This summer, after 20 years, we went back to the beautiful Cevennes, in the south of France, near Alès. Of course a visit to the largest bamboo forest in Europe is a necessity. In this article we give a short impression of the visit.

Bambouseraie De Prafrance

Trench as root barrier

cross section: clumping vs running

Cornus contreversa ‘variegata’

© La Palmeraie

When creating a garden we naturally want to see results as soon as possible. However, the plants need time to develop. To give a good idea of the average growth rate of the various bamboo species, we have put the different species from our garden next to each other in this article.

Fargesia

Fargesia demissa ‘Gerry’

Fargesia denudata ‘Lancaster 1′

Fargesia denudata ‘Xian II’

Fargesia nitida

Fargesia robusta ‘Pingwu’ & Fargesia robusta ‘Campbell’

Fargesia robusta ‘Wolong’

Fargesia rufa

Fargesia sp ‘Jiuzhaigou 1′

Fargesia sp ‘Jiuzhaigou 4′

Phyllostachys

Phyllostachys vivax ‘Aureocaulis’

Pleioblastus

Pleioblastus pygmaeus

© La Palmeraie

Regularly, we receive questions whether bamboo can be kept in a container and which species is most suitable for this. In order to make this information available to all, we wrote this article with some basic principles. Also check out our article with a more complete view on the world of bamboo: Clumping & running bamboo: everything you need to know. 

In a container

There are many situations thinkable where you could only use container plants. Bamboo is a good choice for this kind of gardens. It gives an exotic look and is evergreen. Ideal as a natural separation for some privacy or to an ugly wall by example.

Points of attention

which container to use

A large container with enough depth is preferred. Not only will the plant be much more stable in windy conditions, this kind of container can held more soil and therefor will dry out much less quickly than when the bamboo is planted in a small pot or tray. Minimum sizes will be about 40 cm (1,4 ft) deep and 40 cm wide. The larger the container, the more autonomous the plant will be in terms of water needs. Also, the plant will do better when it gets the space it needs. Use a container with holes in the bottom so that no water will stay in the bottom to avoid rotting.

Soil

In principle, each type of soil can be used, although rich soil will be preferable. It can be wisely to mix in a few hands of water retaining crystals such as Aquaperla DCM®. These crystals absorb a large amount of water to subsequently release it again.

Watering

Bamboo needs a lot of water! Summer and winter. Especially on windy days, bamboo can evaporate lots of water, allowing the soil to dry out quickly. Fortunately, the plant also show its water needs: when leaves are starting to roll, the bamboo is thirsty. Better of course is the water before the leaves start to roll. Regular and generous watering is therefore advised. Of course they are not aquatic plants neither, so the soil should be moist but not wet.

Bamboo-species

In principle any bamboo species can be used in a container, but not all of them will do as well. The most suitable species for containers remains the Fargesia rufa we think. This species is hardy, grows fairly broad and becomes 1.5 to 2 meters (3,5 – 6,6 ft) high in a container. If it has to be tighter then the Fargesia sp. jiuzhaigou 1 also may be considered although this species rolls its leaves faster. A Fargesia robusta is also an option. On the pictures in this article you’ll see a Pseudosasa japonica in a tub. This species has varying success and was replaced by a Phyllostachys nigra in the meantime.

Maintenance & pruning

Besides the regular watering and adding some fertilizers during the growing season, the bamboo in a container does not actually require any particular maintenance. However, in spring, the bamboo can be tightened up by pruning the oldest (thinnest) canes just above the ground. If desired, the plant can be pruned at any time of the season and at any desired place. For example, to obtain a certain shape or maximum height. When the bamboo has become a full groove after many years, it may be taken out of the tub to divide into pieces and then be re-planted again.

© La Palmeraie

As soon as you speak about bamboo, first heard reaction is often “watch out with bamboo!”

In quite some gardens, bamboo is a serious plague rather than a beautiful asset. This is because of the fact that this exotic was often planted without prior notice, with all the consequences. It is not exceptional the hear about fences begin pushed aside, ponds being pierced or relationships with neighbors really being put to the test due to wandered of bamboo runners.  In this article you will find all relevant information in a clear and easy to read summary. 

