Japanese Barberry  (Berberis thunbergii)
has been on the USDA invasive species list since the 1980s. With its high seed production and 90% germination rate, this plant has taken over forest floors, wetlands and open spaces at an alarming rate. It is now found in the wild in 31 states; throughout all eastern and mid-western states, and areas of Wyoming and Washington.

Recently an alarming side effect of this plant’s escape into the wild has been discovered.  Japanese Barberry creates a humid microclimate creating a highly favorable environment for tick survival and reproduction cycles. This humid environment is especially suited for Deer Ticks (aka: Blacklegged Ticks) ( Ixodes scapularis), vectors of Lyme Disease!   And indeed, studies show Lyme Disease has increased where Japanese Barberry is prevalent.  This plant’s encroachment has now created a public health issue, which has BLM, USDA, and Agriculture Mangers  stepping up efforts to eradicate it in the wild.

Public education is key to controlling invasive species, but inexcusably this highly invasive shrub is still sold in nurseries and written about in garden magazines and nursery catalogs publicizing it as a suitable plant for urban landscapes!  Many states now prohibit the sell of Japanese Barberry, but they are still sold in Oregon, so please research plants before you buy them.  Be a Conscientious Gardener!

Invasive Plant Atlas:  https://www.invasiveplantatlas.org/index.html

Entomology Today: https://entomologytoday.org/2017/10/04/the-5-year-plan-manage-japanese-barberry-to-keep-tick-levels-low-reduce-lyme-risk/

Scientific American: https://blogs.scientificamerican.com/guest-blog/barberry-bambi-and-bugs-the-link-between-japanese-barberry-and-lyme-disease/

Oregon Invasive Species: http://www.oregon.gov/ODA/programs/Weeds/OregonNoxiousWeeds/Pages/AboutOregonWeeds.aspx

Article by: Carlotta Lucas