Bamboo is one of the most versatile plants on our planet and has been used by man since probably the cave man. A lot of people are scared to grow it in the garden either from a bad experience or being told it is a thug which will take over the garden. In this blog I hope to dispel a few of those fears and recommend a few varieties to try.
Why grow a bamboo?
It is a very architectural plant which will become a highlight in the garden and also provide an evergreen windbreak. They are very good for diffusing light in the garden handy for those semi shade plants that you may want to grow, unlike conifer which blocks out light altogether. I get a lot of pleasure wandering through the garden and hearing that lovely rustling sound a breeze makes in the bamboo and looking up through the moving leaves at the diffused sunlight.
Another aspect of growing bamboo is the myriad of different coloured culms that you can get with them ranging from black, green, yellow, red and blue. You can also grow the odd climber through them to give an unexpected splash of colour. At the nursery I have a wisteria creeping through a Phyllostachys nigra and once heard a customer remark “ooo! I didn’t know bamboo flowered!”
A term you will see used in this blog is culms. By definition this is the part of a bamboo that is often referred to as a cane. Culms are the living plant, canes are what has been cut off and is dead.
Bamboo is a rhizomatous plant which means that the plant has underground stems with nodes These rhizomes underground bear a lot of similarities to the stems above ground the main difference being that the nodes underground are closer together and produce culm buds and roots whereas the nodes above the ground for the most part produce branches and leaves although sometimes ariel roots can be seen emerging from these.
Basically there are two types of bamboo Pachymorph and Leptomorph.
Pachymorph bamboos are the safest bamboo for planting in the ground these are to the layman clumping varieties And the nodes on these bamboos can produce several culms. As a general rule nodes are also quite close together which gives them the clumping aspect. There are some pachymorphs that are a little wider spaced and these are refered to as loose clumping. I find an easy way of remembering pachymorph is to think of a round elephant foot (pachy) and imagine that as a tight round pattern.
Leptomorph bamboo is a whole different ball game in bamboos and this is where you can find the thugs. I do have these types of bamboo planted in my garden but a watchful eye is kept on them! The rhizomes on these tend to have wider spaced nodes and you tend to find that root and culm nodes alternate on them. The Phyllostachys bamboos belong to this group and I find it very frustrating when I see them sold as safe clumping bamboos. Climate and soil influence the growth habits of these plants. Long hot dry summers encourage vigorous rhizome growth with wide spaces between nodes whereas short cool wet summers restrict the growth between the nodes giving a clumping habit. If a bamboo is dry it will go looking for water and as a consequence will run! Easy way to remember name Leptomorph leaps all over!
Most bamboos have a shallow rooting system and this can quite often be found within a spades depth. The reason for this is the plant is trying utilise the rain and get the first chance of any moisture falling from the sky. This can be a disadvantage to other plants especially if they are moisture lovers but I find regular mulching in the garden helps with this. Conifers still are the biggest moisture hoggers. I struggle with plants under a cedar but I am quite happily growing other plants near my bamboos.
Dont be tidy with bamboos, they are evergreen yes but shed leaves most of the year. These leaves are an excellent source of food for the bamboo and should not be cleared away. Occasionally a bamboo will have a big leaf shed this is natural so don’t panic new leaves quickly emerge. When a new culm emerges you will see a sharp pointed tip coming out of the ground at this point in time be very careful because these shoots are quite fragile and if damaged you will not get a nice tall culm. You will notice that on each node there is a protective covering this is called the culm sheath and it main purpose is to protect the branch and leaf buds on the culm node. Once the culm has reached its height these culm sheath drop off and the branches and leaves start to emerge. As with the fallen leaves these sheaths are a valuable mulch and feed supply for the bamboo so brush them under the main part of the plant if you have to be tidy.
So next question that I quite often get asked is can I grow this bamboo in a pot? I personally prefer to see bamboo grown in the ground but if you want to grow a potentially invasive variety you may want to consider using a rhizome barrier. There are some barrier materials available via garden centres/ nurseries and online. You need to buy something that is smooth and tough, don’t think that concrete, bricks or porous membrane is going to be adequate. If a rhizome can get purchase on a surface it will go through it. It will eat concrete for breakfast! A shiny surface will give it no purchase and the rhizome will slide along it. When digging your planting hole get it big enough and you should not need to go any further down than 50cm. Line the hole with the barrier material and leave about 5cm sticking above the ground. The reason you need to do this is a rhizome can emerge above the ground and then go back down, this way you can be aware of an escaping rhizome and deal with it. Quite often a plastic dust bin with the bottom cut out can be used.
