Clematis tangutica (Yellow Clematis), 2024
watercolour on paper, 20” x 14”

A perennial vine native to mountainous regions of Central Asia and western China, Clematis tangutica is an example of a relatively new weed. It was introduced to North America as an ornamental garden vine and many Canadian provinces have yet to designate yellow clematis as an invasive. Despite its designation as Noxious in Alberta, it remains widely available for purchase through nurseries and online retailers under various common and cultivar names, particularly ‘Bill MacKenzie’, ‘Radar Love’, and ‘Helios’. Yellow clematis demonstrates how easily ornamental plants can escape cultivation and become invasive when care is not taken in what is sold and planted. 

Yellow clematis reproduces both by wind-dispersed seed and vegetatively from stem pieces. Fast-growing and highly aggressive, the vine will rapidly cover anything in its path. It has become a familiar feature in cities and on the landscape, its vines covering plants, fences, and structures. Once established, dense growth easily outcompetes nearby plants for sunlight, space, and water. To help prevent further spread, do not purchase plants or seeds labelled with any of the names listed above. If in doubt about what the plant is, it is best to avoid planting it altogether.