Butterfly Bush

Buddleja davidii

Family: Buddlejaceae

Type of weed:

Flowering Months: , ,

Description

A perennial, semi-deciduous, multi-stemmed upright shrub with arching stems usually growing 1-3 m tall, with square stems.

The oppositely arranged leaves (4-20 cm long and 1-8 cm wide) are elongated in shape with finely toothed margins. These leaves have dark green hairless upper surfaces and greyish-green velvety hairy undersides.

The flowers are mauve or purple (occasionally white to dark purple) with orange-yellow mouths. Flowers are small and tubular (8-1 mm long) borne in dense clusters (12-30 cm long) at or near the tips of the branches.

Fruit is an elongated capsule (5-10 mm long) with two compartments.

Dispersal

Seeds are mainly dispersed by wind and water, but also by machinery, vehicles, the movement of soil, and by dumping.

Impact on bushland

Buddleia can grow almost anywhere, but prefers nutrient-rich watercourses and creeklines, where it quickly dominates, shading out and replacing native plant species.

Distribution

Alternative planting

Native plants

  • Mint bushes  (Prostanthera incana, P. caerulea)
  • Native Indigo (Indigofera australis)
  • Grass Trees (Xanthorrhea spp)

Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.

There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.

Control

  • Seedlings can be hand pulled if all the roots can be removed.
  • Dense beds of seedlings can be sprayed with a herbicide.
  • Larger plants can be stem injected.

As berries are spread by birds, it is best to reat plants before they fruit. Bag any fruit or seeds and dispose of, preferably in a hot compost to kill the seeds. Other parts of the plant can be spread out to dry off the ground. Once the material is dead it will decompose in place or can be composted.

This plant can layer if cut stems are left on the ground.

For key points on these techniques:

  • See Weed Control Techniques
  • See Risks associated with control

For more info

For key points on these techniques: