Japanese Knotweed is a garden monster, but gardeners may be unaware of the potential consequences of planting bamboo into the ground. While most of us are aware of the perils of finding Japanese Knotweed in our gardens, garden centres around the UK are happily promoting other invasive plants to gardeners who may be unaware of the potential consequences of planting them into the ground.
In the case of these plants, no statutory control is in place, such as those applying to plants including Japanese Knotweed that are listed in Schedule 9 of the Wildlife and Countryside Act (England and Wales).
Gardeners may be unaware of some of the plants that were added to the schedule in October 2022, including varieties of cotoneaster, Virginia creeper and montbretia (crocosmia), all of which are commonly seen in our gardens but which have also established in the wild.
It is an offence to plant or allow the plants listed as a Schedule 9 species to spread into the wild as they will quickly take over habitats. It is not illegal to plant them on your own property but it is an offence to allow it to spread onto other properties.
Bamboo
The innocuous bamboo has not yet been added to the list.
Bamboo is a type of grass and many of the nearly 1,000 different bamboo species readily spread in the garden. This can give cause for disputes with neighbouring properties should the plant invade property boundaries. Property owners in the UK have a legal duty to prevent their plants from causing a nuisance to neighbouring properties. This includes controlling the spread of any invasive plants, including bamboo.
Just last year it was reported that bamboo caused over £100,000 of damage to a Hampshire property that had been invaded over several years after spreading from the neighbour’s property. The bamboo was growing under the floors and sprouted dense new shoots from inside walls. The remedial work took several months to complete and involved the excavation of the entire ground floor of the home, including the living room, study, hall, kitchen and wall cavities.
How does bamboo spread?
Bamboo spreads through runners that run laterally and, in many cases, very quickly. If not controlled, bamboo can grow into dense clumps several metres wide. The strong shoots (culms) can penetrate pathways, driveways, and even concrete walls and floors – yet awareness of these properties is less widespread.
Out of control bamboo can be difficult to remove, as it develops a dense and widespread rhizome network beneath the soil that can retain viability when the top growth is removed. Physical removal of bamboo may even require mechanical excavation, and the brittle rhizomes must all be removed to ensure the problem isn’t simply spread about. Once removed, the risk of re-growth can be controlled by treatment with a herbicide, but this will need to be applied over several years for a full effect.
If you do plant bamboo in your garden, you should plant it in a container or strong pot rather than directly into the ground. Even if you plant a guaranteed less invasive species, take care to install a physical barrier at least 600mm deep and ensure it protrudes above ground level to prevent the rhizomes from growing over it. Metal or heavy duty plastic sheeting can be used, but these should be regularly checked to ensure it has not been breached or damaged.