Most varieties of bamboo tend to expand because of their trailing rhizomes. If they are happy in your garden, there is a real risk of them becoming overgrown. Let's see how to control them.
The roots of bamboo
Most bamboos, with the exception of certain Fargesias, have rhizomatous and tracing roots, i.e. underground organs capable of containing a reserve of nutrients. These organs move horizontally and serve as a natural multiplication of the plant which then forms vast clumps. If left unchecked, the expansion can be spectacular, especially if your garden conditions are conducive to their development.
Different methods of controlling bamboo
The spread of bamboo is not inevitable! There are many solutions to limit its progression:
The trench
Delimit the area dedicated to your bamboo by digging a trench about 40 cm deep and 10 cm wide around its periphery. You will then just have to watch for the appearance of new shoots and to give a clear spade stroke in the trench to eliminate them. If you prefer, you can also proceed with the help of a lopper which will quickly cut the unwanted rhizomes.
The anti-rhizome barrier
The anti-rhizome barrier made of thick polypropylene, almost rigid, allows to stop the progression of bamboos in a very efficient way, but for that, it must be positioned in the rules of Art! Place it at an angle of 15° to the bamboo clump. It must be installed at the plantation at a distance of 50 cm to 1 m. The depth of the trench where it will be placed should be slightly less than the height of the anti-rhizome barrier so that it protrudes a few centimeters from the ground to prevent the roots from jumping over it.
To hide it, you can install large round pebbles that will emphasize the 'zen' side of the bamboos or cover it with a slate mulch or colored RCW.
The Masonry
The most courageous will build physical barriers with cinder blocks or bricks. Be careful to cement the whole thing so that there are no gaps where rhizomes can infiltrate. Here again, leave 2 cm above your low wall so that the roots do not jump over it happily.
The mower
Sometimes the lawn is next to a bamboo planting that stops at the edge of the lawn. Some people even plant a clump of ornamental bamboo such as the famous Phyllostachys nigra in the middle of it. If you regularly mow the lawn, the aerial shoots will be removed as they appear.
