New Garden Bamboo's


By Jos van der Palen


Not yet ten years ago any new bamboo was seen as a possible enrichment. At this very moment the available assortment counts hundreds of species. So it's time to reflect. Therefore we hold our pace to see what our collecting mania has delivered us so far. New possibilities will be given attention as long as they seem an asset.
To avoid mentioning a lot of names instantly, we take the Central-European climate with the cold winter of '96/'97 in mind, when we had minimum temperatures of 18 to 22 degrees below zero.


A Gordian knot

The major problem with bamboos is that the borderlines between the species are often hard to define. As a rule intermediate forms will disappear eventually in the process of specification. But, the evolutionary process of the northern bamboos is, like the rhododendrons and eucalyptus, still going on vividly. Many bamboo species tend to intermediate forms along the borders of their distribution range. More than 75 Fargesia species have been given very precise botanical descriptions. New specimens collected in the wild differ most of the time so much from the botanical descriptions that one is hardly able to point out to which species it actually belongs. A recently introduced Fargesia robusta with large leaves fits more to the botanical description than the specimen we already knew.
A few seedlings, brought in from the nature reserve Jiuzhaigou in northern Sichuan show an obvious relationship with Fargesia nitida, but differ so much from the original description of this species that it is virtually impossible to consider these as real nitida's. Almost any time when the species Fargesia nitida is collected in its vast distribution range, the specimen involved is surprisingly different from the ones that are already in culture.
In Phyllostachys another problem pops up. As a horticultural and agricultural species for thousands of years hardly any natural location can be found these days. Many bamboo's that are propagated for their usefulness over and over, were once collected as superior specimens at their natural locations or selected as seedlings after a flowering period. Many of them were later unjustly described as real species. Considering the diversity of the Fargesia murieliae seedlings, the chaos after thousands of years of Phyllostachys culture is not difficult to imagine. But as long as there is no better system of classification we have to make shift with what we have.