Non invasive varieties at some point may need sections of the clump chopping away if getting too big but these will not invade you borders or lawn in quite the same way as a thug.
In answer to the question of growing in a pot. Yes you can grow bamboo in a pot use a straight sided pot because at some point you will need to take the bamboo out of the pot either to pot on or divide. Bamboo can get pretty tatty in a pot if not fed and watered adequately they are completely reliant on you caring for them, Because they are evergreen they constantly transpire so need regular watering. They are reasonably drought tolerant but neglect can lead to leaf loss, you do get warning signs and the leaves will curl along their length at this point make sure they get water, recovery can be very quick and you almost hear the plant sigh. Winter can pose big problems for bamboo in pots because quite often water is not available to the plant because it is frozen and it sheds all of its leaves to preserve itself. The Black bamboo (Phyllostachys nigra) is one of the worst culprits for this and unfortunately the most popular one in pots. I have had customer in their panic when this has happened cut all the culms off at the base thinking because bamboo is a grass this is the best thing to do. DON’T DO THIS! With a bit of feed and water in the spring those culms will push out new leaf in the case of the black bamboo this may be as late a June/July but you will not be sitting looking at a pot with perhaps only 2 or 3 new culms emerging.
Going back to the comment a customer made about bamboo flowering, they do, after all they are grasses. In the case of Pachymorph types this is the death knell for the plant and it will die. In the case of Leptomorphs they have the ability to partially flower so can recover. The interval for bamboos flowering be very infrequent and the periods between flowering may be anything from 20 years up to hundreds. Because most bamboo is produced from divisions you have got to bear in mind that they are clones. This means when a certain variety is flowering that will occur on every plant from that clone flowering wherever it is in the world.It is completely unpredictable and has been a subject of great interest to botanists. However a product of flowering is hopefully viable seed and as a result we can end up with different varieties within a species. A good example was when Fargesia murielae flowered it produced up to 20 variants with some quite unique differences. If you are going to buy a bamboo it can be useful to find out when it last flowered. If you are considering then please buy from a responsible nursery even if it costs a bit more. I once attended a show and there was what we term in the trade ‘A trolley merchant’ selling Fargesia nitida which he had cut the flowers off the previous night! I reported it to the organisers but suspect they did nothing. These people do not help our trade.
I hope that this blog will inspire you to grow a bamboo with confidence. After all anything grown in your garden has had to gain your confidence.
Any of the Fargesia types which I have listed some of below
Murielea : Bimbo, Simba, Jumbo and Super Jumbo
Nitida: which has recently flowered and now some sizeable plants on the market from seed so probably a safe bet from flowering for a few years but no guarantee!
Robusta: as suggested by the name a very robust bamboo with reasonably sized culms for a Fargesia. Does not suffer from leaf burn and looks good all year round. One of my personal favourites.
Scabrida sometimes known as the Asian Wonder bamboo. Nice vigorous variety with culms emerging quite early in the spring.
Rufa: A thin culmmed bamboo but very good for screening and grows up to about 7ft. Also an early shooting variety.
Jiuzhaigou: About 4 clones of this numbered 1-4 a commercial name given to this is Jiu. This is a seedling clone from nitida and has lovely dark reddish culms on emergence which branch in second year with culms turning tawny.
Another good Pachymorph are the Chusqueas of which the main one seen is culeou. A unique solid stemmed bamboo from Chile also known as the foxtail bamboo. You may occasionally see a variety called gigantica this is not a bamboo for a small garden with culms up to 30ft and a very deep rhizome system to support those heavy culms but amazing!
Bambusa and Thamnocalamus are also good pachymorphs but I find these can defoliate a bit more readily in Winter.
Some of the safer Leptomorphs. Just remember conditions dictate growth and you need to keep an eye on them. Could go rampant in Cornwall well behaved in Scotland.
aureosulcata can grow lovely crooked stems.
aureosulcata f. aureocaulis a golden coloured of the bamboo above, very pretty and popular.
Some slightly mischievous varieties:
bissetii good wind break variety which retains good leaf throughout winter and can get quite tall.
vivax a very large bamboo with impressive culms the plain vivax has green culms there is a yellow culmed variety with a green stripe called f.aureocaulis which is nice with bottom beaches trimmed off to show the magnificent culms then there is a reverse one called huanvenzhu with green culms and a yellow stripe.
A lot of my bamboo knowledge has been acquired from books and practical experience I must thank Paul Whittaker from PW Plants in Norfolk who shared his knowledge and passion of bamboo with me. If you are looking for a definitive book then his publication Hardy Bamboos taming the dragon is an invaluable resource.