Agapanthaceae - Agapanthus praecox 

What does it look like?

Agapanthus grows as clumps of arching, strap-like green leaves with a watery sap. It has thick, long, white rhizomes (roots), and produces purplish-blue or white flowers on top of tall stalks during summer. The seeds are held within a 3-sided capsule that is about 5cm long.

Agapanthus flourishes in coastal, frost-free (or lightly frosted), temperate climates and is commonly cultivated in public and private gardens. It grows wild in urban areas, on roadsides, coastal cliffs, stream edges and forest margins.

Why is it a problem?

Agapanthus tolerates a wide range of soil types and growing conditions, forming dense monocultures that exclude native plants and modify plant communities.

Strong, fleshy roots spread underground to create large clumps and it can also re-grow from root fragments. Plants mature quickly, producing large numbers of seeds (up to 4,000 per flower head) that germinate readily.

Control Methods

Herbicide control

  • Cut and stump treat with Vigilant® gel; or 
  • Spray with 60ml triclopyr (300g/l e.g. Grazon) +10ml penetrant per 10 litres water or 200ml dicamba (100g/litre e.g. Banvine) + 10ml penetrant per 10 litres water. Dicamba is also available in a number of other products in garden centres, hardware and farming stores at different concentrations..

Two or three repeat applications will be necessary at 6-8 week intervals for effective control.

Physical control

  • Removal of the bulb-like base of the plant by hand is effective.

Related Links