Tall and big bamboo's

Tall and big. Maybe these two words form the moving spring of our obsession. Almost anyone is struck by the magic of the giant culms. Talking about the size of our bamboos, we are very much like anglers. Supported by broad arm gestures proportions are pointed out. My first wish was, to stick to the angling business, to grow bamboos as tall as fishing rods in my garden. Now I have redefined the limits and many of the culms have outsized the average fishing rod.
The Central-European climate seems not good enough to species like Phyllostachys pubescens and Phyllostachys viridis to reach gigantic dimensions. Also Phyllostachys bambusoides seems to prefer warmer summers and milder winters. Phyllostachys violascens, formerly considered being a 'bambusoides' but at present seeming to belong to 'praecox', developing also in less warm summers quickly big culms, but is susceptible to dry winds and low temperatures. Even the two bigger Phyllostachys nigra forms 'Boryana' and 'Henonis' turn out to be not strong enough to withstand long cold winters. Phyllostachys vivax, together with its breathtaking yellow culmed form 'Aureocaulis' and the green and yellow 'Huanwenzu', was praised towards heaven by the Chinese for its hardiness, was disappointing after the severe winter of 1996/'97. At less protected locations this bamboo could not cope with the combination of hard wind and severe frost. The yellow culms of 'Aureocaulis', if not frozen off, got covered with brown blots. But in areas where winters don't strike hard regularly, Phyllostachys vivax remains a most impressing giant by its vigour and big culms.
During the last six years, since China made it possible, plane and shiploads of bamboos were sent to Europe. Sadly enough a lot went already wrong during digging up and packing. In the box, labelled Phyllostachys propinqua, we found at least four different species. The Phyllostachys vivax box caused even more confusion. It was sheer luck that the yellow culm bamboo's sent together with Phyllostachys vivax 'Aureocaulis' were easy to recognise. All this caused a lot of confusion and misunderstanding. A part of the bamboo's imported as Phyllostachys propinqua appeared to be in flower and not very hardy. We imported this particular species in order to get much material of the 'Beijing' or 'Li Yü Gan' clone. A bamboo that was introduced in the late eighties. This robust bamboo of outstanding hardiness had already earned some fame and is by far superior to the specimens that were imported later as Phyllostachys propinqua. In that period a few hardy giants came to Europe, but we are still breaking our minds about their identification. Two of them survived the severe winter of '96/'97 without problems and produced in three growing seasons culms of about 4 cm diameter. One of these might be a strong Phyllostachys dulcis, despite the frost sensitive clone from the USA with the same name we knew already. The other bamboo looks very much like a Phyllostachys iridescens but without stripes.
A giant that has the power to develop well in cooler areas and colder winters is Phyllostachys parvifolia. This one should not be confused with a small leafed form of Phyllostachys nuda that has been sold under this name. The hardiness of this small leafed bamboo is superior to Phyllostachys vivax, but similar in its vigour. On the list of possible assets to the gallery of giants Phyllostachys prominens should not be absent. This bamboo with prominent protruding nodes shows an enormous vigour and a more than good hardiness. We just have to be on the lookout for the coloured varieties of these species.
Two pretty hardy bamboos for a warm location are the quite similar species Phyllostachys atrovaginata and Phyllostachys virella. Both are not tall growing, but do produce big culms. Both produce a typical incense or 'sandalwood' scent when the culms are rubbed. Only the shoots of Phyllostachys virella are of a slightly lighter colour. As to me these are two forms of one and the same species.
A real giant with a total different appearance is Bashania fargesii. Notorious for its expansive nature this hardy, large leafed species is a good one given room to move and sheltered for hard winds.
Within the group of not so tall and big bamboo's nothing has changed very much. Phyllostachys aurea has proven to be not well suited to the Central-European climate, but both Phyllostachys aureosulcata and Phyllostachys bissetii are undisputed at the top. These two are closely followed by species like Phyllostachys angusta, Phyllostachys humilis, Phyllostachys decora, Phyllostachys nuda etc. If culm colour and hardiness are the main criteria Phyllostachys bissetii is the best in green and Phyllostachys aureosulcata 'Aureocaulis' in yellow and 'Spectabilis' in yellow with green stripes. The slightly less hardy Phyllostachys arcana 'Luteosulcata' is favourite when the culms have to be green with yellow variegation. In black we still have to be satisfied with the not so strong Phyllostachys nigra. Maybe a bit less spectacular, but with its own peculiar appeal Phyllostachys aureosulcata 'Harbin' with its grooved culms might be an asset to this group. Six years after its discovery the reversed form, Phyllostachys aureosulcata 'Harbin-Inversa' seems to have hardly left the UK. The variegated Phyllostachys aurea that is now in flower and seeming to revert to the green form has found a replacement in the hardier Phyllostachys bambusoides 'Albovariegata'. Some leaves of this species are even of a coppery colour in the shadow.
A clumping species Neosinocalamus affinis was described by the Chinese as hardy to minus 15 ? Celsius. When at last a specimen of the cultivar 'Flavodorivens' was in the position to prove itself in our climate, this bamboo could withstand a few degrees frost at its best. The high expectations were not proved, possibly due to a mistake by the typist.


Semiarundinaria

Among the stately growing group of Semiarundinaria S. yashadake 'Kimmei' with yellow culms and green striping seemed to add something. De green form Semiarundinaria yashadake proved, hand in hand with Semiarundinaria viridis, to be one of the hardier species. Sadly enough Semiarundinaria yashadake 'Kimmei' turns out to be less frost resistant and is probably another species.
Brachystachyum densiflorum is a new kid on the block in this group of upright growing and hardy species. It's not easily to confuse with other species by its conspicuously coloured shoots.


Pseudosasa

Pseudosasa japonica lets us down as an evergreen during severe winters. It's just because of its recuperative power that we can find this large leafed bamboo still in our gardens.
If we want a hardy and evergreen bamboo, Bashania quinchengshanensis with similar emanation and a height of over 3 meters is a great addition to the large leafed bamboos. Possibly this bamboo with a much to long name will fit well within the range of variation of Bashania fargesii. Two Pleioblastus species Pleioblastus amarus and Pleioblastus juxanensis belong also to this group because of their bigger culms and large leaves and are well prepared to survive severe winters.


