Lantana camara has attractive yellow, pink and orange flowers, but is unwanted because of its poisonous characteristics and ability to grow to four-metre high dense stands to the exclusion of virtually all other plants.
Regional Council Biosecurity Officer Ken Massey - who is co-ordinating the Council’s lantana eradication campaign - says varieties of lantana have been grown in northern New Zealand as garden ornamentals since the 1850s and are still present in many gardens.
However, he says the plant is a major problem weed overseas and has the potential for high economic and environmental costs in Northland too.
Mr Massey says the Council aims to remove as many lantana plants as possible from gardens in the lower North in a bid to cut the amount of seed available to be spread by birds.
Birds offer a common and easy mechanism for lantana’s abundant seed to spread to Northland’s reserve areas and roadsides, as well as poorly-grazed open pasture land.
Mr Massey says the NRC campaign will target only ‘Lantana camara’, not the much smaller, sprawling shrub, ‘Lantana montevidensis’. ‘Lantana montevidensis’ is also found in Northland gardens, but is not regarded as an invasive weed.
The Council plans to move its lantana control work into the more heavily-infested Far North District over the next five years.
Mr Massey says where Lantana camara plants are removed from gardens, landowners may also be offered replacement non-weedy garden plants.
“The difference between the two types of lantana is height and flower colour. Lantana camara is an aromatic, prickly woody shrub that can grow to four metres. It has clusters of yellow to pink or orange flowers followed by hard green berries which ripen to blue-black in colour.”
“Lantana montevidensis is a sprawling shrub which is typically less than one metre high and has mauve to purple flowers with yellow centres.”
Lantana camara is poisonous to humans and stock. Young children are very susceptible to any berries, sap, or foliage from poisonous plants.
Mr Massey urges families to have plants identified if they are unsure what is growing in their garden.
People keen to have plants identified and possibly removed should contact Mr Massey or other Council Biosecurity Officers on the Council’s freephone number (0800) 002 004.