Clumping or running bamboo?

Bamboo can be roughly classified into two groups; clumping and running bamboo. Each bamboo forms underground rhizomes, but in clumping species, growth remains concentrated to one grove. Depending on the species, the size of the final grove varies between 1 and 2 meters (3-7 ft) in diameter. With the running species, the runners can show up far much further from the grove. A few meters are bridged effortlessly. These species should therefore be limited if you wish to keep the bamboo within a certain area.

Cross-section of the root system; clumping bamboo on the left, running bamboo on the right

Root or rhizome barrier

When planting a running bamboo, you should seriously consider to install a root barrier as well. Note that not any material is suited. Concrete doesn’t form a serious obstacle by exemple and your bamboo eventually will get through! The only suited material is the HDPE plastic sheet available at your local bamboo specialist. This barrier exists in different heights between 50 and 70cm (20 & 30 inches). The price is usually around € 4.50-5.00 / stretching meter. The needed height depends on the species that you intent to use.

See this article for further information:
How to install a bamboo rhizome barrier

Large nurseries, sometimes deep trenches as well to limit their bamboo into a certain area. The rhizomes are hampered by the light. But for a typical, small sized garden, this method is probably not really suitable.

Bamboo: which species?

There are a lot of different bamboo species. Most gardeners prefer thicker canes but do not like the idea of having a runner bamboo. Unfortunately those two characteristics don’t go hand in hand. You will have to choose between rather thick canes or a clumping species. For the average gardener it maybe difficult to know by heart which species is a runner and which isn’t. And unfortunately you can’t always trust the seller neither.

Therefor we create a simple summary divided into running and clumping genera.

Mostly it is the Fargesia (clumping) and the Phyllostachys (running) that you will find in your garden center which makes it a lot easier to remember.  An other well known runner that was often planted is the Pseudosasa recognizable by its big leafs. Every genus does count multiple species of cours but within the genus they will have the same characteristic concerning running or clumping.  There maybe slight differences, as certain Fargesia species which do develop wider groves as the Fargesia sp. ‘Scrabida’, the Fargesia robusta ‘Wolong’ and the Fargesia rufa but the certainly are no running species.

The bamboo with those nice thick canes is the Phyllostachys vivax.

You will also find from time to time “new” species with nice sounding names both mostly it’s just a commercial way to sell classic species.

Water bamboo

In addition to the regular bamboo, there are also some Phyllostachys species that can maintain in much more humid conditions. They should not be expected to be water plants, but due to this adaptation, these species are capable of surving in areas that are regularly flooded. Below an overview:

The distinction between regular and water species is not always as easy to determine. For example, the P. atrovaginata and P. parvifolia resemble each other. An important determining feature is the air canals in the rhizomes. In this photo, it is therefore a rhizome of the P. atrovaginata.

Fargesia robusta

Fargesia denudata

Phyllostachys parvifolia

Phyllostachys kwangsiensis

Phyllostachys edulis

Phyllostachys nigra 'Borayana' in Bokrijk, biggest bamboo (in surface) in Belgium

Emplacement & planting distance

Bamboo is not very demanding in terms of emplacement. However, certain species are more appropriate as a solitary were others are perfect for forming a hedge. Also, some species do cope better on more shady spots were others stand well in full sun as well. For the best result, do inform yourself which species does fit your needs the best. As for the soil type, bamboo does not require any special adjustments. However, bamboo needs a lot of water, which means that too dry surfaces need to be watered much more in the summer.

When creating a hedge, the individual plant distance depends on how fast you want a tight hedge. If you plant 2 plants per meter (3 ft) you immediately will have a tight hedge. If you put 1 plant per meter, the hedge will close up after 2 to 3 years. If you plant even less, you can choose to divide your groves after a year of 3 and replant these divided bamboos  in the hedge. Best of all, the bamboo is planted about 100 cm from the yard limitations to prevent culms showing up at the neighbors too.

For growing in containers or large pots the Fargesia rufa is the most appropriate. But you will have to water sufficiently to prevent it from drying completely.

