One of the classic plants of the Japanese garden is the maple, Acer palmatum. The common Japanese names for maples are ‘momiji’ derived from ‘leaves turning red’ or ‘kaede’ derived originally from ‘frogs’ hands’. Autumn trips to the mountains to see the beauties of the changing leaf colours are called ‘momiji-gari’, maple leaf hunting.
Spring foliage of Acer palmatum ‘Katsura’ (meaning ‘wig’)
There are thousands of cultivars, many with poetic and beautiful names. Here are some Japanese words used in the names of Japanese maple varieties.
Ao – blue-green
Ba – leaves
Beni – deep red
Fu – variegated
Gasa – umbrella
Hime – princess or little
Ito – fine thread
Kin – gold
Koto – a stringed instrument
Acer palmatum ‘Koto-no-ito’
Maiko – dancing girl
Murasaki – purple
Nishiki – brocade, by extension variegated or textured
In China, Japan, and parts of India, the rare phenomenon of bamboo flowering is considered a bad omen. In China, a proverb warning of ‘pestilence or famine’ presaged by bamboo flowers was reported in a letter to Kew from a British Medical Officer who noted that bamboo flowering in Hong Kong in 1894, 1896, and 1898 coincided with outbreaks of bubonic plague. It was during this epidemic that Alexandre Yersin discovered both the bacillus responsible for the plague and the fact that it was present in rats. Given that we now know that the abundance of food provided by bamboo seeds from mass flowerings creates booms in the rodent population, and that fleas on rats transmit plague, the proverb seems well-founded.
In 1958 the authorities in Mizoram in north eastern India were warned that the bamboo was flowering and famine would follow. They dismissed the reports as local superstition. The bamboo flowered, the rat population exploded and a ‘rat flood’ consumed every scrap of every crop in the area. The resultant famine was so bad it led to an armed uprising.
Wild bamboo flowering in Guangdong, 2013
In India this phenomenon is known as ‘Mautam’, bamboo famine. 90% of all the bamboo in the area is the same species, a tropical clump former with a relatively stable flowering cycle of about 48 years. It all flowers at once (gregarious flowering) and then dies. Not all species of bamboo are so predictable or, fortunately, so devastating in the effects of their reproduction.
In fact, there is a great deal we don’t understand about bamboo flowering, despite records of the phenomenon going back some 2000 years in China. What triggers it? How do plants of the same clone, growing in different locations, know to flower at the same time? Why are the flowering cycles so varied (between 1 and 120+ years)? Why do many bamboos die after flowering?
Sporadic flowering of Phyllostachys praecox ‘Viridisulcata’, 2020
Many factors have been proposed as possible triggers over the years, from external environmental factors to an internal clock. It is generally believed now that the flowering does follow an internal time table, modulated slightly by environment and cultivation. The exact mechanism is not yet understood. In the 1970s, the ecologist Daniel Janzen theorised that bamboos flowered in synchrony as a method of overwhelming seed-eating predators. So many seeds would be produced that they could not all be eaten and some would germinate and grow. Plants that fell out of sync would not have this protection, their seeds would be eaten, and their genes would not continue.
Complete flowering of Phyllostachys nigra ‘Megurochiku’, 2019
A group of biologists at Harvard extended this theory to explain how the long flowering cycles evolved. Supposing in a forest of bamboos which flowered every year, a few mutated to flower every two years. They would have longer to prepare and more stored energy to produce seed. Their seeds would have an advantage and their offspring would increase. More and more bamboos would flower every two years, and eventually those flowering every year would not produce enough seeds to survive predation. They would die out. Then suppose a few bamboos mutated to flower every three years. They also would not have the protection of flowering and producing seed in synchrony and would die out. What about mutations that flowered every four years? Again, they would have the advantage of more time to store energy but still flower in synchrony with plants on the two years cycle. So bamboos which flowered in multiples of the cycle would gradually predominate, and the cycle would get longer and longer over time.
Phyllostachys nigra ‘Megurochiku’ showing signs of recovery, 2020
What does all this mean for bamboos in the garden? First of all, bamboos flower at very long intervals, so the plants in your garden may never be affected. However, given the likelihood of them dying if they do flower, it is a good idea to plant a mix of different species if you are planting a bamboo hedge, to protect against expensive losses if you are unlucky.
Secondly, there’s nothing you can do to stop a bamboo flowering. The only thing to do is wait and see. It may only be sporadic flowering, which shouldn’t harm the plant. If it is complete flowering (anecdotally more common in clump-forming bamboos than runners) the plant is both more likely to die and more likely to set seed. You can water and feed it if you wish, and it may recover, but it will take a long time to do so if it does and will look awful in the meantime, so most people dig them out or at least cut them down. I have found seeds more likely to germinate in situ, if they escape the notice of hungry birds.
