Weed of the Month: Smilax (Greenbrier)

Smilax vines go by the common names greenbrier or catbrier due to the thorns covering their stems. There are 300 to 350 smilax species worldwide. Approximately twenty-four species are native to North America, with fifteen species growing in South Carolina. Smilax grows well in moist shade and is an important food source and habitat for wildlife, including birds, rabbits, and deer.

Early American settlers made a root beer from the pulp of the smilax root by mixing it with molasses, sassafras, and either fermented corn or rice. Sarsaparilla, the drink of old cowboy movie fame, is made from a smilax species native to the Caribbean.

Jackson vine, Smilax smallii, is the only species recommended for homeowners to use ornamentally in the landscape. The vines have thorns located at the base, are mostly evergreen or semi-evergreen, and can grow over 30 feet. Generally, plants produce small clusters of black, grape-like berries, but a few species have red berries. Jackson vine is adapted to drier and sunnier locations and is usually introduced into the landscape by songbirds.

Smilax vines are difficult to control due to the carbohydrate reserves stored in their large tuberous roots. Tuber removal is challenging when vines are growing among tree roots. Herbicides can be used to control the vines but require multiple applications. For more information, please see HGIC Factsheet 2328, Smilax.