend-or-foe
Himalayan Blackberry (Tualatin Soil and Water Conservation District) : https://www.swcd.net/invasive-noxious-weeds/himalayan-blackberry/