How to Control Bamboo
Bamboo can be a wonderful feature in any garden, but it can also be a troublemaker.
The term Bamboo is a common name used to describe a wide range of plants that belong in the grass family. There are about 10 genera that contain members of the Bamboo group. Bamboos are evergreen i.e. they do not drop all of their leaves at once, they are grown for their attractive foliage and their canes (also referred to as culms) which are sometimes unusual colours such as black or blue.
Bamboo grow and spread by means of modified underground stems called rhizomes. The rhizomes are also able to store food for the plant. Bamboo plants usually grow without producing flowers for many years or even decades. When they do flower, the process of flowering weakens the bamboo plant to such an extent that they may need replacing because their growth and vigour will never be the same again post flowering.
Many bamboo species come from tropical regions of the world but some come from hardy habitats which make them suitable for growing in UK gardens. There are many different bamboo varieties to choose from and they grow to a range of heights. Some only grow 50cm tall whilst others can grow up to 7 metres tall.
Many gardeners fall out of love with Bamboo because some species and cultivars can be extremely invasive and can become a problem in the garden. The best time to keep Bamboo under control is when you plant it, but this might not always come to mind if you are unaware of just how much trouble the plant might cause a few years down the road.
Controlling Bamboo's Spread
Whether it is at planting time or at a later date, a physical barrier is the best way to keep a bamboo plant under control. The first thing to do is to source the right sort of material for the barrier.
If it is at planting time, the easiest thing to do is to put the plant into a large pot and then sink it into the ground making sure the pot has good drainage holes before you do so.
If it is long time since planting, you will need to find a suitable material to act as a barrier around the plant. The ideal material would be a strong, plastic that is also flexible enough to form a circle around the plant.
Dig a deep trench all around the bamboo plant, the trench should be at least as deep as the rootball of the bamboo plant. Then insert the flexible plastic sheet in the trench around the plant so that it completely encircles it. Seal the piece of plastic at both ends or at least make sure that it overlaps. Ideally the plastic will protrude slightly above the soil surface which will act as an obstacle to any shoots that might try and creep along the surface of the soil. Once you have the barrier in place you can backfill the soil, firming with your heels as you go.
War of Attrition
If you can’t get hold of a suitable barrier material or expense is an issue then you also have the option of simply cutting around the bamboo plant every six months or so with a sharp spade to a spade’s depth creating a perimeter slit trench. This will severe the roots that will always be trying to radiate out from the parent plant. There will be no permanent barrier with this method but you will have to remember to do it every six months to keep the plant in check or you will be back to square one.
But often people leave Bamboo plants to romp away for many years before they realise they have a problem and new undesirable shoots start popping up in neighbouring beds, borders, and driveways. Nearby paving slabs and driveways are no deterrent for the most invasive bamboo varieties. They will happily send up new shoots between individual paving slabs from their underground stems.
Once you have contained the parent plant as discussed previously, you have made a good start.
The trouble is every time the underground stems send up a new shoot, the new shoot develops it’s own root system and therefore becomes independent of the parent plant. It can be a real battle lasting years to completely eradicate unwanted bamboo from your garden. Your options are to either dig out the unwanted bamboo shoots; but you will have to do this time and time again to make sure you are rid of them. Or you can try spraying them with a weedkiller that will kill the whole plant including the roots using a product such as Roundup.
Where you have bamboo shoots coming up through a lawn, you will not be able to use Roundup because it kills all plant material it touches, which would include your lawn grass in such a scenario.
Don't let me put you off Bamboo, it's a fabulous plant to have in the garden but you do need to make sure it know's who's boss from day one.
This article is dedicated to Valerie, to whom we are eternally grateful for her help and support.