Here are some of the frequently asked questions we get about bamboo.
Bamboo has a mixed reputation.
It intrigues, even fascinates, many people. The obvious connections to Asian art and landscaping are very important. It is perhaps the most widely used plant in the world for food, construction, etc.; although in our country it is primarily used as an ornamental landscape plant.
On the other hand, inappropriate planting of certain invasive species have led to bamboo's reputation as being ruinous to landscapes and impossible to eradicate.
- Are there any bamboos that won't run all over my yard?
Bamboo can be classed generally as runners (invasive) or clumpers (non-invasive). There are actually 6 recognized rhizome types described by how they grow and where the culms arise from them. Nevertheless, the two broader terms apply as long as you realized that a few bamboos can be classed as "open clumpers." These will spread to an area of, say, 20' in 10 - 15 years--a time frame in which a true runner could cover 1/4 acre or more if unrestricted.
- My neighbor planted bamboo and I'm afraid it will invade my yard. What can I do?
Check to see if it's a runner. If it's a Phyllostachys, it runs. If it's a Bambusa, it doesn't. That covers the two most common genera of bamboos you're likely to see here, although there are many species and cultivars of both.
- Simple rule:
- If it has a flattened stem and/or a groove or ridge on the stem, it's Phyllostachys (invasive).
- If it's round, it's Bambusa or some other genus of clumping (non-invasive) bamboos.
- What do I do if it's a runner?
Talk to your neighbor!
Perhaps a barrier can be installed (more on that later).
Even better, perhaps it could be replaced with a non-invasive type.
- Do barriers really work?
Yes, if they are correctly installed and monitored seasonally.
A barrier can be wood, metal, or very thick plastic (40 mil is the standard recommendation).
Rhizomes can get through any gap in the barrier, so proper joining is important. The barrier should be at an angle away from the bamboo. When a rhizome hits a barrier it will either turn sideways, go down under the barrier, or go up over the barrier. Rhizomes have been recorded going 4' down to get under barriers! But if it's angled outward the rhizome will always go up and can simply be snapped off when it is visible.
This is why monitoring is important! Rhizome growth begins in the spring and continues into the summer, so walking along the barrier once or twice a year may be all that is necessary.
A trench can be an effective way of making monitoring easier. The rhizomes will stick out into the trench and can be broken or cut off.
Concrete will block bamboo to some degree, but rhizomes will happily grow along the expansion joints. If the soil is moist, rhizomes can grow under concrete for short distances, or asphalt (particularly if it's got cracks in it) for surprisingly long distances. A pond can be an effective barrier, as rhizomes will only grow a short distance into open water. Bamboo will not usually grow into dry soil, but runners can make a great deal of growth with moisture from spring rains before summer drought stops their spread.
- What does bamboo want?
Plenty of water and reasonably good soil.
Bamboo is not drought-tolerant.
Full sun is fine for most types; there are some exceptions. Most will also grow in moderate shade.
All types, being grasses, respond very well to nitrogen feeding, especially in the spring and summer when rhizome and culm growth occurs. Lawn food is fine.
Cold-hardiness is a major factor in deciding which to grow in Northern California. Many are tropical, tender at 32F, and some are subtropical and will show unsightly winter damage here although they may survive. On the other hand, some species grow at 10,000' in the Himalayas!
- Members of the following genera are successful here; others may be:
- Phyllostachys, and
- Does bamboo grow well in pots? In the house?
Bamboo is great in containers as long as it gets plenty of water.
It will get root-bound quickly, and will be stunted by that, but will still be very attractive. It is a classic for bonsai.
As a house plant it is less successful. It needs very bright light and is very prone to spider mites. Bamboo grown outdoors will not take the transition to indoor living well and will drop lots of leaves unless it is gradually acclimated to the lower light.
- Which bamboos are best for hedges or screens?
Varieties of Bambusa multiplex. They have foliage nearly to the ground, are very dense clumps, and are from 6' to 15' tall. They can even be sheared.
Bambusa oldhami will make a tall, narrow screen, and Bambusa ventricosa (Buddha's belly) will make a big, broad screen.
- Which are best for groves?
Unfortunately, runners such as Phyllostachys make the best groves because of the wider spacing of their culms. Larger-culmed clumpers such as Bambusa oldhami can eventually be thinned out for more of a "see-through" effect, but only after many years in the ground. Bambusa vulgaris has a somewhat open clump habit, and Otatea acuminata even more so.
- Which bamboo are grown for shoots?
Most have edible shoots. Some are more palatable than others. Some tropical species accumulate toxins, so they need to be boiled before eating, but they are too tender to grow here anyway.
- How do you cure bamboo for construction or crafts?
Slowly and under moist conditions. It splits readily in hot, dry climates. There are some species with nearly solid culms, and their wood is highly prized for construction. Commercial distributors of bamboo products are listed in the ABS Source List.
- What can I plant under bamboo?
Not much, usually, unless the grove has been thinned out. The root systems are aggressive, the shade is dense, and the steady litter of culm sheaths make it hard for plants to compete. Tough rooted plants such as Mondo grass, Liriope, Nandina, Clivia (if frost protected), Aspidistra, or Ruscus might be successful.
- Does bamboo die when it flowers? I've heard Phyllostachys aurea is beginning to flower.
Bamboo hardly ever flowers.
Sporadic flowering can occur on plants that are stressed or root-bound, and don't usually lead to death of the plant.
Gregarious flowering is the flowering of one particular clone of bamboo, which, thanks to propagation and distribution by humans, may be a worldwide event. Some of the common species of bamboo die after gregarious flowering (this has been hard on the panda population at times, as they live almost exclusively on certain types of bamboo). Phyllostachys bambusoides did this in California in the 1970's, and since most plants had come from a single source nearly all died statewide. Otatea acuminata flowered a few years ago and most clumps died. The good news is that they set seed in great quantities first, so within a few years that species is readily available.
- Why is bamboo so expensive?
Because it is propagated only by division (since it almost never sets seed and most don't root from cuttings), so growers can roughly double or triple their stock each year.
- What are the other plants called bamboo? Here's a list of other plants called 'bamboo'!
© 2008 Don Shor, Redwood Barn Nursery, Inc., 1607 Fifth Street, Davis, Ca 95616
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