Weed projects and focus areas

Aquatic weeds are known to displace natural vegetation, destroy aquatic life and reduce habitat available to fish. Aquatic weed management remains a focus for us with a variety of high priority weeds such as alligator weed, amazonian frogbit and senegal tea plant infestations in the Karuah and Manning Catchments being monitored and managed where required under integrated weed management programs. 

Myall Lakes Catchment

Aquatic weeds were monitored and treated along 46 km of stream bank this year. The ongoing monitoring program has revealed significant reductions in densities and occurrences of the target weed parrots feather.

A 1.5 ha area of Alligator Weed received multiple treatments at the obsolete landfill area contained within Tea Gardens Waste Management Centre. This infestation is currently being managed under an intensive, ongoing, integrated weed management program. In Tea Gardens, 1.5 ha of salvinia-infested water bodies were treated. An integrated management program for longleaf willow primrose in drainage areas of Tea Gardens is ongoing.

Karuah and The Branch Estuary

Water hyacinth is an aquatic weed impacting water bodies on numerous private properties in many localities throughout the floodplains of the Karuah Catchment, including Nooroo, Stroud Road, Washpool, Stroud, Booral and Allworth.

Along with private land managers, we have been undertaking controls to manage this weed in various areas for many years, however a problem such as this requires an ongoing large scale coordinated approach to truly be effective. Due to many complexities the effectiveness of biological controls are limited.

We intend to form a partnership with affected land holders and seek external funding to implement a long term control strategy. Water hyacinth may rapidly take over an entire waterway and its large reproductive capacity can cause annual re-infestation thus making ongoing control necessary. There are new off label permits available for the use of certain herbicides to effectively treat Water Hyacinth on water bodies. Land managers should contact us for management advice.

Wallis Lake 

Amazon Frogbit is a floating freshwater plant from Central and South America, introduced into Australia as a decoration for fish ponds, aquariums and water features. It can rapidly invade and smother waterways and is a serious biosecurity threat.  See the separate section on this page below for more information.

The discovery of the aquatic weed near Forster was the first time Amazon Frogbit has been found in a natural area in NSW and triggered an emergency response to control the spread of the weed. We are working closely with Hunter Local Land Services, the National Parks and Wildlife Service and the NSW Department of Primary Industries (DPI), implementing management activities including treatments of the infestation ongoing monitoring and private property inspections. This project is ongoing and we are confident that a target of eradication is feasible.

Senegal tea plant, a native of the American continents, can float on still or very slow moving fresh water or grow as a bush on wet, marshy soils. It has been recorded at localised sites in most states. It is mainly spread by careless disposal of aquarium plants or deliberate cultivation for sale.

Because Senegal tea plant grows very quickly, it can rapidly cover water bodies with a floating mat, excluding other plants and animals that rely on them.

Approximately 80 km of rivers in the Manning catchment have been identified as infested with Senegal tea plant, from the lower reaches of the Barrington and Gloucester Rivers to Abbotts Falls on the Manning River, just south of Wingham.

Although Senegal tea plant has reached the known tidal limits of Abbotts Falls, there is a concern that future flood events could spread the infestation further downstream in the Manning River, as little is known about the plants ability to survive in brackish water. Should the Senegal tea plant infestation go unchecked, serious economic and environmental damage could occur.

Because of the potentially serious impact of Senegal tea plant on the environment, water resources, primary industries, tourism and recreation, we’re committed to control programs for this weed.

Current Operation: Senegal Tea Plant

We are carrying out herbicide spraying from November 2024 through to end of January 2025. Find out further information on this program.

We’re working with partners on an exciting new trial to sterilise weed trees that may allow us to protect Australian bush habitats while keeping our significant historic trees in towns. Many grand old trees in the streets and parks of our towns, including popular introduced species like camphor laurels and African olives, were planted over a hundred years ago, before anyone was aware of the damage exotic species would do to the beautiful and unique Australian bushland.

But they've grown on us - literally! Generations of family photos and community events feature these trees that stand proudly today. Unfortunately, each year, they send their seeds far and wide, crowding out the natives. This has devastating effects on native wildlife as natural food sources are squeezed.

MidCoast Council is leading a ground breaking trial project in Australia and working with local neighbouring Councils, the Hunter Local Land Services and NSW Department of Primary Industries, that involves 'sterilising' the old trees so they no longer produce seeds.

The $150,000 project is funded by the Australian Government, Department of Agriculture and Water Resources through their 'Control Tools and Technologies for Established Pest Animals and Weeds Program'. Products that are currently registered for use in the USA are being trialled in Australian conditions, in various locations, potentially leading to registration for commercial use in Australia.

The project involves trialling the application of certain chemicals to trees, via foliar spraying and injection. Treatments are undertaken at flowering time of the individual species being targeted to cause flower drop, arresting the production of seeds.  If the trial is successful, we can retain many trees that may be viewed as significant.

Running or rhizomatous bamboo is a plant that MidCoast Council cannot enforce the removal or containment of. It is not a "priority" weed species either locally or under the Hunter Regional Strategic Weed Management Plan 2017 - 2022. All bamboo is generally recognised as a nuisance plant often between neighbours.

If you want to have running bamboo on your property, to be considered a good neighbour, it should be contained either in pots or with an “escape proof” root barrier and maintained.

If you are having issues with Bamboo coming across your boundary from a neighbours’ place, talk to them first, as they may be having the same issues you are and are not sure how to tackle it. Any interactions you have with them regarding the bamboo issue should be documented or diarised in case of any future action taken. If you cannot get any action, contact the Community Justice Centre to assist with mediation on the matter. If mediation fails and the Bamboo is causing structural issues with your dwelling or services, action may be taken under the Trees (Disputes Between Neighbours) Act. For the purpose of this Act, the regulations deem Bamboo to be a tree.

General information about root barriers

• Bamboo root barriers are generally available from nurseries that specialise in Bamboo. Other nurseries, hardware stores and arboriculture suppliers should be encouraged to make these more available.
• Before installing any barrier, all existing Bamboo between proposed barrier and property boundary must first be completely eradicated either by physical removal or poisoning (see control techniques below).
• Consider recommending the use of other plants that can provide similar functions but do not have the same invasive habit as Bamboo. Some alternative non-invasive clumping Bamboo species include Bambusa multiplexa, many cultivars exist from 1m to 10m high, and Bambusa balcooa which grows from 15-30m tall.
• The root barriers recommended below should, as much as possible, be monitored for their effectiveness, and where necessary these specifications will be reviewed as new information is received.

Location of the root barrier

• Barrier may be installed at a distance of 1,000mm from the property boundary/ fence line or retaining wall of the property with the bamboo. This will facilitate adequate and regular inspections of the rhizome barrier and allow for any necessary maintenance as required, and without having to enter adjoining property. If this barrier is being installed on a property adjacent to an infestation to prevent further spread, the barrier should be installed as close as possible to the dividing fence.
• During barrier installation, care should be taken to avoid damage to underground pipes and cables. Contact Dial Before You Dig on 1100 or visit their website
• Barrier should divert around large trees to avoid root damage during installation.

