Bamboo has become very popular in recent years, especially in urban areas. But more and more disputes are now caused by this plant. So is bamboo invasive?
Bamboo plants – As home improvement advice it might be an unusual one, but all homeowners need to be wary about what is becoming the Great British bamboo plant invasion.
Indeed, gardeners are now being urged not to grow bamboo because it threatens your home’s foundations and also your neighbour’s land.
Worryingly, the plants cannot be killed-off with herbicides and will need extensive work to destroy the roots.
And even more of a worry is that experts are now predicting the issues will become more of a problem than we have seen with Japanese knotweed since they have similar properties and can push through cavity walls, drains and brickwork and also exploit weaknesses and cracks in concrete.
To underline this point, there has been a recent court case involving a homeowner in Chandler’s Ford, Hampshire, who discovered bamboo was growing between the skirting board and his living room wall. The plant had encroached into his home from next door’s garden by exploiting a weakness in his property’s foundations.
How bamboo plants grow
To understand why bamboo is invasive and can cause problems, we have to know how they grow. Having an understanding of the plants root system and method of spreading will also help to prevent them from causing damage.
Bamboo is a type of grass and has a shallow root system, penetrating no deeper than about 1m (3 feet). Like grass, the bamboo shoots, called canes or culms, will grow out of the ground in spring. Bamboo grows for 60 days after the emergence of the canes.
Unlike grass, they are thicker, sturdier and can grow up to 5m (16 feet) here in the UK, depending on the species.
Once the growing period is over, this is it, the cane has reached its final height. But it will use the energy it produces to grow more culms the following year. So bamboo is a colony plant.
The following year, the canes can grow higher and thicker, even though they only grow for 60 days. The way bamboo spreads is by sending out rhizomes or runners. Similar to strawberry plants, but bamboo runners are below the surface.
There are two different types of bamboo that send them out in different ways.
- ‘Running’ – these have rhizomes that spread out or ‘run’ far away from the mother plant
- ‘Clumping’ – the runners on this type stay close to the original plant
Running bamboo
This type of bamboo sends out its rhizomes far away before new shoots are sent out. So new bamboo canes might appear at the other end of your garden or even in your neighbour’s garden.
While the roots of bamboo are quite thin and fibrous, the rhizomes are strong and woody. They are able to grow under walls, patios and garden paths. So it’s easy to see how they cross property boundaries.
There were reports that the runners even managed to get into people’s houses through cracks or weak mortar and caused damage to property foundations. The shoots that emerge from the rhizomes are so strong that they can break through tarmac, patio and conservatory floors.
Because of the way they spread, running bamboo can grow shoots far away in the distance and cause issues, for example, with neighbours. It also spreads quicker and homeowners might not even be aware of the fact.
Clumping bamboo
The other type of bamboo only produces short runners and new shoots will appear in a clump around the original plant. Hence, why these varieties are called clumping bamboo.
These types of bamboo spread much slower than the running varieties, and they don’t spread as far and wide. However, this doesn’t mean that the rhizomes and shoots can’t cause damage.
All bamboo is invasive
Bamboo has grown in popularity, particularly in urban areas as it is easy to grow and helps create privacy in those properties that are overlooked by neighbours.
But is all bamboo invasive? Strictly speaking, there are no types of non-invasive bamboo plant. All varieties of bamboo can be highly invasive and will spread out of control if they are not cultivated and checked. As a colonising plant, its aim is to spread as far and wide as possible.
One specialist in removing invasive species, Environet UK, warns that bamboo plants can become a huge problem if left unchecked, similar to Japanese knotweed.
Of course, as you might have guessed, running bamboo is far more invasive than the clumping varieties. They are more difficult to prevent from spreading and they will spread quicker.
Does this mean you shouldn’t plant bamboo in your garden? Well, that’s up to you. But if you do, you should be prepared to keep it in check.
The Royal Horticultural Society (RHS) recommends that people stick to clumping bamboo varieties, as these are easier to control and, therefore, are less likely to become invasive.
These types of plant include: Bambusa, Chusquea, Fargesia, Shibataea and Thamnocalamus.
Running bamboo varieties, such as Arundinaria, Bashania, Clavinodum, Phyllostachys and Pleioblastus, are better avoided as they can quickly turn invasive and cause problems.
Stopping bamboo from spreading
There are ways to prevent bamboo plants from spreading, whether this is ones in your garden or from your neighbour. As we know, they spread through sending out rhizomes, so by stopping them, you can stop the spread of the plant.
Your neighbour’s bamboo
If your neighbour has bamboo in their garden, and you have noticed shoots come up in yours, you can dig a trench along the boundary. It has to be at least 1m (3ft) deep. If you come across any bamboo runners, cut them off and remove them.
Fill in the trench with solid materials, such as paving slabs or corrugated iron sheets. These will keep any further runners from your neighbour’s garden at bay.
Once this is done, you need to keep an eye on your garden for any bamboo shoots coming up. This will happen in spring. If you spot any, cut off the canes. This will starve the plant, stopping it from sending up more shoots.
We can’t stress enough how important it is to be vigilant. For example, the Guardian covered a story of a Hampshire homeowner spending around £100k for removal. The culprit? A neighbour’s bamboo plant had been spreading its rhizomes underneath their home for the past years.
