Greenbriers Smilax

Ohio State's Firewise guide assigns generic greenbrier a high flammability rating, and North Carolina's extension guide places the genus in its high-flammability table. Those regional warnings matter when a plant is sold simply as greenbrier. A favorable assessment for a specifically identified member does not erase them.

For rough bindweed, Smilax aspera, Valencia recommends the plant among its native or forest climbers for low-flammability gardens. Girona's pirogardening guide calls the species very recommended for gardens at the wildland-urban interface. Its profile combines low watering frequency with high pruning frequency and calls for well-drained soil. The positive garden assessment therefore comes with upkeep, rather than permission to leave the climber unmanaged.

Sources differ over roundleaf greenbrier, Smilax rotundifolia. Virginia assigns it low flammability. A cone-calorimeter study, however, names roundleaf greenbrier among the plants with high effective heat of combustion. The researchers tested conditioned foliage and twigs at 25 kW/m². That result concerns heat released by burning samples; it does not provide a garden planting distance or reproduce Virginia's landscape assessment.

For the genus, the practical distinction is between a named Mediterranean selection with care requirements, a roundleaf species with unlike landscape and laboratory findings, and generic greenbrier warnings. Identify the vine before choosing which guidance to apply, and retain the source's regional setting and maintenance conditions.