Root barrier fencing

 Construction

• Barrier fencing should be made from a material which will not rust, break or shatter in the long term e.g.
• Reclaimed or recycled conveyor belt rubber.
• Polycarbonate roofing with four corrugations overlapping at the seams sealed with a silicone adhesive.
• High density polystyrene or polyethylene plastic, 40 mm or heavier, glued at junctions, or clamped with stainless-steel clamps.
• Galvanised iron is not suitable because it will rust over time.
• No barrier is suitable in rocky ground.
• Where the soil is poor and the existing rhizome descends no more than 150mm, construct a barrier 600mm deep.
• Where the soil is free draining or kept moist, or where the rhizome descends more than 150mm, the barrier should descend to at least 1000mm depth (or when in doubt, up to 1200mm).
• Barrier should protrude 100mm above the ground to hinder rhizomes growing over top.
• For added benefit, the barrier should be installed sloping away at the top and towards the bamboo grove at the bottom, so that when the rhizomes hit the barrier they will bend upwards rather than down (a barrier does not stop a running rhizome, it only deflects it).
• Where extra support is required, the barrier should be securely tied to star pickets installed into the ground to at least 200mm below the barrier, and at maximum intervals of 1.5m.
• To ensure adequate confinement where the ground level changes abruptly:
• The full depth of the rhizome barrier should project from the bank
• At the foot of the bank, the barrier should return at least 300mm back into the area to be confined.
• There must be no gaps in the barrier otherwise it will be ineffective.
• The barrier must extend the whole length of the bamboo infestation.
• If the barrier is not continuous, it should join with an existing structure that will prevent the bamboo spreading eg masonry wall with deep footing, and must be material that is a least as deep as the rhizome barrier and not prone to degrading eg concrete.
• Where the rhizome barrier ends at a wall it should be returned around the corner and along the wall, at least for 350mm so that the rhizome is forced to grow back into the infestation itself. The barrier should be secured hard up against the wall (using adhesives and hardware such as masonry nails or Dynabolts^TM) so that the rhizome cannot grow outside the barrier.
• Retaining walls should be installed where steep banks cannot support the barrier in the long term.

Maintenance

 The top of the barrier should be checked every 6 months to:

• Cut off and remove any rhizomes that are growing over top.
• Remove any build-up of leaves and debris. Bamboo sheds many leaves forming a dense leaf mulch layer on the ground that makes it more difficult to properly inspect the barrier for rhizomes growing over the top or underneath.
• Repair any defects or damage to the barrier, including re-installing any loose star pickets.

Use of reinforced concrete

• Dig trench 1200mm deep and 150mm wide with small backhoe or other trench digging machine.
• Fill trench with reinforced concrete.

Escape proof planters made from fibre reinforced cement

• Different sized cylindrical planters are available according to desired height of plant. The minimum diameter is 450 mm (smaller than 450mm may force the rhizome deeper than 1m in the ground).
• Depth of the planter must be at least 1000mm underground.
• Set top of planter at least 50mm above ground.
• Keep soil level 50 - 75mm below the top of the planter to expose any rhizome that jumps the top of the planter.
• Inspect and cut off all rhizomes that grow over the side of the planter on a regular basis.

Bamboo plants contained in pots

• Bamboo may be grown in a pot if it is placed on a hard surface (eg non-cracking concrete), off the ground, or on a large saucer underneath the pot, to prevent spread of rhizomes.
• Water
• A water-filled pond, stream or ditch can also effectively block the spread of bamboo, since rhizomes and roots cannot tolerate extended periods of saturation.
• Water need only be present for one season a year.
• This option should only be used if pond, stream or ditch already exists.

Mechanical control

Carefully dig the base of the plant, rhizome (underground stem) and roots out of the ground and dispose of at the tip. Fill the hole and mulch the area to discourage any regrowth from any remaining stem fragments. If regrowth occurs, dig up the stem and rhizome and dispose of in your bin.

Chemical control

If you choose to kill this weed by chemical means you should use a Glyphosate based herbicide (applied in accordance with APVMA Permit number PER9907).

For best results, cut bamboo stems off just above ground level then immediately paint the stump with a glyphosate mixture at a ratio of 1 part glyphosate to 1.5 parts water). This must be done one stem at a time. Get tips on removing bamboo.

Smaller plants can be sprayed with a mixture of 1 part glyphosate to 50 parts water (applied in accordance with APVMA Permit number PER9907). Choose a day when it is not too hot, is not windy and rain is not forecasted for at least 24 hours. Caution should be taken to ensure that overspray onto desirable plants and neighbouring properties does not occur.  If foliar spray has been used, wait until the plant has completely died. Remaining dead stems should be cut off at ground level and mulched over to prevent any reinfestation.

Larger clumps can be sprayed under a separate APVMA off label permit, with a very effective herbicide, however as it is not available over the counter to the general public work must be done by a qualified contractor with the appropriate chemical training.  Contractors can contact your Council Weeds Officer for details of the chemical and conditions of use on the 02 7955 7777 or via email to [email protected]