Fargesia nitida seedlings germinating in the crown of a tree fern, 2018
In 20 years of collecting bamboo, I have had three species flower completely out of a collection of more than a hundred: Fargesia nitida, Chusquea gigantea, and Phyllostachys nigra ‘Megurochiku’. The Fargesia, a clump former, produced viable seed and died. The Chusquea and the Phyllostachys, a giant clumper and a runner, next to one another in my garden, flowered at the same time last year. A forest of seedlings has appeared, but I have no way of knowing their parentage. The Phyllostachys is recovering. The Chusquea has as yet shown no signs of doing so, but I have not cut it down yet as I will not be opening my garden this year and can live with the eyesore if there’s any chance of regrowth. It is a favourite plant and I will be very sad to lose it. Fingers crossed, but as I have learnt over the years, you might be able to predict famine and plagues, but bamboos rarely do what you expect them to do.
The ‘japonica‘ of Japonica Plants is, of course, a specific epithet meaning ‘from Japan’. Botanical Latin is wonderful for many reasons but its ability to label a plant with an instant description or location is one of the best. Here are some more specific names connected with Asia.
Athyrium nipponicum var. pictum
nipponicum from Japan
yedoensis, yesoensis, yezoensis from Tokyo
yezoalpinus from the mountains of Hokkaido, Japan
Ephedra sinica
chinensis, sinensis, sinica, cathayense from China
pekinensis from Beijing
setschwanensis, sichuanicus, szechuanicus from Sichuan province
Bergenia emeiensis
emeiensis from Mt Emei, a botanical hotspot in Sichuan
One of the most wonderful and most exasperating things about bamboos – and indeed many other plants – is that they vary so much and so unpredictably. The answer to almost any question I am asked about bamboo begins, “Well it depends, but generally…” With that in mind, there are not always hard and fast answers to how a bamboo will behave, but let’s generalise a bit.
Bamboos have different rhizome structures which dictate their growth patterns. Broadly speaking they can be divided into clump formers and runners. Clump-forming bamboos send out new rhizomes which turn up to become new culms. Runners send out rhizomes which send up new culms along their length and continue on. Clumping bamboos therefore send up new culms around the edges of the clump, expanding slowly and evenly.
Typical, closely packed culms of clump-forming Fargesia rufa
Runners can send up new culms at quite a distance from the main clump, expanding rapidly and unpredictably. However, clump forming does not necessarily mean small! While typical clumpers (e.g. Fargesia) send up new culms very close to the clump, some (e.g. Yushania and Chusquea) have rhizomes with a long ‘neck’ which can grow outward 30cm or so before turning up into a culm. These can form a large, relatively open clump very quickly.
Chusquea gigantea, a ‘long-necked’ clumper and a real giant.
Other clump formers can fountain outwards from a tightly clumped base, requiring space to appreciate their form. The foliage of such a bamboo may easily be four times the width of the base.
Fargesia rufa, a clumping bamboo which forms a mushroom of foliage.
Running bamboos are harder to generalise about. Some (Sasa and Chimonobambusa most notably) are rampant and aggressively spreading. A few are very reluctant to spread or even bulk up (some of the rarer Phyllostachys bambusoides varieties, for example – which is why they are rare). Most are somewhere in between. Unfortunately, it’s impossible to say exactly where in that range a given plant will be in a given garden situation. Some people have found that their bamboos are more prone to wander in dry soil; the theory is that they spread in search of moisture. Several plants in my garden have done the opposite, spreading rapidly in rich soil with plenty of moisture.
Widely spaced culms of Phyllostachys bambusoides ‘Castillonis Inversa’, which might be called a ‘gently running’ bamboo
A plant of Phyllostachys vivax ‘Aureocaulis’, for example, has run in almost a straight line in both directions from the original planting. In four years it has spread from a five litre pot to a five metre wide plant. As it is a giant timber bamboo I was not expecting it to be compact, so it has plenty of room in the middle of the garden, well away from my neighbours.
Phyllostachys nigra, the black bamboo, is notoriously variable in habit. This may in part be due to the number of different clones available. P. nigra was one of the earliest bamboos introduced to the U.K. in 1823 and is still one of the most popular and most widely available. Some plants remain in a tight clump whilst others spread quickly. If you plant this bamboo, it might be wise to put in a partial root barrier or at least keep a close eye on it.
One of the myths that I often hear about bamboo is that all bamboos will run eventually. This simply isn’t true. A clump forming bamboo does not have the capacity to send out long runners. However big it gets it will not suddenly pop up elsewhere in the garden. What is true, however, is that all running bamboos do have this capacity. Many of those available will stay in a well-behaved clump. Some may, after many years in the ground, send out a single runner which is easily dealt with. Many others will wander if allowed to but can be kept in check fairly easily. And some should really not be planted in the ground at all, unless you have acres which you would be happy to see invaded.
Phyllostachys aurea ‘Koi’
Just to demonstrate the range of ‘running’ bamboos, the plant above has been in the ground as long as the five metre wide P. vivax ‘Aureocaulis’. It has spread perhaps six inches in that time, and remains the tightest clump of any of the forty odd species I have planted out, including the clump-formers.
