Butterfly Bush

Buddleja davidii

Family: Buddlejaceae

Type of weed:

Flower colour(s): , ,

Priority Weed Local Priority Weed. (See more weeds of the class.)

Flowering Months: , ,


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.


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.


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.


  • Hand remove
  • Remove flowers, fruit, pods or seeds
  • Spray
  • Stem inject or frill

Manual control

Hand remove

Grasp stem at ground level. Rock weed backwards and forwards to loosen roots, then pull out gently. Carefully tap the roots to dislodge attached soil. Replace disturbed soil and pat down.

  • Leave weeds so that roots do not make contact with soil; on a rock, for instance. A small amount of debris may be hung in a tree or removed from the site.
  • Vary the position of your body to avoid fatigue when removing plants by hand over extended periods.

Remove seeds, pods or fruit

Gently remove any seeds, pods or fruit and carefully place in a bag.

Chemical control

Note: Herbicides that may be used for this weed include Glyphosate.


Please consult the Herbicide page of this website to help you decide whether to spray, how to do it safely and more.

Stem injection or frilling

Stem injection
Drilling holes at 45° and squirting poison into holes
Apply poison immediately after drilling

At the base of the tree, drill holes at a 45° angle into the sapwood (just under the outer bark) at two finger space intervals around the entire base of the tree. Repeat this process below the lowest branch


As an alternative to drilling, make cuts into the sapwood with a chisel or axe. Fill each cut/hole with herbicide immediately. Repeat the process at 3 cm intervals around the tree.


Plants should be healthy and actively growing. Deciduous plants should be treated in spring and autumn when leaves are fully formed. For multi-stemmed plants, inject or chip below the lowest branch or treat each stem individually. Herbicide must be injected immediately before the plant cells close (within 30 seconds before translocation of herbicide ceases.)

Specific control tips for this weed

  • 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 treat plants before they fruit. Bag any fruit or seeds and dispose of them, 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:

Local Priority Weed

Control measures:

  • The plant should be fully and continuously suppressed and destroyed.
  • Plants under 4 metres in height should be fully and continuously suppressed and destroyed.
  • The spread of this plant should be adequately contained to prevent spread impacting on priority assets. Weed notices will only be issued for these weeds under special circumstances.