Privet

privet

Privet
All privet (Ligustrum species)

Sustained control
Keep privet from affecting nearby land.

Why it is a pest plant

Sustained control
Keep privet from affecting nearby land.

Production threat

Environmental threat

Public threat

Identifying features

Privet is an evergreen shrub or tree with at least four species found in New Zealand. These include tree privet (Ligustrum lucidum), Chinese privet (Ligustrum sinense), Californian privet (Ligustrum ovalifolium) and common privet (Ligustram vulgare). Both tree privet and Chinese privet are tolerant of drought, as well as cold and wet conditions.

Privet’s leaves and berries are poisonous to animals and people. Its pollen and scent is also believed by some to contribute to respiratory disorders such as asthma and hay fever. However, because research shows privet is not a strong allergen for most people, a positive allergy test is needed before the regional council can require a privet tree to be removed on health grounds.

Privet is also an environmental pest, rapidly invading bush margins and waste areas. Tree privet is capable of crowding out canopy trees in native forests, may impede native seedling germination and can eventually dominate an area of forest. Chinese privet can displace shrubs on the margins of native forests.

Privet is widespread and common in the Waikato region.

privet berries

Responsibility for control

Landowners/occupiers in the Waikato must destroy privet on their land if they receive a pest plant notice from Waikato Regional Council (issued when the council receives a positive allergy test for privet from a neighbour), or live in a community initiative area.

The privet causing the problem must be within 50m of the property boundary or within a public amenity area like a park, reserve, playground or walking track.

Privet is also banned from being sold, propagated, distributed or included in commercial displays.

Community initiatives

A ‘total control’ rule for privet applies within the ‘community initiative’ areas of Kāwhia, Tuakau, Whatawhata, Ōtorohanga, Te Kūiti, Pirongia, Kihikihi, Orini, Mangatarata, Te Aroha, Waihi and Paeroa. This means all landowners/occupiers in these areas are required to control all privet on their property irrespective of a valid health-related complaint.

How to control privet

Physical control

Pull out or dig up small plants, being careful to remove the entire root system so it doesn’t regrow.
If you have to cut down a larger plant, you will need to treat the stump with herbicide to stop it from regrowing.
Desirable plant species such as native shrubs and grass should be established where soil has been disturbed. This will suppress the germination of privet and other weeds.
To reduce the impact of privet on asthma or hay fever, regularly trim hedges to prevent flowering.

Herbicide control

Frilling

With a sharp chisel or axe, make a deep cut into the sapwood at regular intervals around the base of the tree. Immediately saturate the cuts with herbicide.

Basal treatment of trunk

This can be done all year round. Apply with a paintbrush or low pressure sprayer using a solid cone nozzle. Liberally treat the full circumference and the basal parts of the shrub or tree trunk 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

This can be done all year round. Cut the tree down, leaving a stump no higher than 5cm above ground level. Immediately paint herbicide over the entire stump surface, including the sides.

Cut and inject

This can be done all year round. Holes are drilled sloping into the sapwood at regular intervals around the tree. Inject herbicide into holes. A drench gun or similar can be used.

Identifying features – Tree Privet

Flower

Small, cream-coloured flowers that are strongly scented and appear from January to March.

Fruit/seed

Dark purple-black berries.
Seeds spread by birds.

Leaf

Glossy leaves that are dark green on top and paler green underneath.

Tree And Chinese Privet

Identifying features – Chinese Privet

Flower

Small white flowers that are strongly scented and appear from September to December.

Fruit/seed

Dark purple-black berries.
Seeds spread by birds.

Leaf

Leaves are small and dull green with wavy edges.

Spray application

This can be done all year round. Spraying is more suitable for smaller or seedling plants but also consider hand pulling. Total coverage of leaf surfaces is required for effective control and is most effective when applied in fine weather during privet’s active growing season, which is 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

Herbicide	Application

Triclopyr plus penetrant	Frilling, cut and inject, cut stump treatment,spray application.
Triclopyr/picloram mix plus penetrant	Frilling, cut and inject, cut stump treatment,spray application.
Metsulfuron plus penetrant	Frilling, cut and inject, cut stump treatment,spray application.
Glyphosate plus penetrant	Frilling, cut and inject, cut stump treatment,spray application.
X-Tree Basal®	Basal treatment of trunk.
Glyphosate gel	Cut stump treatment.
Picloram gel	Cut stump treatment.
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

Management

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.

More information

Advice

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.

Publications

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 5.69, page 163)
Waikato Regional Council pest guide (free)
What makes a pest a pest? A summary of the Waikato Regional Pest Management Plan (free)