Thursday, March 3, 2011

Bamboo - Growing the Stuff

A taste of spring, before we get to the subject of the day, bamboo. There little beauties were blooming at the edge of the upper pond, even though it's a bit cold. The daffodils are just up.

Fargesia (an unknown miniature version)

Bamboos are a sub-family of the grass family Poaceae and are classified as Bambusoideae, which is further divided into two tribes: Bambuseae, the woody bamboos, and Olyreae, herbaceous bamboos. The herbaceous ones are all tropical, so don't expect to find them at your local nursery. Bamboos are monocots and like grasses, bulbs, hostas and daylilies, emerge from the seed with one cotyledon, or seed leaf.

Phyllostachys aureosulcata

The main structural parts of a bamboo are the underground rhizome system, which has buds and roots, and the aerial culms (canes or stems) which support the branches and leaves. All the parts, with the exception of the fine roots and the leaves are composed of a series of alternating solid nodes and usually hollow internodes. This structure gives the bamboo great strength, light weight and flexibility.
One thing about bamboos that makes them quite different from other trees and shrubs is that the diameter and height of the shoot that emerges from the ground will stay the same throughout its life. As long as that particular culm is alive it will stay the same height and girth. As the plant gets older, it will produce thicker and taller culms, but each will remain that size, unlike a tree which adds new rings with each new season. New leaves, however, will appear, even on evergreen varieties, each spring. Each culm lives for a number of years.
The underground rhizomes form a matted and interwoven structure (which is why it is so hard to remove once established) that is quite shallow in the soil, and can extend for amazing distances from the parent plant, shooting up new culms from the nodes along the rhizome. I have found the tip of the rhizome 20 or 30 feet away from the clump ! This is just the most basic overview, since in my reference book, there is a section of 44 pages explaining, culms, rhizomes and leaves - interesting, but much more information that you need to know to grow some bamboo in your garden.

Pleioblastus pygmaeus

In choosing a bamboo for your garden, you'll find that they aren't all alike, any more that all other perennials are alike. Some like full sun, while others will grow happily in the shade. Some enjoy cold winters and others more moderate climates. In general, though, they are very versatile and will adapt to many different types of soil. The exceptions are very sandy and dry soil and wet, boggy places. This last fact is one way that you can control bamboo. You can plant it at the edge of a pond or stream with no worries about it crossing the water. As long as you start with a nice planting hole, bamboos will even tolerate heavy clay soils. Because of their matted rhizomes underground, bamboo is excellent for stabilizing steep banks where the soil is prone to slipping. The easiest way to keep bamboos from spreading where you don't want them is to plant them where you will be able to mow around them. Chopping off new culms with the mower will stop them from spreading where you don't want them. I have been told that the rings they sell to keep bamboo under control don't work very well. In theory they should, but I'm not surprised that the rhizomes will find their way under or over the barrier. I suppose if you sank a 55 gallon drum and planted in that you might get control, but I don't expect that the bamboo will be too happy being that confined.
Bamboos are not too fussy about pH either, and any soil in your garden will probably be fine if other things will grow there.
There is a bamboo for every garden. We have some tiny ones that never get over 18 inches tall, and there are others (not in my garden, but nearby) that are over 20 feet tall. Solid green leaves and variegate ones with green or yellow stripes, different colored culms, large leaves or small, narrow or wide. Some are even clumping forms that are quite well behaved and won't even try to take over your garden.
So, I'm not here to discourage you from growing bamboo, since I do so quite happily (most of the time), but rather to encourage you to research the types you'd like to grow and have a good plan to keep them under control. The book I use most is 'Hardy Bamboos: Taming the Dragon' by Paul Whittaker and published by Timber Press. There are a number of other ones out there and many books on grasses will also contain a section on bamboos.

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