*22 July 2011*

The Ministry of Agriculture and Forestry (MAF) and the Waikato
Regional Council are calling on Hamilton residents to help them locate
any further infestations of an invasive weed pest recently located on
two adjacent residential properties.

The vine Chinese knotweed (Persicania chinensis) is a vigorous
climber with the ability to smother native plants, forest areas and
horticulture operations. The plant puts out a deep and wide network of
roots, enabling it to spread rapidly. It is also suited to a range of
environmental conditions.

The weed was discovered in two home gardens in the Chartwell area of
Hamilton by a scientist who reported it to council biosecurity officer
Darion Embling.

“We have moved rapidly to contain and get rid of this pest. All
plants found at the two addresses have been treated with a herbicide
and further treatments will be applied to ensure this robust plant is
fully destroyed,” Mr Embling says.

The council is working closely with MAF in the careful management of
the infestation. MAF spokesperson David Yard says key to full
eradication of this aggressive plant from New Zealand is ensuring that
all outbreaks of it are found and treated.

“We’re talking to the property owners concerned to gain some
picture of how the weed may have got into their gardens and also to
attempt to trace any other locations that the plant may be present.

“When we know where a pest like this is, we can do something about
it. This plant is a known pest elsewhere in the Pacific and we want to
stop it spreading any further here,” Mr Yard says.

“We urge people to call us if they think they have Chinese knotweed
on their property. We recommend that they do not try to control it
themselves. This plant is likely to be spread through fragments
breaking off and re-sprouting into new plants, or on contaminated
garden tools, so people treating it themselves could accidentally
spread it further.”

Chinese knotweed plants grow to 70 cm to 1 metre tall in open ground,
but are aggressive climbers that smother trees and other structures.
Stems are pinkish in colour and leaves are generally soft textured,
serrated edged and 4-16cm long. Chinese knotweed flowers in autumn.
Its flowers are cream/pink and grow in clusters at the end of leafed
stems.

*To report suspected sightings contact MAF on 0800 80 99 66.*

*Full information about Chinese knotweed is at:
http://www.biosecurity.govt.nz/pests/chinese-knotweed

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