Old man's beard is a rapidly growing vine which poses a threat to New Zealand's native bush and in Otago grows in gardens, hedges, and along roadsides and river banks.
It kills supporting plants, prevents regeneration by blocking out light and can produce 1000 seeds per square metre. Under Otago's pest management strategy, land occupiers are required by law to destroy any old man's beard on their land.
The regional council inspected 172 properties in Dunedin targeting those found to be non-compliant in 2012 and known problem areas, a recent report to council said.
Results had been ''promising'', with 30% of the properties now fully compliant.
However 50% had minor non-compliance and 20% major non-compliance.
Properties found to be non-compliant would be re-inspected in coming months, it said.
Many of those properties had absentee landowners so letters were sent to them requesting control be completed within 21 days before re-inspection.
In Central Otago and the Lakes district, most landowners were aware of infestations of the plant, but often failed to undertake full control or follow-up control, the report said.
That had caused re-infestations and, as a result, properties remained non-compliant.
''Ongoing monitoring will be required.''
Infestations found on Department of Conservation and Land Information New Zealand land were reported to them.