Bearing in mind the huge range of bamboos available in the UK, with a little research and perhaps some input from a specialist nursery, it should be possible to find a suitable bamboo for almost any garden situation.
Few things symbolise the tranquillity of a Japanese garden quite as well as a textured green carpet of moss.
Ophiopogon formosanus and moss
Whilst it is possible to grow and transplant moss, and it can spread fairly quickly when happy, it has quite specific needs (shade, moisture, slightly acid soil) and is not suitable for all situations. Here then are the top alternative ground covers I have found to achieve a mossy effect in different growing conditions.
Selaginella kraussiana
1. Selaginella kraussiana (Spikemoss). This primitive plant grows happily in full or partial shade as long as it has adequate moisture. Sometimes listed as tender or semi-evergreen it has proved surprisingly hardy and evergreen here in Suffolk, and spreads at a respectable pace. Different forms are available, including aurea and ‘Gold tips’ but the differences in colour are slight.
Sagina subulata ‘Lime’
2. Sagina subulata (Pearlwort; Irish or Scotch moss) This rapidly spreading ground cover forms beautiful hummocks of green which give a lovely natural moss effect. This is a good ground cover for a sunny spot as long as it is not allowed to dry out; grown in too much shade it tends to become tall and stringy. It has inconspicuous white flowers in spring. Again, different forms are available, of which ‘Lime’ seems to be the best.
3. Chamaemelum nobile ‘Treneague’. (Roman Chamomile) Another good ground cover for sun, this plant has the added attraction of deliciously scented feathery foliage. It grows best in light, well-drained soil and struggles on heavy clay. ‘Treneague’ is a dwarf form which does not flower and is used for chamomile lawns. Chamomile can withstand light foot traffic.
Soleirolia soleiroleii
4. Soleirolia soleiroleii (Mind your own business, Baby’s tears). A good, rapidly spreading and very attractive ground cover for damp shade. It may be deciduous in a hard winter but will regrow. Popular in Victorian times, it was used as a decorative edging to conservatory staging.
Moss growing through Selaginella kraussiana
Like many things in gardening, finding the right ground cover can involve a bit of trial and error. These plants are species I have tried in my ‘Japanesque’ garden. All except the chamomile, in partial shade on clay, have worked well for me and all are worth trying. A number of different mosses are also establishing themselves on the ground and on logs and stones, some of which are merging with the planted ground covers to create a very pleasing effect. It is well worth experimenting with a mixture of different plants to provide a variety of textures and greens, and give the full effect of a moss garden.
Bamboos are beautiful plants that add height, structure and movement to a garden. They come in an astonishing range of culm colours: black, green, yellow, blue, olive, grey, purple, white, brown, red, blotched with brown, yellow with green stripes, green with yellow stripes, green with a black sulcus, and green with multi-coloured stripes. The culms may be grooved, zig-zag, bulbous, or just ridiculously large. The leaves can be tiny and delicate or huge and tropical.
Blue bloom on culms of Borinda papyrifera
Evergreen plants, bamboos add interest to the garden year round. The shooting season begins in early spring with some Fargesia species and continues at least until August with the late shooting Phyllostachys bambusoides cultivars. The shoots themselves are often interesting, even grotesque, rather than ornamental but it is fascinating to watch the speed at which they grow. Some species attain their full height of 40ft in six weeks!
Congested internodes on a culm of Phyllostachys aurea ‘Koi’
Once established in the ground, bamboos are very resilient, low-maintenance plants. They are unfussy as to soil and most are very hardy. They can be grown in situations ranging from full sun to full shade, and are practically pest and disease free in the UK. They appreciate feeding and supplementary water but don’t need them, and established plants can survive periods of drought or flooding. Similarly, although they benefit from occasional tidying, they don’t require pruning.
Variegated foliage of Pleiblastus fortunei
Hopefully some of this has persuaded you to think about growing bamboos. However, there is no denying that some people have come to regret planting them, so it’s important to consider the possible drawbacks.
Bamboos are big plants, often bigger than people expect them to be. This is not helped by the tendency of garden makeover programmes to put 8ft specimen bamboos into a small space in people’s gardens as if they are going to stay that size. In fact they can gain height and width very rapidly. When a bamboo reaches maturity, it can send up culms twice as thick as the previous year’s and half as tall again. If you have a big garden it can be very exciting to see new, larger culms coming through. In a small garden, however, a running bamboo can quickly become a problem and whilst it is a myth that all bamboos eventually run, even a clump former can get too big for its space.
Which leads on to the second potential drawback. No one who has ever dug up an established bamboo has any wish to repeat the experience. Removing a running bamboo that has got out of control can be an expensive and time-consuming process, leaving aside the potential problems with angry neighbours.
Sasa kurilensis ‘Shimofuri’
The best thing to do is to buy a bamboo from a specialist nursery who will have a far wider range than the average garden centre and should be able to give you useful advice based on experience of growing these wonderful plants. Choose the right bamboo and site it carefully, and you will have a fabulous plant that will enhance any garden, and possibly the beginnings of a lifelong obsession.
Japonica Plants Nursery 