Care & pruning

Bamboo is a simple plant in terms of care. It needs little attention as long as it gets enough water. On warm days a water shortage will manifest itself by curled leaves. As soon as water is given (in time), the leaves will open again. Fertilizers for grasses can be used although special bamboo fertilizers do also exist. Pruning is not really necessary unless you want to model your grave a bit.

Generally, new culms are formed just once a year (exceptions do exist) in spring which grow out to a mature cane in matter of weeks. These newest canes are thicker than those of last season. It could be useful to thin out the grove once a year by pruning the older (thinnest) canes just above the ground. If desired, the side branches can be cut off the nodes wherever and whenever you want. Most bamboo species are hardy in our climate. However, the new culms can be protected in the early spring against night frost by means of a mulch layer.

Do not prune ugly canes too quickly, especially on the clumping species as the stock most of their energy in their canes. Do also not loose your hope after a severe winter. Who knows, the bamboo still will shoot, a bit later in spring.

Runners that show up too far away from the grove can be cut off using a spade. If it had enough roots you even can replant it again elsewhere.

Bloom

After the bloom, most bamboo species die completely. Sometimes is mentioned specifically that the species has recently flourished. This is because bamboo flourishes very rarely (up to many decades between bloom). Now you know that you can buy this species with a restful heart. This is, for example, often the case with the Fargesia ntidia varieties.

Our favorites

In order not to place a rhizome barrier, we mainly have Fargesia species planted. The Fargesia robusta ‘Campbell’ is our favorite for the hedge. As a solitary, we have a Fargesia denudata ‘Lancaster 1′ which bends over gracefully with the top-heavy canes. For a somewhat wilder effect we also planted a Fargesia robusta ‘Wolong’ as solitary. This species is a bit wider, but as the garden is big enough this isn’t a problem at all. Furthermore, we are also a fan of the Fargesia rufa. Not only is this plant very versatile; Solitary, hedge, tub, … he also proved to be very hardy.

Phyllostachys edulis

Phyllostachys aureosulcata 'Spectabilis'

Phyllostachys prominens - 11cm thick

Useful addresses

www.belgianbamboosociety.com – Belgian Bamboo Society website
www.bamboogarden.com – American website with a nice visual summary of different species
© La Palmeraie

Bamboo must not be forgotten in the exotic garden. They demand little care and are wintergreen. Unfortunately, bamboo suffers from a bad reputation. Throughout the years, bamboo was once planted in gardens, and often it were running species like the Pseudosasa japonica. However, there are also many non-running or clumbing species (see our article: Clumping & running bamboo: everything you need to know). But it’s the running species who become the most spectacular with their thick canes. By placing a root barrier (rhizome barrier) you can however manage these bamboo species. This way you can enjoy these beautiful plants with fear for any bad surprises. In this article you will read how to place such a rhizome barrier. 

Root barrier or rhizome barrier

Not every material is suitable as a root barrier. Bamboo has very strong rhizomes which will cross without effort materials like concrete. An excavated sewer pipe is therefore not an option. Neither is geotextile! Only the special HDPE, a stiff high density polyethylene plastic sheet of at least 1mm thick, is suitable. This sheet, available at bamboo specialists, exists in different heights between 50 and 70cm (20 & 30 inches). The price is usually around € 4.50-5.00 / stretching meter.

The appropriate height depends on the bamboo species. One species carries deeper than others. In addition, a few centimeters of margin above the ground must be taken into account as well. When the root barrier is too deeply dug, the bamboo can escape by running over the barrier. When the rhizome barrier protrudes a few centimeters above the ground, it is easier to check for any escaping runners every new season.

Emplacement

Running bamboo generally requires ample space. In the long run, even when using a rhizome barrier, a too small place will lead to escaping runners. Only when the grove is structurally thinned this can be avoided, although the bamboo will never get as beautiful as when it does has enough space. A few square meters for one grove is therefore no unnecessary luxury! The root barrier closes the ground from the rest of the garden. This causes the soil to dry out faster. Some hobbyist however, only place a barrier on one side, but keep an eye on the open side to cut off annual rhizomes. When using a closed barrier you need to water sufficiently.

