What Wisconsin Nurseries
Need to Know Before Selling Barberry: Black Stem Rust Quarantine and Invasive Species Restrictions
Black Stem Rust (Puccinia graminis) is a fungus of bread wheat, durum wheat, barley and triticale crops. The rust also infects oat, rye, orchard grass, timothy, fescue, ryegrass, blue grass, Mahonia or Mahoberberis evergreen shrubs, and other wheat relatives. Black stem rust (BSR) can be found worldwide. It thrives in moist areas and during wet seasons, causes significent damage to wheat crops across the continental U.S. If you suspect you have found black stem rust on barberry, cut a sample of the affected branch and submit it to your local Extension county office. Be aware there are many common rust diseases found on grasses.
Since the fungus alternates between cereal grains and barberry or Mahonia hosts; common barberry and BSR-susceptible or untested cultivars of Japanese barberry are prohibited (i.e. can't be sold or possessed) by the black stem rust quarantine in protected areas of the United States, including Wisconsin.
Invasive Barberries
The common barberry (Berberis vulgaris) is a non-native woody perennial bush that was introduced into the United States by European settlers. Considered invasive as early as the 1700s, common barberry is classified as a prohibited invasive species under NR 40 by the Wisconsin Department of Natural Resources. This means it can't be sold or present on the landscape in Wisconsin, in order to prevent it from forming dense stands, dominating native forest understories and shading out native plants. The closely-related Japanese barberry (Berberis thunbergii) is an NR40 restricted invasive species, with some exceptions. Some barberry cultivars are considered non-invasive and can be sold and planted in Wisconsin, provided that they are included on the federal list of BSR-resistant barberry varieties. Every barberry on the federal list has been tested at the cereal disease lab and proven to be rust-resistant.
Black Stem Rust Quarantine Requirements and Invasive Species Regulations
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