Does a root barrier make sense for Chinese reeds? Limit the reeds with a rhizome barrier

Miscanthus sinensis, also known by the names of Chinese reeds and elephant grass, is a common one Found sweet grass, which, due to its dense growth, is often kept as an ornamental grass and privacy screen will. Like other grasses, the extremely robust species can multiply quickly and form runners. Many gardeners associate the word “runners” with the need to contain the roots so that they do not drive away other plants or damage structures. But is that necessary with the reeds?

Caution: risk of confusion!

Please note that the Chinese reed can be confused less often with other plants that are also called elephant grass. They all have one thing in common that they grow lush, tall and expansive and therefore the designation as elephant grass is appropriate. In addition to Miscanthus sinensis, these are:

• Napier grass (bot. Pennisetum purpureum: 450 - 750 cm high
• Giant Chinese reed (bot. Miscanthus giganteus): 300 - 400 cm high
• Ravenna grass (bot. Saccharum ravennae): 100 - 450 cm high

They all need a rhizome barrier to keep the strong one Urge to spread to suppress. However, the big difference between the plants is the height. In Central Europe, Miscanthus sinensis is usually only two meters high, in rare exceptional cases up to three meters, while the elephant grasses often grow larger and more expansive. Therefore, you should definitely pay attention to the botanical name when purchasing, as the individual grasses require significantly different care.

The grasses also spread rapidly in the ground and can cause great damage. Chinese reed, also called Miscanthus condensatus (synonym), is not really a candidate for a root lock, except for a few situations.

When does a root barrier make sense?

The classic Chinese reed is the only Miscanthus species that doesn't really need a root barrier. However, in a particularly favorable location, the roots can spread strongly and up to five meters in all directions within a short time. In the long run, this can lead to major damage. You should use a root barrier to limit specimens in the vicinity of the following elements in particular:

• Tube
• cables
• Garden ponds
• House walls
• Paths made of cobblestones
• Pavement terraces
• Building foundations

With these elements in particular, it makes sense to pack the reeds and suppress the forceful expulsion. Even sturdy plastics can be penetrated in the long term if the runners of the plant are older and stronger. The big problem with Chinese reeds is the rate of growth. Compared to other reed species, the runners form quite slowly, which is not a cause for concern in the first few years after planting. Then suddenly there is serious damage to the nearby structures. The advantage: The strong budding is a sign of an ideal location, which makes it sensible to set a barrier.

tip: The subsequent installation of a rhizome barrier is not a problem with Chinese reeds, it just requires a little more work, since all the runners that have already formed have to be shortened. The costs remain the same, only the time required to install the lock is significantly higher.

Size and cost

Buying a rhizome barrier for the Chinese reeds to limit the urge to spread is not really that expensive. However, this depends on the size and the extent of the Chinese reed so far. Retrofitting is usually more expensive, as the plants are often larger and therefore a larger root barrier is necessary.

We recommend root barriers made of high-pressure polyethylene (HDPE), as is used for bamboo. These should be selected with a thickness of 2 mm and a height of 70 cm, which costs an average of eight to ten euros per meter. The order length is calculated as follows:

Replanting

If you plant the rhizome barrier together with the reeds, then the necessary length is calculated as follows:

Plant hole diameter x 3 = order length

On average, one square meter is required per copy, which brings the typical order length to three meters. That would be acquisition costs of 21 to 30 euros.

Subsequent suspension

The order quantity of a subsequent block can be calculated in the following way:

• mark the four corner points of the reeds
• Draw a 2 to 3 meter line from each corner point
• mark again
• Connect the outermost markings with tape
• Measure diameter
• Multiply the diameter by 3

Since a network of roots has already formed before retrofitting the barrier, a larger order quantity is necessary in order to be able to place it and not damage the roots. Usually you have to pay around 70 to 150 euros for the subsequent installation.

You will also need a Locking railthat you should best get from the same provider. These are offered on average for prices of 25 to 40 euros for a height of 70 cm. Other providers equip their locks with an adhesive surface that closes them and does not incur any additional costs. When calculating the order length, it is essential to note the desired final size of the Chinese silver. If you want it to grow even further, be sure to order more so that it has enough room for its roots. This is the only way it can absorb nutrients and water from the earth.

tip: The use of garden fleece or roofing film for a flat roof as a rhizome barrier is theoretically also possible, but not recommended in the long term. This is because of the ends that have to be joined together via a seam or other locking device, which allows the roots to expand in one direction.

Possible problems after installation

If you do decide to put a lock in place, it is important to know about the possible risks. Above all, these have an impact on other plants and the vitality of the reeds:

1. Stunted growth of neighboring plants

If the distance of one to two meters to other plants is not possible, they can suffer from stunted growth due to the rhizome barrier. Since these roots hit the barrier, insufficient nutrients are no longer absorbed, which leads to a deficiency. So plan well when you place the barrier so as not to put other garden plants under pressure.

2. Unequal aspect ratios

It is also problematic if you do not place the Chinese reed in the middle of the root barrier. One side of the reed suffers a lack of nutrients because the root strands there do not have enough space. Therefore, you need to be careful to place the reeds as centrally as possible.

As long as you keep these points in mind, you shouldn't have any problems after installation. Since the space for the reeds and other plants is reduced by the barrier, it must be placed in such a way that there is no lack of space. Transplanting to one location is sometimes recommended.

Narrowing down Chinese silver: Instructions

If you want to limit your Chinese reed with a root barrier, all you have to do is install it after purchasing it. For this you need:

• spade
• shovel
• Gardening gloves
• saw

Then do the following:

1. Planting hole

The first thing to do is dig the planting hole. If you use the reeds together with the barrier, measure the required size using a tape. If the height of the barrier is 70 cm, dig the planting hole between 60 and 62 cm deep. In doing so, remove any root remains that you come across.

2. Dig up the plant

In the event of a subsequent insertion, the plant is first carefully dug out of the earth. To do this, mark the required pit and work your way from the outside to the inside. Check here whether runners have formed, which you can remove with the saw so that Miscanthus sinensis cannot spread any further. In the case of particularly large specimens, you should not completely dig the plant out of the ground, but only dig out soil along the cordoned off line and remove the runners.

3. Use root barrier

Now place the root barrier in the hole, guide it once along the edge and close it either with the splint or the adhesive device. If you have decided on a lock with adhesive, you must definitely wait for the manufacturer's drying times. If the adhesive surface cannot dry completely, pieces of earth will get into the interface, which means that roots could penetrate through the barrier. For this reason, you should definitely wait until the recommended drying time has passed.

The root barrier must be approx. Protrude 3 to 5 cm from the ground. This is the only way to prevent it from spreading directly below the surface of the earth.

4. Insert the plant

Then the plant is placed in the middle of the pit. A second person can help so that the reeds are really placed in the middle. Fill the pit with the excavated earth and spaces on the outside of the barrier with earth or sand. Proceed in the same way with retrofitted copies.

5. Compact earth

Finally, compact the earth with your feet. Kick it tightly and don't miss an inch. The lock is now in place and effective.