Placing the rhizome barrier

Once you have found the right spot you can start digging. Remember well that placing a root barrier is though labour!

Step 1

When you have determined the exact emplacement, the grass can be removed.

Step 2

Once all the grass removed, the real digging can begin. And deep you might say! In this case a 70 cm (30 inch) barrier is installed which will protrudes a 10cm (3 inch) above ground. The chosen species doesn’t have rhizomes that deep into the ground but does escape easily over the top of the barrier. As there will be to much soil to put back again, a part of it is discharged.

Step 3

After many hours (!) digging, the trench all way round is deep enough and the rhizome barrier can be placed. Before closing the trench, you can choose to tie the ends together (Figure 1.) and fasten them with a bolt (red dotted line), or to tighten the ends inwardly (Figure 2.) . The advantage is that with this last method the roots are returned in the center of the grove again (red arrow). However, this closure should be kept an eye on any escaping runners. Because this is only in one place, it is very easy to do. We have chosen for this last type of closing.

Step 4

After planting the wanted bamboo species (Phyllostachys vivax ‘Aureocaulis’), the emplacement is filled with a rich soil and covered with Coocnut chips. This way the emplacement stays free of unwanted weeds.

Aftercare

In the next period regularly watering is needed. The first 3 years no pruning is needed. Afterwards you can prune yearly the thinnest (and so oldest) canes the lighten up the grove for a more healthy growth and thicker culms year after year.

© La Palmeraie

There are several reasons thinkable why you would want to divide your bamboo. Perhaps your plant is becoming simply to big for your garden or you want to multiply the bamboo in a easy way. In this article, we describe step by step how to proceed when you want to multiply your bamboo. These instructions are applicable to any bamboo species!

When?

In principle, you can divide bamboo all year long, but early spring (February-March) is preferable. At that moment of the year there are not many new shoots yet and the bamboo can shoot directly on its new spot.

Material needed

First of all, make sure you have a solid spade. Bamboo roots (rhizomes) are very tough. Therefore, they can be quite difficult to cut off. A sharp, solid spade eases the work somewhat. Also, remember that you do not force the spade when digging out. You would not be the first to break your spade in half.

Dividing

Step 1

Look around the bamboo grove for some easy to acces culms. This way you can divide the bamboo without damaging the grove itself. Try to push all the other bamboo canes aside a little bit to move around freely. Some help can come in handy here.

Step 2

Carefully place the spade between the isolated culms and the other canes. Do not start directly in the middle which would be to solid to cut through, but instead place the spade all the way to the side to cut of bit by bit. Push the spade into the ground firmly with one foot.  You should feel the resistance of the rhizomes.

Step 3

Pull the spade out, move it only a couple of inches side wards and push it back in the ground to cut the next bit of rhizomes. Continue this way processing slowly inch by inch in a circle all way around the selected culms to cut of all the rhizomes. When the spade can not be pushed down due to too much resistance, move back aside some inches to cut a smaller part and try to spread the resistance more. Do not use the spade to chop of the rhizomes, you’ll only risk breaking the culms!

Step 4

Once you have cut off all the rhizomes all way round, take all these canes together to pull while continuing digging around. Push your spade slightly to try to lift the divided culms without breaking your spade of course!  After a while of pulling, pushing and digging the culms should come loose.

Step 5

Plant this new grove on its new spot as soon as possible. A few hours can be bridged, but obviously, avoid leaving it for hours in your car in full sun to ensure that the bamboo does not dry out. Generally, bamboo is not so demanding for soil type. However, it is useful to provide a plant hole in advance. In this way, the new pole can be planted as soon as possible. Fill the plant hole with a rich soil and provide enough water.

Aftercare

Bamboo needs lots of water, especially after dividing. Water regularly depending on your local weather conditions. The soil must not dry out completely. Even more water is needed if the grove is planted in a container. Do not panic if the leaves are drying out and start falling of. Some foliage drop out is completely normal after this kind of intervention.

© La Palmeraie