What does it look like?
An evergreen, legume-like shrub under 2 meters tall, with young shoots covered in short, curly hairs, while the rest of the plant is hairless. The smooth, woody stems are extensively branched, bearing oval leaves 15–30 mm long arranged alternately along the stem. From January to December, short clusters of sweet-pea-like flowers (15–17 mm long) appear at the ends of stems. The three-petalled flowers are purple with green on the outside of the side petals. These are followed by flat, heart-shaped seed capsules about 10 mm long, containing hairy, dark brown seeds approximately 5 mm long.
Fast growing, it shades out low-growing coastal shrubs, and produces many, very long-lived seeds. It tolerates salt, wind, drought, hot to moderately cool temperatures, poor and rocky soil, fire, and damage, but intolerant of moderate shade and frost.
Seed is spread in soil and water movement.
Why is it a problem?
Sweet pea shrubs form dense stands, discouraging the establishment of native species. Although it’s short lived, it’s replaced continuously from seedbanks.
It’s likely to invade shrubland, bluffs, short tussockland, bare and rocky land, all on coastal areas, seldom weedy inland.
Control methods
Physical control
Hand pull small plants all year round or mulch. You can also slash larger plants in regenerating shrubland (summer) and mulch.
Herbicide control
- Stump swab (all year round) using metsulfuron-methyl 600g/kg (1g/L) or a product containing 100g picloram+300g triclopyr/L (100ml/L). Or,
- Spray (larger infestations) using glyphosate (100ml/10L + penetrant).
- Cut stumps occasionally resprout and seed germinates in bare areas, especially after fires. It’s easy to kill, however seedling regrowth is usually extensive, so allow for ongoing follow up. Eradicate systematically, working downhill or in blocks along coastline. Replant where possible.
- CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
Related links
Management Programme
National Pest Plant Accord (NPPA)
The NPPA is designed to prevent the sale, distribution and propagation of a set list of pest plants (the Accord list) within New Zealand. If allowed to spread further, these pest plants could seriously damage the New Zealand economy and environment.
More informationUnwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
Taxonomies
FamilyPolygalaceae
TypePlants
GroupShrub
HabitatLand
Management ProgrammeNational Pest Plant Accord (NPPA)Unwanted Organism
