What does it look like?
Blackberry is a scrambling, very thorny, semi-erect shrub that is usually deciduous (loses leaves), with large root crowns and long suckers. Stems are usually arching (occasionally semi-prostrate), entangled, green or red and occasionally layering. Variously shaped (usually cut-edged), flat leaves are arranged alternately on the stems. White to pink 5-petalled flowers appear from November to April followed by clusters of black berries from November to May.
Why is it a problem?
Blackberry forms dense, long-lived clumps. Low plants scramble over the ground with an extensive rhizome system, occasionally layering and seeding. It tolerates most soil types, drought, and flood, but is intolerant of dense shade. Blackberry is mostly spread by rhizomes. Birds distribute seeds but they have a low germination rate. The plant has low to moderate damage in open habitats. It smothers most low growing species, inhibiting the establishment of native plant seedings, and impedes access.
Control methods
Physical control
Dig out (small patches only) all year round. Dispose of root crowns and rhizomes at a refuse transfer station or burn or bury deeply.
Herbicide control
Small patches only: Stem scrape and paint with undiluted glyphosate immediately.
Small patches only: Cut and paint stumps with glyphosate 200ml-500ml per 10L water.
Large patches: Spray (summer-autumn, before leaves become brittle) with Metsulfuron-methyl 600g/kg (7.5g per 15L water). Or
Tordon Brushkiller (60ml per 15L water). Or Triclopyr 600 EC (60ml/15L).
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
More information
Blackberry is listed as a Sustained Control pest in the Hawke’s Bay Regional Council Regional Pest Management Plan 2018 – 2038 and is subject to Plan Rule 18 relating to the control of blackberry at property boundaries upon receipt of a complaint.
It is an offence to distribute, breed or sell Blackberry in accordance with Section 52 and 53 of the Biosecurity Act.
Related links
https://www.weedbusters.org.nz/what-are-weeds/weed-list/blackberry/
Management Programme
Sustained Control Programme
To provide for ongoing control of the subject, or an organism being spread by the subject, to reduce its impacts on values and spread to other properties.
Rules
Rule 18 - blackberry and gorse plants
All occupiers shall, on receipt of a written direction from an Authorised Person, destroy all plants within 10 metres of the property boundary; and on land that they occupy where an adjoining occupier is also destroying or the land is clear of, all plants within 10 metres of the property boundary; Council will administer the rule upon receiving a written complaint from the adjacent land occupier and/or at the discretion of the Authorised Person.
