Cutting down or digging up weeds and burning the waste plant material are useful, low-tech means of control.
Cutting Japanese knotweed will, over time, weaken the plant and help in its control. You must however take care in handling and disposing of cut plant material. Burning alone may not be sufficient to kill this plant. You should place burnt material on top of a membrane and monitor it for regrowth.
Cutting giant hogweed before the plants flower will help to prevent further seeds being deposited on the ground. This is an effective way of removing these species but it can take many years.
Pulling up Himalayan balsam before the plants flower is the most effective method of control. Cutting plants down before they flower can result in a more bushy plant that produces more flowers.
What you must do
Burning waste materials is a type of waste disposal. You will require an environmental permit (England and Wales) or a waste management licence (Northern Ireland and Scotland) to burn waste in the open.
You may be allowed to burn certain wood or plant wastes without an environmental permit or a waste management licence, provided that:
- the waste is burnt on the land where the material was produced
- in England, Northern Ireland and Wales, you only burn up to 10 tonnes of waste wood or plant matter in a 24 hour period
- in Scotland, you only burn up to 10 tonnes of waste that consists of plant tissue (including untreated wood) in a 24 hour period.
You will usually need to register an exemption with your environmental regulator for this activity.
You must still ensure that your activity does not:
- endanger human health or cause pollution to water, air or soil
- constitute a risk to plants or animals
- cause a nuisance in terms of noise and odour or smoke
- adversely affect the countryside or places of special interest.
If you burn waste in an incinerator or other similar plant, you will need an environmental permit (England and Wales) or a pollution prevention and control (PPC) permit (Northern Ireland and Scotland).
Notify your environmental regulator at least a week before you intend burning plant material.
Notify your local council environmental health officer before you begin burning plant material.
Good practice
Burning plant material should only give rise to white smoke.
Notify the local fire brigade before you begin burning and again when you finish. This will prevent them being called out unnecessarily.
You can leave cut stems to dry out in the sun rather than burning them.
Make sure you place cut Japanese knotweed material on a membrane and not in direct contact with the ground.
Giant hogweed sap remains toxic after the plant has been cut down. Make sure that you do not leave cut stems where they could injure people or livestock.
In this guideline:
