The bane of many backyards and shaded bushland areas, Wandering Trad (Tradescantia fluminensis) has frustrated many of us for decades.
It may look nice trailing out of a hanging basket with a few delicate white flowers, but every leaf, stem and piece of this plant is capable of regrowing when broken. Fragments quickly take root in shady spots and before you know it this silent invader has smothered the ground and everything in the understorey.
Trad grows best in moist, shaded situations in forests and along waterways, but may grow in full sun once it has become established. Trad outcompetes most other groundcovers and will form a thick layer that prevents other plants from germinating, leading to a reduction in biodiversity and habitat. It can also cause skin irritation in humans and animals.
Trad is a succulent creeping plant that roots weakly along the stem, with pointed leaves that are broad at the base and wrap around the stem. Leaves are dark glossy green and up to 5cm long, though variegated forms also exist. It can produce white flowers with 3 petals in spring and summer, but does not produce seeds in Australia.
Don't confuse with a native
Wandering Trad looks similar to a native groundcover known as Scurvy weed (among other names), or Commelina cyanea. Scurvy weed has stronger roots, small hairs along the stem, lighter and narrower green leaves and bright blue flowers. It can be useful in replacing Trad but can itself appear weedy at times.
The good news for managing Trad is the discovery and successful release of a smut fungus (Kordyana brasiliensis) that infects all parts of the plant, leading to its decline. This biological control is specific to Wandering Trad and doesn’t affect similar native plants. The smut fungus has been cultivated by CSIRO and released in trial plots along the east coast, often in conjunction with Landcare groups. It has successfully taken hold in several Trad patches in our area and given the right conditions can start to reduce the size of infestations within 2 years. With careful monitoring and transplanting of infected Trad stems it is hoped that we can maintain the presence of this bio-control agent in the area, leading to a big decline in Wandering Trad populations over time.