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CONTENTS Some botanical details ~~~~<>~~~~ There are more than 200 forms of bamboo suitable for British gardens. Bamboos are giant members of the grass family and throughout the world there are about 90 genera with a total of around 1000 species. Since their earliest origins, millions of years ago, they have adapted and spread very widely, though unfortunately the ice age eliminated them from Europe and they have not been able to adapt to extremes of cold or dryness. Each year new shoots (culms) are produced from modified underground stems known as rhizomes. There are two types of rhizome system and this determines whether the a bamboo is clump forming or running. This division is not entirely botanical however as the cooler climate of the UK sometimes causes bamboos to remain as tidy clumps even though in warmer countries the same species would have the potential to spread. ~~~~<>~~~~ There are very few widely accepted common names for the
various bamboos so there is little alternative to using botanical names. These
are based on the Botanical Code and take the following form:- Genus – species
– variety or Cultivar. ~~~~<>~~~~ Flowering is relatively uncommon and intervals of over100 years are known. A particular clone is likely to flower almost simultaneously throughout the world but the factors influencing this are not yet known and there is no means of predicting when flowering is going to occur. Flowering may sometimes cause deterioration or death of the original plant but one consolation is that the seed which is then produced gives an opportunity to raise new varieties, as in the case of Fargesia murielae , which flowered during the 1990’s and is now available in a number of different clones, each growing to a different height. Fargesia nitida and its varieties are currently flowering and as the eventual effects are not yet certain, they have been withdrawn from sale. ~~~~<>~~~~ The canes of a bamboo, correctly known as culms, will not increase in height or thickness after their first season, although additional leaves and branches will be formed each summer. For this reason, the initial height at the time of planting is less relevant than it would be for conifers or trees, and likewise, any necessary trimming of the canes for packaging purposes has virtually no effect on the height at the end of the growing season. The height reached by new culms on young plants will increase each year as the plant gains strength until it becomes fully established. Mature height varies according to species, from groundcover of around 1ft. to clumps exceeding 20ft. It is also influenced by soil conditions and differences in the length of the growing season in various parts of the country. Heights indicated in the descriptions should be taken as a guide for northern gardens and may easily be exceeded in favourable areas. ( metric equivalents are shown in brackets and are mostly rounded off to the nearest whole number) When choosing species, account needs to be taken of whether to use a non-running clump forming type or a more spreading sort. Clump- forming species can be relied upon not to colonise adjacent areas. Those described as rampant need to be sited accordingly. Most others can be prevented from spreading unduly by occasional use of a spade. The spread of tall growing sorts is readily controlled by the destruction of emerging shoots in spring. Many of them are also edible at this stage as bamboo shoots. Groundcover types can be invasive and in small gardens they should be grown in containers or restricted in other ways such as planting in a position surrounded by lawn so that mowing will prevent the development of unwanted shoots. ~~~~<>~~~~ Micro-climate has a considerable effect on winter hardiness – being predominantly woodland plants, most bamboos prefer shelter from wind. The possible effect of frost relates not just to temperature but also to the duration of the cold period and to other conditions at the time such as wind. Fortunately, because of the insulating effect of the soil, the root system from which new canes will arise is unlikely to be harmed, especially if generously mulched. During normal winters, most bamboos remain evergreen with only minor deterioration in the foliage quality, but in extreme conditions leaves may be shed, usually to be replaced in summer. A few species, such as Fargesia murielae, will shed a proportion of their leaves in autumn but with little effect on their appearance during winter. Withering of the leaf margins of Sasaella etc. is normal and gives an interesting effect resembling variegation. ~~~~<>~~~~ Most bamboos are shallow rooted and enjoy a soil rich in humus, preferably with a surface mulch. Dry, shallow chalk soils would be unsuitable for most species, but Phyllostachys decora and Phyllostachys flexuosa may be successful. Generally though, pH does not appear to be very significant. Inherently vigorous species such as Bashania fargesia are capable of making good growth even on very heavy soil. On exceptionally heavy soils however, it may be an advantage to create a raised bed or to plant in a mound of good soil a few inches above the surrounding level in order to improve drainage for newly planted bamboos. The roots will then adapt and find their own level. Only a few species will tolerate very wet or very dry soil conditions. Occasional top dressings of general fertiliser are beneficial and watering of young plants is essential during dry conditions. ~~~~<>~~~~
Sun or Shade? The greatest degree of shading results when the canopy of nearby trees actually overhangs the growing site, whereas the aspect of the site or the amount of shade caused by the average house can often be ignored. The main problem caused by walls near the planting site is often not so much that they cast shade, but that they may deflect natural rainfall from reaching the roots of the plants. In cases where bamboos are exposed to too much sun, or are too dry at the roots, the leaves will temporarily curl inwards. This is an important warning sign especially when plants are growing in containers. ~~~~<>~~~~ Bamboos are tough plants so this is only a short list:- Insect attacks are rarely seen, but aphids will occasionally reveal themselves by the presence of "Honeydew" on the foliage, subsequently colonised by Sooty Mould. Good growing conditions are a deterrent and if necessary, proprietary sprays are effective. ~~~~<>~~~~ As yet, few bamboos have widely accepted common names so there is little alternative to the use of botanical names. We realise that this can be off-putting to begin with and for those who can't face reading through the whole list, the following may be helpful for selecting the variety with the attributes which are most important to you. Do please try though to look at the whole range, as each species has only been included because it has one or more special quality. In the full list we have tried to summarise as briefly as possible, these outstanding features, together with any possible limitations of each sort. Non-Running Stem Colour Foliage Plant Form
All-round Value for
Small Gardens Spectacular Landscape Effect
Bamboos Currently in Flower ( Fargesia nitida and its varieties) ** Description and photographs can be found by clicking on this name in the "Bamboo Stock List" This beautiful species and its various selected forms have been widely grown in the UK for over a century but many plants are unfortunately now in flower. The flowers appear in early spring and closely resemble those of grasses. The normal foliage gradually disappears, leaving only brown remnants of the flowers, inside which seeds can sometimes be found during the summer. Since Fargesia nitida has not previously flowered in this country, it is not known whether or not the plants will die as a result. In cases where a part of the plant remains vegetative, it may possibly survive, but it is likely that if the whole plant flowers, it will exhaust its limited reserves and then die. There is no effective remedial treatment. Because bamboos are propagated by division, each plant of the same clone is genetically the same age and their internal clock governing the flowering date will be set to the same year regardless of whether it has been growing in a garden for fifty years or has recently been purchased as a small plant.. Because the length of the flowering cycle of most bamboos is not exactly known, there is no way that it can be predicted in advance, so nurseries cannot be held responsible. On our own nursery, F. nitida began flowering in 2006 and was withdrawn from sale that year. Its varieties such as 'Anceps' , 'Nymphenburg',' Wakehurst', etc have also come into flower this year (2008) and have now been withdrawn from sale. What to do if your plant has flowered The simplest solution at present is to replace it with another species of Fargesia which will be similar but of course not exactly the same. Fargesia murielae or its varieties would be a good choice and it is not expected to flower again for at least fifty years. Fargesia rufa and Fargesia drachocephala are also good alternatives. Nurseries such as our own are currently raising a new generation of Fargesia nitida from seed and you can do the same from the seed from your own plant. It of course takes several years to produce sizable specimens suitable for planting. One of the earliest seedlings has been multiplied on a large scale by means of micropropagation but our own trials of bamboos produced by this method have so far not been at all encouraging compared to the performance of those produced by conventional division.
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Site revised
30/3/2008 Telephone: 01629 55010 e-mail: sales@uk-bamboos.co.uk |