Why it is a pest plant
|Production threat||Environmental threat||Public threat|
Boneseed is a fast growing bushy shrub up to 3m tall. Seed germination can be triggered following bush or scrub fires.
- Yellow daisy-like flowers from September to February.
- Clusters of small fruit that turn from green to black when mature.
- Seeds are bone-like in colour and extremely hard.
- Produces up to 50,000 seeds annually.
- Leaves grow in opposite pairs or whorls along a stem.
Boneseed poses a threat to low coastal vegetation, where it can rapidly replace native plants. It shades out seedling trees like pōhutukawa that need a lot of light to survive. Its thick growth can also restrict people’s access to beaches.
Boneseed can be difficult to control because of the large numbers of seeds it produces, which can remain dormant in the soil for up to 10 years. Birds and possums eat the fleshy fruit and spread undigested seeds into neighbouring shrub lands and coastal forests.
A native of South Africa, boneseed was first brought to New Zealand as an ornamental plant but its spread has seen infestations found around many parts of the Coromandel Peninsula including Whiritoa, Whangamata, Cooks Beach, Coromandel Town and Port Jackson. It also occurs on the west coast around the townships Raglan, Kāwhia and Port Waikato. Boneseed grows best in dry and sunny conditions in coastal areas, cliffs, sand dunes and wasteland. It doesn’t like heavy shade or wet soils.
Responsibility for control
All landowners/occupiers in the Waikato are responsible for controlling boneseed on their properties and are required to work with Waikato Regional Council in areas where control programmes are in place. Boneseed is also banned from being sold, propagated, distributed or included in commercial displays.
How To Control Boneseed
Basal treatment of trunk
Apply with a low pressure sprayer using solid cone nozzle or a paintbrush. Liberally treat the full circumference and the basal parts of the shrub or tree trunks in a manner that thoroughly wets at least 2-3 times the diameter of the lower stem or trunk including the root collar area.
Cut stump treatment
Cut stems at ground level and immediately coat the stump liberally with herbicide to cover the top and sides of the stump.
Cover all leaf surfaces with herbicide where stump cutting is not practical. Best results are achieved from spring to autumn.
Safety when using herbicides
- Follow the instructions on the manufacturer’s label.
- Always wear protective clothing.
- Always minimise the risk to your other plants.
- Contact the supplier for further advice.
Disclaimer: Any product names mentioned below are not an endorsement nor are they a criticism of similar products not mentioned.
Summary of herbicides and application methods for control
|Glyphosate||Cut stump treatment/spray application.|
|Metsulfuron||Cut stump treatment/spray application.|
|Triclopyr||Cut stump treatment/spray application.|
|Triclopyr/picloram mix||Cut stump treatment/spray application.|
|Picloram gel||Cut stump treatment.|
|X-Tree Basal ®||Basal treatment of trunk.|
|Herbicide rules will apply. You may need to notify neighbours if spraying. The Waikato Regional Plan explains the agrichemical (herbicides) use rule in section 6.2|
After initial control, it’s important to:
- clean out the site again at least annually to control regrowth
- stop weeds invading by replanting with non-pest plants (preferably native plants) once regrowth is no longer a problem.
- For advice and additional information on control methods, call our pest plant staff on freephone 0800 BIOSEC (0800 246 732).
- Chemical company representatives, farm supply stores and garden centres can also be good sources for advice.
View, download or order the following publications or call our freephone 0800 800 401.
- National Pest Plant Accord (Manual of plants banned from sale, propagation and distribution) ($10.00 plus GST)
- Plant Me Instead! (Plants to use in place of common pest plants) (free)
- Waikato Regional Pest Management Plan (RPMP) (free) (Section 5.8, page 56)
- Waikato Regional Council pest guide (free)