Bamboo in your garden
Any bamboo you have in your own garden needs the runner’s pruned regularly to prevent it from spreading. This means digging down and cutting off any rhizomes you find. If you want to spare yourself this job every year, you can create a barrier around the plant, by using the same trench technique as described above.
To prevent the stems from reaching over, let the barrier stick out above the ground by at least 30cm (1ft). Another way to contain bamboo plants is to grow them in containers with root restrictors.
This will only work if you are planting them new; it will be difficult to transplant existing plants into pots. As we have said before, if you want to plant bamboo in your garden, opt for clumping varieties, as they are easier to contain.
If you have clumping bamboo in your garden, you need to remove sections from the edge of the plant. This could be a difficult job, depending on how big the plant is or how hard your soil is.
What’s important is that you cut off the rhizomes of the sections you remove, so they are no longer connected to the mother plant and remove them. This will prevent clumping bamboo from spreading and becoming invasive and cause issues.
As you can see, growing bamboo isn’t for the idle. It involves a lot of hard work to keep it in check to ensure it won’t cause problems.
Bamboo and the law in the UK
Under the Wildlife and Countryside Act 1981, the planting of invasive species is forbidden. But unlike Japanese knotweed, which is on the list, bamboo is not classed as an invasive species in the act.
This means that you are free to plant bamboo plants in your garden if you so wish. However, court cases where homeowners sue their neighbours because their bamboo has spread to their garden are becoming increasingly common.
The law used is the same as that for Japanese knotweed: common law private nuisance and the offending neighbour can seek compensation for things like loss of enjoyment, property damage and costs of removal.
Given the growing problem of bamboo invasions, neighbourly disputes and court cases, there is a chance that bamboo will join Japanese knotweed on the list of banned plants. There is also a chance that mortgage lenders will add lending restrictions if bamboo is present on the property.
This is already the case with Japanese knotweed, so it wouldn’t be surprising if bamboo follows.
Buying a house with bamboo
Given the potential issues that the presence of bamboo can cause, you might wonder if you should be buying a house that has bamboo plants in the garden.
As long as you make sure you know all the details, it shouldn’t put you off. After all, losing your dream house because the owner planted bamboo seems a bit daft. Here is what you should find out:
- What type of bamboo is it – clumping or running?
- Are there any constraints in place – is the bamboo planted in a pot, or has a trench been dug around it?
- Has there been any issue with the bamboo invading neighbour’s land?
If the bamboo is of the clumping type, it’s less likely to cause issues and easier to contain. However, if it’s the running type, you want to make sure that it has been kept in check regularly or its rhizomes contained.
In the case this hasn’t happened, you should look into costs to remove the plant, which might not be cheap, depending on how old the plant is and how long it has been allowed to spread. You could try to negotiate the price, given that you will have to spend a good amount of money to remove the plant.
Prices for a specialist company to remove the bamboo and solve the problem once and for all could range from £1,000 + VAT to up to £7,000 + VAT depending on the scale of the problem.
A gardener or landscaper might charge much less, between £100 and £500. However, specialist companies, such as Environet UK, will provide you with a guarantee of at least one year. During this time they will check if any regrowth is appearing and treat it.
In the case of a Northamptonshire retired homeowner, the bamboo he planted a decade earlier cost more than £6,000 in damages to remove.
To establish how big the problem might be, if there is a problem at all, and how much it would cost you to rectify it, arrange for a survey. The surveyor can assess the potential risk and provide recommendations about remedies and costs involved.
Get a survey to check for invasive species:
Selling a house with bamboo
Of course, it’s not just a potential issue when you are buying a house, but also when you are selling one. You might wonder if you have to declare that you have bamboo in the garden.
Unlike with Japanese knotweed, you aren’t under any legal obligation to declare that you have bamboo in your garden. That’s because legally it’s not classed as an invasive species, at least not yet.
However, if a buyer asks you if there are any bamboo plants in your garden, then you have to be honest. Lying could lead to legal action, if the buyer finds out later, and it has spread and causes damage or is a nuisance to the neighbours.
The presence of bamboo can devalue a property because of the high costs of removal and potential risk to the building.
According to Environet UK, Japanese knotweed could devalue your property by up to 10%. And while bamboo might not yet be at the same level, it might lead potential buyers to try and negotiate on the price.
So while having bamboo in the garden won’t be a dealbreaker for most buyers, some might try to get a lower price because of it, if the plant hasn’t been contained appropriately.
Conclusion – Is bamboo invasive?
All bamboo is invasive if left to grow unchecked. However, legally bamboo is not yet classed as an invasive species and can be planted freely.
However, it’s worth ensuring that the plant can’t spread, as it can cause damage to your garden, property and potentially issues with your neighbour. Experts recommend opting for a clumping variety, which is easier to contain as it doesn’t spread as widely.
Regular maintenance is required to keep a bamboo plant in check and stop it from becoming invasive.
Due to the potential damage this popular plant can cause and the high costs of removing it, you should know the full picture before buying a house that has bamboo in the garden. When selling a house containing it, be prepared for questions and potential price negotiations.
More information
If you really want to have bamboo plants in your garden, then this RHS advice will help.
