History & Introduction
Berberis julianae, commonly known as wintergreen barberry or Juliana’s barberry, is native to Central China. It was introduced into cultivation in the United Kingdom in 1900, and then initially introduced to North America as an ornamental plant shortly thereafter. It was first recorded escaping cultivation in 1984 and continues to be sold and planted today despite its invasive qualities. As a result, Juliana’s barberry is now an increasingly widespread invasive species in the US. In LIISMA, research grade observations of the plant have been recorded in Suffolk County and Brooklyn.
Identification & Biology
Juliana’s barberry is an evergreen shrub that can grow up to 9ft tall. The branches are yellow-brown to greyish with yellow shoots. The stems are covered with large spines at the nodes. The plant has leathery, lanceolate leaves that are alternately arranged along the stem. The leaves have spiny, toothed margins and are green in spring and summer, turning red in the fall. The plant produces small, white or yellow flowers that are noticeably fragrant and bloom in the spring. Small berry-like fruits are produced May through November, maturing to a bluish-black. Fruits are covered with a white waxy coating that can be easily rubbed off. White-tail deer (Odocoileus virginianus) avoid browsing barberry; these spiny shrubs are planted as a deer repellant and living fence in the horticultural trade.
Damage and Concern
Juliana’s barberry is a highly invasive Tier 2 invasive species listed for eradication on the New York State Invasive Species Tiers list. Juliana’s barberry forms dense, impenetrable stands that shade out native growth, has a high germination rate and abundant seed dispersal, and has large thorns that pose a safety risk. Similar to Thunberg’s barberry (Berberis thunbergii), which is widespread on Long Island, it is possible that Juliana’s barberry could also be a prime habitat for ticks.
Management & Control
Manual/Mechanical: Smaller plants can be pulled by hand, using long sleeves, gloves and protective eyewear to protect from the spines. Fruits should be bagged and removed from the site. Care should be taken to remove all roots to prevent resprouting. Spring is an optimal time for manual removal, as barberry plants are often the first plants to leaf out and its leathery leaves are distinctive. Larger plants can be cut down to the base and the stumps removed with maddocks and shovels, and potentially a small backhoe. All plant material should be bagged and disposed of off site, or in a large dumpster.
Chemical: For larger, more mature plants, it is likely they may resprout, so repeated manual and mechanical control combined with a cut stump herbicide treatment utilizing a solution of glyphosate, may be necessary for best results. A foliar application of herbicide after the shrubs are cut low and have resprouted is an option as well. It is possible that removal of the species will create space for other invasive species to take its place, so consideration should be given to planting native grasses, forbs, or shrubs in place of the barberry.
Monitoring & Reporting
LIISMA is currently monitoring Juliana’s barberry as part of our Early Detection and Rapid Response program. As reports of the species are collected, LIISMA is dedicated to delineating and managing any early emerging infestations of the species before they become widespread. Juliana’s barberry is currently a Tier 2 species on Long Island, prioritized for early detection and eradication.
Your reports matter to us– report the species to iMapinvasives as soon as you detect it.
Citations
Speith, E. (2012, July 12). Invasive Plant Alert: Wintergreen Barberry. doee. Retrieved April 20, 2023, from https://doee.dc.gov/
Gilman, E., Klein, R., & Hansen, G. (2022, July 18). Berberis julianae Wintergreen barberry. FPS65/FP065: Berberis julianae winterberry barberry. Retrieved April 20, 2023, from https://edis.ifas.ufl.edu/publication/FP065
