Home & garden

Root barrier - material, effect and correct installation

Some plants form rhizomes that can spread uncontrollably. So-called root locks or rhizome locks can prevent this.

The heart of every hobby gardener opens when it blooms and thrives in the garden. However, some plants do it somewhat abundantly and displace their plant neighbors with their roots. The plants not only multiply in the garden in an apparently uncontrolled manner, they can also lift sidewalk slabs and take over the entire garden. With a root barrier, growth-friendly plants are put in their place. If root locks are installed immediately during planting, you will save yourself trouble and effort. You can find out why you should not do without a root lock, what it does and how to install it in a few simple steps.

What exactly is a root barrier?

Root locks prevent plants from spreading uncontrollably. Simply put, the roots are kept in a confined space. Root is not always the correct expression. Some plants do not form conventional roots, but rhizomes. These soil sprouts ensure that certain plants spread quickly and in an uncontrolled manner underground. In this context, one often speaks of rhizome barriers. However, both terms are identical.

By the way: Anyone who buys ginger bulbs in the trade has nothing but a rhizome in their hands.

What are root locks made of and what do they look like?

Root locks do not look at their function at first glance, because they are sold in roll form. The hobby gardener can determine the dimensions himself and cut the foils accordingly. Root locks are made of plastic. Polyethylene with a particularly high density is preferably used. The approximately two millimeter thick film can withstand even vigorous plants without any problems. Pay attention to the designation polyethylene (HDPE). Root barriers made of polypropylene (PP) are also common.

Every now and then the hobby gardener also helps himself and uses plastic or metal tubs that are embedded in the soil before the plant is used there. Root locks made from the remains of pond liner, roofing felt or other tarpaulins can only be recommended to a limited extent. A delicate lily-of-the-valley may be able to be put in its place, but a strong bamboo will probably never last.

Some drops of sweat will cost you if you put concrete slabs in the ground as a root barrier. Polyethylene films are much easier to put in the ground and are therefore the better choice in any case.

Alternatives welcome?

Smaller plants can also use a worn mortar bucket as a root barrier. However, do not use metal buckets, these could rust. Conventional roofing film is also suitable for some ornamental grasses or sea buckthorn bushes. Raspberries that grow well can alternatively be limited with root fleece.

How does a root barrier work?

Root locks must have some properties to effectively stop the rhizomes.
Important features are:

  • strength
  • frost resistance
  • Insensitivity to sunlight
  • safe from rodent bites
  • free of pollutants

Strength is particularly important. The root barrier must effectively withstand roots and rhizomes and must not be penetrated by the shoots. Even in severe frosts, the root barrier must not break or leak. The frost develops some strength in the ground. Root locks should also be placed above ground. Therefore, the material must be resistant to sunlight. There is also life in the ground. Therefore, the material must not be nibbled on by mice or moles. It is also important to prevent the plants from spreading, but not to unnecessarily pollute the soil. Therefore, make sure that the product is free of harmful substances when purchasing.

Which plants should get a root barrier?

Now, when you take a tour of your garden, you may be wondering which plants need a root barrier. Below you will find an overview of some plants that should be equipped with a root barrier.

bambooBamboo grows particularly quickly and its rhizomes are said to blow up ceramics themselves. Garden bamboo alone does not need to be rooted. You can keep its growth in check with concrete boundaries or regularly prune the roots.
EssigbaumVinegar trees are undemanding and attractive. However, vinegar trees are also poisonous in all their parts and have an extensive root system. Root locks or bucket keeping are ideal. Root barriers should be used at least 40 centimeters deep.
mintMint is particularly popular as a herb. If you plant a small plant in your garden, you will soon be surrounded by a sea of ​​mint. Mint travels through the entire garden without a root barrier. The root barrier should rise about ten centimeters above the ground in order to prevent it from spreading above ground.
raspberryRaspberries find many fans and should not be missing in any kitchen garden. The hobby gardener should keep in mind, however, that the sweet fruits quickly develop rhizomes and thus take over the garden. Even if the raspberry is considered a flat root, the root barrier should be set at least 40 centimeters deep.

Install root barrier - this is how you proceed

The creation of the root barrier should be considered when planning the crop. Every plant needs a certain space in order to spread and develop well. If the roots are narrowed too much, the plant cannot develop and atrophy.

" Tip: Root locks should always be planned generously. If the plant feels restricted, it will not develop as desired.

Based on the example of the growth-friendly bamboo, it should have an area of ​​approximately eight square meters. Generous planning ensures strong plants. This also includes the depth of the planting hole. This should measure about 80 centimeters. There should be no stones inside the root barrier. These could cause cracks in the film if they are displaced by the growing plant. The root barrier should not only run underground, but also protrude a few centimeters from the ground. This prevents the roots from spreading over the edge of the root barrier.

The planting hole should narrow towards the bottom. This automatically restricts the growth of the roots and the plant grows more bushy and vigorous upwards, instead of focusing all of its energy on the development of the roots.

Pay attention to the location

It is not uncommon for various ornamental grasses or bamboo to be planted as a hedge. This certainly has its advantages, since the plants are fast growing. There are a few things to consider when attaching the root barrier. The roots should not penetrate into the neighbor's garden or dig out slab panels. Particularly aggressive plants can even attack neighboring buildings or the sewage system with their rhizomes. To ensure that this can be reliably excluded, the root barrier must be attached with particular care.

Install the root barrier correctly - step by step

  1. Get root lock
  2. Determine location
  3. Measure area
  4. Raise the ground
  5. Insert root barrier
  6. Fix the root barrier at the ends

First find the right location for your plant. Determine which room you would like to allow and measure the area accordingly. Be as generous as possible so that the plant develops vigorously and is not restricted. After the soil has been excavated, the root barrier is inserted. This should form a ring that completely surrounds the hole in the ground. The end is to be secured with a rail made of aluminum or stainless steel. This is screwed to the film. For this it is necessary to drill holes in the root barrier. Alternatively, the root barrier can also be welded.
Place the root barrier above ground too. The film should protrude five to ten centimeters from the ground. The surface area must be checked regularly. Any rhizomes visible there must be removed.