Endemic to Western Australia, bluebell creeper is an extremely invasive weed in woodlands and forests. The shrub smothers native plants by out-competing for sunlight or strangling them with their twining stems.
Description
Western Australian bluebell creeper (Billardiera heterophylla), also known as sollya, is a perennial climber with twining stems that grows vigorously reaching up to 3-4m in height. In open areas it takes on a shrubby form.
Leaves are light to dark green, glossy and hairless varying from 2-5cm long. They are alternately arranged on the stem, ranging from narrowly oblong to lance shaped. Flowers are pendant clusters of 2-5 small blue to mauve (sometimes pink or white) bell-shaped flowers 8-12 mm long. Bluebell creeper flowers from spring to summer. The creeper forms succulent green cylindrical berries to 3.5cm long becoming purplish green containing numerous seeds 2-3cm long.
Similar species
Can be confused with a number of local South Australian native species including Sweet Apple-berry (Billadiera cymosa), One-flower Apple-berry (Billadiera uniflora) and Yellow-flower Apple-berry (Billardiera versicolor). Confirm identification before controlling suspect weeds.
Impacts
Bluebell creeper rapidly outcompetes and smothers desirable plant species in native vegetation. Its vigorous twining stems smother the native understorey and ground cover layer also preventing regeneration of shrubs and trees.
Bluebell creeper contains toxins that can irritate the skin.
Distribution
Bluebell creeper has spread beyond its natural range having invaded Green Adelaide’s natural bushland areas. Seed is often dispersed by birds and other animals such as foxes that consume the fruit. The spread of bluebell creeper also occurs through disturbance of the soil seedbank following fire, soil movement or control efforts. The seeds can stay viable for ~5 years.
Control
Billardiera heterophylla (Bluebell creeper) is a declared weed under the Landscape South Australia Act 2019.
In Green Adelaide, the sale of plants or contaminated goods is prohibited.
Green Adelaide encourages control of plants where there is a risk to biodiversity assets.
Control methods
Bluebell creeper responds to disturbance with vigorous growth so monitor for regrowth after any control is applied and re-treat where necessary.
Hygiene
To prevent the spread of Bluebell creeper, clean garden tools or machinery before leaving an infested area. Do not move contaminated soil.
Manual
Pull seedlings by hand. Cut stems, remove rootstocks. Established plants may regrow. Minimise soil disturbance where possible as this can encourage other weeds to germinate.
Small amounts of cut material or hand pulled seedlings can be placed in thick, heavy duty garbage bags, double bagged and securely sealed then placed in a household waste bin.
Chemical
A herbicide for woody plants can be used to treat cut stumps when the plant is actively growing. Cut stems close to the ground and apply herbicide to the cut stem within 15 seconds with a dabber bottle applicator. Herbicide can also be applied by using a low pressurised spray pack.
Spot spray can be used on young plants or ground trailing plants. Applying in warmer months will give better results. Take care to avoid desirable plants and always check plant identification as similar native species look very similar.
For advice on chemical options please refer to Controlling declared weeds in SA.