Once valued for being hardy and evergreen, catclaw vine smothers understory plants and trees — now making it an invasive species.
Until the most recent spell of freezes, most trees around town continued to cling to their leaves. It was starting to look like winter might just pass us by this year. And then came a few frigid, icy days — and all the deciduous trees (and some semi-evergreen ones) lost their leaves. Turns out humans aren’t the only ones who dislike ice.
Now, only true evergreens like mountain laurel, Ashe juniper, live oak (technically not evergreen), cenizo, yaupon holly and agarita stand out in a sea of grey and brown.
This is a good time to take stock of other “backbone” plants like evergreen shrubs, groundcovers, grasses and vines as they can be particularly useful in a garden since landscapes look especially barren in winter without them.
In lieu of trees or hedges, evergreen vines climbing a wall or trellis may fill in the wintertime gaps. However, there are some non-native plants that were originally valued for being hardy and evergreen but have become problematic invasive species. Catclaw vine is one of them.
Catclaw vine (Dolichandra unguis-cati) belongs to the Bignoniaceae family, also known as the ‘trumpet creepers.’ Other notable plants in this family include esperanza, catalpa, desert willow, trumpet creeper (go figure), and crossvine. All sport showy trumpet-shaped flowers — catclaw vine may briefly produce yellow flowers in spring, often high up in the canopy of the shade tree it’s actively killing.
It’s a high climbing vine with glossy, lance shaped leaflets oppositely arranged along woody stems. Between the two leaflets there is a thin tendril with three flexible hooks, or ‘catclaws.’ These tendrils find their way into the bark of trees and the brick of houses and help propel the aggressive vine over 25 feet high and equally wide. Interestingly, the leaves growing along the ground are often broad and irregularly shaped, making it tricky to identify.
Unlike our native catclaw acacia, the claws on catclaw vine are much more gentle on the skin. (Good news when you go to remove it.) But in natural areas, especially riparian bottomland forests, catclaw vine smothers understory plants and even trees with its sprawling lateral habit and dense crown of canopy leaves. Examples of this can be found along the San Antonio River Mission Reach and the Incarnate Word Headwaters Sanctuary.
Left unchecked in natural areas or in your garden these exotic vines can easily take over so early removal is key. Stems of this plant readily root along the ground and eventually form large tubers that can be difficult to remove.
While there are chemical methods of removal, mechanical removal is recommended. Cut the top portion of the vine, pull up any stems growing along the ground and dig out the tuber. Either method will require repeated treatments so keep an eye out for resprouts.
If you like the look of an evergreen trumpet vine, a native alternative is crossvine. It shares many similarities but without the destructive tendencies of catclaw vine. An even better-behaved evergreen vine is the native coral honeysuckle.
