Tecomastans (yellow bells/geelklokkies) is a listed Category 1b alien and invasive plant species in terms of the 2014 Alien and Invasive Species Regulations of The National Environmental Management Biodiversity Act (NEMBA) (Act No. 10 of 2004). Land owners are compelled to control and eradicate it as far as possible from their properties.

Origin:Tecomastans is native to the tropical Americas (e.g. Southern USA, Mexico, Ecuador, Peru and the Caribbean) and has invaded the eastern parts of South Africa. It was introduced as an ornamental shrub due to its showy, long-lasting yellow flowers, fast growth and hardiness as a hedge plant. It is the national flower of the Bahamas.

Tecoma stans (yellow bells/geelklokkies)

Description: It is considered a shrub or small tree up to 6m in height, which is mostly evergreen. The compound leaves are bright green (paler below) with is sharply toothed leaflets (5-13). Bright yellow trumpet-shaped flowers are borne in spring, throughout summer, in terminal sprays, maturing into brown capsules (12-20cm long) splitting open to release multiple papery-winged seeds dispersed mostly by wind and urban storm water systems.

As a frost-tolerant and drought-hardy shrub, it invades disturbed areas such as roadsides, railway lines, wasteland, open spaces, domestic gardens and water courses. Seeds are highly viable with a germination rate up to 90%. It forms dense stands that eliminate indigenous vegetation, altering ecosystem structure and functioning.

Tecoma stans (yellow bells/geelklokkies)

Control methods: Tecomastans is a difficult plant to control, as there are no registered herbicides for the plant. It produces many new stems when cut down. Mechanical removal (pull out with tree-popper; dig out; cut down; ring bark) is advised, in combination with general herbicides, until the plant is eradicated. The Agricultural Research Institute’s Plant Protection Research Institute has identified two biological control agents (fly and beetle), but the degree of damage caused by these agents are negligible and still under evaluation.

Indigenous alternatives: In natural areas, invasive species should not be replaced by other plants not occurring naturally in the area. In domestic gardens the following shrubs with yellow flowers can be planted:  Tecomariacapensis (Cape honeysuckle/Kaapsekanferfoelie), Rhigozumobovatum (yellow pomegranate/geelberggranaat), Bauhinia tomentosa (yellow Bauhinia/geelbauhinia), Grewiaflavescensn (sandpaper raisin/skurweblaarrosyntjie); Grewiaflava (velvet raisin/fluweelrosyntjie), Ochnaserrulata (small-leaved plane/fynblaarrooihout), Hypericumrevolutum (small-leaved curry bush/kleinblaarkerriebos).

Tecoma stans (yellow bells/geelklokkies)
Foto’s: Petro Lemmer

Visit www.invasives.org.za for more information on alien and invasive plant and animal species.

This article was sponsored by Seringveld Conservancy