Spring flowering, iris-like perennial growing in tight clumps <45 cm tall. Stems flattened, slightly winged. Stiff, upright, sword-shaped leaves with parallel veins, folded in reddish-purple based fans. Deep blue flowers in clusters of 5-7 open only in bright sunlight.
Roadsides, tracks, open forest e.g. kauri, in extensive patches. Most common in North Auckland.
Seeds prolifically, dispersed by wind or gravity.
Extensive patches out-compete native species.
Difficult to eradicate once established as seeds prolifically. Clear roadsides, tracks & streamsides first, then move into bush. Follow up annually. Maintain weed hygiene, especially on tracks.
1. Dig out small patches.
2. Weed wipe, spring-autumn (1g metsulfuron + 150ml glyphosate + 10ml penetrant/1L).
3. Spray spring - autumn (3g metsulfuron + 150ml glyphosate + 10ml penetrant/10L).
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.