Plant Profiles

 

 

 

Bamboo

Fancy growing a well-known oriental style plant to use in many types of garden? Check out Bamboos.

They are actually giant grasses but differ by having woody stems or culms and a unique life cycle.

Bamboos occur in tropical, subtropical, and temperate regions of the world and are found from lowland elevations to 12,000 feet. They are commercially and culturally significant. As ornamental plants, they are favoured for their Oriental form and feel.

Bamboos have an erect, airy form with grass-like leaves on multiple branches. They typically either form clumps or single-stemmed groves. Some are climbing. They are evergreen but drop older leaves continuously. These dropped leaves form a weed-proof mulch layer under mature groves.

Bamboos have botanical characteristics that distinguish them from your typical shrub or small tree and from their relatives, the grasses.

Bamboos spread by rhizomes. New culms develop from these rhizomes in an outward spreading fashion. Culms reach their full height 2 to 6 months after emerging from the ground. New culms can grow phenomenally fast once the general plant is mature and the rhizome system is established. Some have been observed to grow almost 4 feet a day. They grow slower, however, from newly transplanted plants. Frequent watering and fertilising with a high-nitrogen fertiliser will speed and increase growth. On the other hand, slower growth can be achieved by controlling watering and feeding. Mature bamboo can tolerate drought but will not spread into dry or overly wet soil.

Branches begin to development after the culms reach maturity. Apical or topmost branches emerge first followed by lower branches. Flowers form at intervals of 20-120 years. Bamboos have highly unique flowering habits. The most unique is the gregarious flowering habit. In these bamboos, plants of the same bamboo species flower simultaneously all over the world for a period of 2-3 years, after having gone for long periods without flowering. After the flowers develop and produce fruit, the culms die almost simultaneously, again world-wide, and are replaced by seedlings. Other types of bamboo species flower sporadically and only the flowering culm dies afterwards rather than the entire rhizome system. Other bamboos flower continuously and do not die after producing flowers.

As a family, bamboos occupy a wide range of habitats, including wide elevation differences, dry tropics, humid tropics, wastelands, swamps, and riverbanks. They also tolerate a wide range of soils though almost all genera grow best on rich, well-drained soils. They exist in the forest understorey where their shallow root systems do not compete with the deeper roots of the surrounding trees. In logged forests, however, bamboos take advantage of the increased light and commonly become the dominant vegetation.

Choose a bamboo variety carefully. If a grove is desired, research underground barriers to control spread into unwanted areas. Tilt the barrier so that it forces the rhizome to emerge from the ground for easier control. Clumping bamboos are not as invasive as running bamboos and so can be used with confidence in a small landscape. Both grove and clumping species are good for shelter hedges, screens, and windbreaks.

When purchasing a bamboo plant, pot-bound root systems need not be avoided. This is a good indicator of rapid growth after planting. Use a small hand-held rake to loosen and tease apart root systems before planting. Encourage as much outward direction of roots as possible in the planting hole.

Bamboos are best planted in autumn before the first frost. They can be planted in the spring and container bamboos can be planted anytime. Take care to avoid planting in periods of high heat or drought. Dig the planting hole at least an inch wider than the root ball and fill with a mixture of native and new potting soil.

Prune and thin bamboo clumps and groves yearly to encourage vigorous culm development. Cut dead culms close to the ground so that their stumps do not crowd the growing ones.

On species of Phyllostachys , like nigra, it is a good idea to trim off the lower branches and leaves to reveal a ‘trunk’ which provides an unique effect.

Here are a few ideal bamboos to grow:

Bambusa multiplex ‘Fernleaf’

Fargesia fungosa

Phyllostachys aurea

Phyllostachys bambusoides

Phyllostachys nigra

Phyllostachys glauca

Pleioblastus kongosanensis f. aureo-striatus

Pseudosasa japonica

Sasa veitchii

Yushania polytricha

Most are available from nurseries around the country

© Lee Mullen  
Plant Profile with kind permission of 
  Kernxotica