Fargesia

Until now about 80 species of this complex group of clumping bamboos are described. A number of them are now placed in the new genus Borinda. Without doubt this group contains the bamboos we dream of since long. Due to their high altitude and inaccessible natural locations new Fargesia's are difficult to collect. A nice job for the real plant hunter. For the trade in this group we will find hardy species with bigger culms which will be an answer to the bad reputation of the expansive nature of, for instance, Phyllostachys.
If Ernest Wilson in 1907 had collected a Simba type of Fargesia murieliae we would have lived with the conviction that this species grows to a height of two meters at the most. It seems odd that no bambusero picked up the idea of exploring the Shennongjia area of the Chinese province of Hubei to study the natural variation of our hardiest and most successful garden bamboo. Whatever giants and dwarfs, upright or pendulous or with different leaf shapes might be found there: they would put the major part of the offspring of our Wilson clone in their shadow. Due to the self-pollination we will have to find satisfaction in a limited variation that makes it difficult to realise proper selections.
Some of the better selections are 'Jumbo' with yellowish green culms, and 'Kranich' with reddish sheaths. The latter, very similar to the motherplant, got mixed with old generation. This caused some confusion and we have to wait for the real 'Kranich' until all 'old generation' plants have exposed themselves by their flowering. The lower growing form 'Simba' is better replaced by a better selection. As far as we know, apart from the Wilson clone just one other Fargesia murieliae has been introduced in Europe under the name of SABE 939. This one started, as was to be expected, also flowering. Possible cross-pollination with the 'old' Fargesia murieliae might provide 'new blood' and perhaps new forms. Fargesia robusta has gained some popularity as a non-running bamboo. Although the hardiness is unlike Fargesia murieliae, this species with its contrasting paper-white culmsheaths tolerates quite some frost on a sheltered spot. In between several new forms have been introduced. The most remarkable has very large leaves for a Fargesia and makes the name robusta well understandable. Whether this form is as hardy as the 'old' robusta will remain a question until a next severe winter.
Spring 1995 I received a fax from Shanghai. Someone collected two bamboo species in the mountains of Gansu. Was I interested? Everything that grows there is interesting, so we decided to let the plants come over. One of them was a real shadow loving form of Fargesia nitida. The second one was harder to identify. Although Fargesia rufa seems the correct name, this bamboo meets the description of Fargesia dracocephala partially. This bright green Fargesia with its shiny and elegant leaves seems not to exceed three meters in height, but proved to be one of the hardiest and most evergreen in the cold winter of '97/'98.
An attempt to have the most desired Fargesia payrifera, with its big culms and a possibly good hardiness, collected in Yunnan resulted in three beautiful but not very hardy species belonging to Borinda and Yushania. At this moment we assume that these are Borinda albocerea, Borinda lushuiensis, Borinda perlonga and a weird half-climbing Yushania species.
Spring 1997 we received the outcome of another expedition. One Fargesia nitida collected in Nanping was surprisingly different with its shiny leaves, but is apparently a representative of the species. The most remarkable bamboo was a Fargesia labelled Fargesia scabrida with culms of about 2 cm diameter. The winter of '97/'98 with lows to -12 C caused no problems and the high altitude location (Pingwu/2600 m) where it was collected allows us to presume a much better hardiness.
This elegant bamboo has nicely upright growing culms, unlike Fargesia utilis with 3 cm diameter culms growing under an angle of 45 degrees.
Autumn 1997 we got another couple of Fargesia's that was collected in the wild. One of them is a dwarf. This northerly growing and therefore probably hardy bamboo grows to one and a half-meter and represents the 'missing link' of the non-running assortment. Due to the long journey eventually only one Fargesia demissa survived. At the same time a Fargesia denudata from Xian came along. Like Fargesia nitida the variation within this species seems enormous. This plant resembles the specimen collected by Roy Lancaster in the Min Shan (Min Mountains) in 1986, but has smaller leaves. This Min Shan denudata and the wonderful nitida-like bamboo from the Jiuzhaigou Reserve in Sichuan were collected as seedlings. Hand in hand with the seedlings of Fargesia dracocephala and Fargesia murieliae they represent at this moment the most important non-running bamboo's of the new generation. Concerning flowering we don't have to fear much from these plants the first eighty years.
Of course other important species have been introduced without my knowledge. Maybe the new bamboo for our region grows somewhere, well hidden for our eyes, waiting to conquer the European market in a single blow. Or maybe this bamboo we are all waiting for grows in a garden or collection, undiscovered for its lifetime.
It is for sure that the bamboo's we dream of are to be found somewhere in China or in the South American mountains perhaps.
When we display the same drive as the rhododendron collectors in their time the diversity of the assortment of useful bamboos will increase considerably and supersede quite a few species to the background


Translation: Edward Soldaat