- Last updated:
- 07 Jan 2022
There are many options for managing Invasive plants at your place. Depending on the size of the property, extent of the infestation and location (waterways or inaccessibility) it will determine which option is the most suitable for your property. Not all management options include the use of herbicides, there are many manual or mechanical options that can be utilised: instead, inconjunction with or prior to the use of herbicides.
There are a variety herbicides available for managing invasive plants. When deciding which herbicide to use please do your research and consider toxicity to animals, off-target plants, soils, waterways and yourself. Some herbicides are only effective for specific plants or types of plants so make sure that the one you choose is approved for use on the particular invasive plant you are managing. Please remember that herbicide application without any follow up monitoring or control will have limited success.
If you decide to use herbicides on your property please make sure you:
- use them in accordance with their label
- assess environmental factors (for example presence of native plants and pollinators)
- consider the impact on soil health
- assess surrounding land uses (proximity to waterways or food crops)
- assess weather conditions (wind and rain)
- choose the optimal application time
- consider the use of surfactants to increase the effectiveness of the herbicide
- use the correct Personal Protective Equipment (PPE) and
- use them only as part of an Integrated Weed Management approach.
To minimise the impact of herbicides on foraging insects, including bees
- Use cut and paste method where possible to minimise the need for foliar spraying
- Don’t spray when plants are flowering (Bees and other insects will be collecting pollen and nectar from flowers)
- Don’t spray on windy days when herbicides can drift onto other plants which are flowering and where bees are working
- Spray late in the afternoon when bees have finished foraging for the day.
- Adjust spray nozzle so droplets are bigger and therefore less likely to drift onto other plants
- Check if your neighbour is a bee keeper before spraying invasive plants
- Make sure you follow label instructions – stick to mixing rates on the label
Below is a brief overview of the protection methods that you can utilise on your property to manage and protect against invasive plants.
Bio-control is a method of controlling invasive plants using the plants' natural enemies such as insects. A rigorous testing process is undertaken to ensure that bio-controls are host specific before they are approved and released into the environment. Bio-controls reduce the need to use chemicals and also the cost of invasive plant management. Bio-controls have been released by the Sunshine Coast Council for Salvinia, Madeira vine, Cats claw creeper and Lantana.
Depending on supply and demand you may be able to purchase the following bio-controls from the places below
Bio-control for Cat’s claw creeper and Madeira vine are available from the Mooloolah River Waterwatch and Landcare Inc and Gympie District Landcare
Bio-controls for Salvinia, Water hyacinth and water lettuce from Brisbane City Council
This method is suitable for woody weeds such as shrubs, trees and vines. It involves cutting the plant at the base with secateurs, loppers, a handsaw or chainsaw (depending on the size of the plant) and applying herbicide to the stump within 15 seconds (any longer than 15 seconds will affect results) to ensure that it is absorbed by the plant.
This method is useful for treating most types of invasive plants apart from some succulents and trees. It involves spraying herbicide onto the leaves of the tree which is then absorbed into the plant. Foliar spray can be applied by a back pack sprayer for smaller areas or a quickspray unit for large scale weed control. Sunshine Coast council has back pack kits and quick spray units for hire.
Hand weeding involves pulling out invasive plants manually or with tools. Make sure that the whole roots, tubers, bulbs or corms are removed and any parts of the plant capable of reproducing, are bagged and solarised or disposed of. This method causes minimal disturbance to the soil and to other plants.
Mechanical options include using larger machinery to remove invasive plants. For example tilling the soil or using an aquatic weed harvester to remove invasive plants from the water.
Pasture improvement and revegetation will help to prevent invasive plants from becoming established or re-establishing, create habitat and prevent erosion where invasive plants have been removed.
Tree poppers can be used to remove woody plants such as shrubs, small trees or weedy vines. Tree poppers are set up at the base of the plant and then using some manual pressure the roots are leveraged out of the ground. Council has tree poppers for hire
Some invasive grasses such as Giant Rats tail grass produce significant amounts of seed. The seed heads will need to be cut and bagged before the rest of the plant is dug out.
This method involves removing the outer layer of a 20cm or more section of trunk all the way around the tree or shrub to prevent nutrients from being transported so that the tree or shrub dies. This method is only suitable where falling limbs of the tree will not cause harm to people, animals or structures.
Smothering invasive plants is usually done on a small scale using weed matting, cardboard or newspaper to suppress the growth of plants by preventing them from capturing sunlight. This is useful for groundcovers, grasses and some succulents.
Solarisation uses the suns heat and black plastic cover to control invasive plants and reduce the seed bank in the soil. To solarise invasive plants cover them in thick black plastic and weigh it down on all sides or use pegs to keep the plastic down. The plastic will stop light reaching the plants which will stop them from being able to photosynthesise and will trap heat which will reduce the amount of seeds able to germinate in the soil. The process takes around 2 to 4 months depending on the weather. Factors such as rain and temperature will affect the success of solarisation. Solarisation is not usually effective for deep rooted plants as the soil temperature is usually only hot enough in the top couple of centimetres.
The splatter gun application method shoots a stream of herbicide with precision across a distance of around 8 to 10 metres. It is useful for forested or steep terrain where access limited and for the treatment of invasive shrubs like lantana. Council has splatter guns for hire.
This method is useful for weedy vines and involves scraping off a section of the outer bark and applying herbicide within 15 seconds (any longer than 15 seconds will affect results). Wrapping plastic around the area where the herbicide has been applied can assist with the absorption of the chemical by the plant. The herbicide is transported throughout the plants vascular system killing it entirely. This method is useful for Madeira vine as it can easily regrow from stem fragments and therefore it is important to kill the whole plant.
Wick wiping involves the application of herbicide by either a hand held or a rotating wick on a trailer, onto undesirable plants. The use of a trailer wick wiper is only appropriate for faster growing pasture weeds where a distance is able to be achieved between the invasive plants and desirable pasture species so that the wick only touches the invasive plants. A hand held wick wiper is useful for a variety of invasive plants including pasture weeds, ground covers and small shrubs. A hand held wick wiper allows a concentrated amount of herbicide to be wiped onto a plant. This technique is useful for pasture weeds. Council has both trailer and hand held wick wipers available for hire.