Retrofitting the root barrier - tips and instructions

Some plants would spread uncontrolled without a root barrier. We will show you how you can also install them later.

When planting in the garden, there are a few things to consider. Every plant needs a specific location. This should be in the sun, partial shade or shade. In addition, plants need enough space to develop well. The roots must be able to spread in the soil in order to provide the plant with sufficient water and nutrients. This is not a problem with most plants. But some representatives like to overdo it with their joy in growing and the roots displace plant neighbors and spread throughout the garden. If you do not consider this, you may soon lose the joy of the flora. You can stop the growth of vigorous plants by using root locks. If you have failed to do this during planting, you can breathe a sigh of relief because root locks can also be added later. In the following, we explain how to proceed in detail.

Why do you need a root barrier?

Some plants form underground roots, so-called rhizomes. However, if you want to offer your plants a lot of space, you don't necessarily have to do anything. However, such an expansion is usually not welcomed. After all, there are other plants in the bed and the neighbor should not be flooded with a sea of ​​plants.

Immediately after planting, the world is still in order. Only a few years later did the plants form so many runners that they now take up almost the entire garden. Often, not only are the other plants displaced, but also pond foils are perforated, slab panels are lifted out or even cables and parts of the building are attacked. Root locks can prevent this. So don't be afraid to install root locks later. Although it will cost a lot of effort, it will prevent you from overgrowing your garden in the future and possibly causing even greater damage.

Which plants should get a root barrier?

There are some plants that quickly take over the garden without root lock. In this context, the bamboo is usually mentioned first. Bamboo not only grows particularly quickly, it also has aggressive roots, which develop unexpected strengths and do not stop at stone slabs or ceramics. Raspberries have also formed numerous runners within a few years. You will then have a rich harvest, but you will also find the shrubs everywhere in your garden. You experience the same with mint. Once planted as a small spice jar, the mint quickly becomes an impressive shrub and also forms numerous runners. Ivy, vinegar tree or sea buckthorn should also be rooted. Even the rather inconspicuous lily of the valley can reproduce uncontrollably.

Tip: Root barriers should be used when planting, if possible.

Pay attention to high-quality material and correct installation

The subsequent installation of a root barrier can be necessary if you have simply forgotten to do this when planting. Maybe they did not know it or were not given enough advice when buying plants. There may be various reasons. Perhaps they have also installed a root barrier and have to find out that it did not meet their requirements. This can also have various reasons. For example, if root locks are not closed properly, the roots will find their way through the smallest gaps. Perhaps you have also tried to work with pond liner instead of a special liner made of resistant plastic. Especially when it comes to bamboo, no compromises should be made. The roots are particularly aggressive and seem to easily penetrate pond liner or roofing felt.

In the video you can see how difficult it is to get rid of sprawled bamboo growth. In this case, root locks were included in the planting, but apparently wrong.

Add a root barrier to bamboo

With bamboo it is also possible to retrofit a root barrier. However, it will take some effort. The rhizomes are not only found several meters from the mother plant in the entire garden, they are also particularly robust and hard and therefore not easy to remove. It is important to completely remove all roots that have spread out of the ground. It will not be enough just to pierce the rhizomes. A spade is usually not enough and the hobby gardener will not be able to avoid using an excavator.

In the case of bamboo, the root barrier must be installed generously, because the bamboo plant needs enough space and does not want to be restricted when it grows.

Tip: Do not dispose of the removed rhizomes on the compost heap, because the bamboo would continue to grow there unhindered.

Subsequent installation of root barrier step by step

  • Remove roots
  • Dig the trench
  • Insert root barrier
  • Close root barrier
  • Fill up earth
  • Press on earth
  • Water the plant

Remove root system

Before you install the actual root barrier, the rampant root system must be removed. You may not be able to find all the roots, but care should be taken. It will take some digging work to get the rhizomes out of the ground.

Dig out the trench and insert the root barrier

Then a trench is dug around the plant in question. This should have the appropriate dimensions for the plant and, for example, be about 80 centimeters in diameter for bamboo. Remove the plant from the soil and check the roots. Then it is easier to estimate which space you should give the plant. The trench must also go deep. Allow around 70 centimeters for this. Only then is the root barrier inserted. This should not be flush with the ground, but should protrude five to ten centimeters above it, so that the root runners cannot find their way above ground.

It is important that the root barrier is tight. Special rails are available for this, which are screwed to the root lock. You can also weld the special film so that there is no space where the roots can squeeze through.


preparatory workAll root runners that you can see around the plant must be removed. Do not dispose of the rhizomes on the compost, they will continue to grow there unhindered.
Dig the trenchDig a sufficiently wide ditch around the plant. This should have a diameter of about 80 in bamboo and at least 30 centimeters in raspberries. Make sure that there are no stones in the trench. These could later be pressed against the root lock and damage it.
Introduce root barrierThe root barrier should not only be installed underground, but also look a few centimeters out of the ground to prevent the rhizomes from spreading above ground. The root lock must be closed well at its ends so that the roots cannot squeeze through.