It’s easy to fall in love with bamboo. It’s a beautiful plant with tall, elegant canes and thick, leafy greenery. Bamboo has a rich history and thousands of uses. But many gardeners have come to dread bamboo, because some varieties will spread out of control and take over the whole garden, becoming almost impossible to remove. That’s why the more experienced gardeners choose to plant clumping bamboo. Clumping bamboos offer all the grandeur of a noble grass without the nuisance of an invasive species.
|Bambusa||Subtropical clumpers that come in an enormous variety of shapes, sizes and colors|
|Fargesia||The most cold hardy genus of clumping bamboos|
|Himalayacalamus||An Asian genus native to the lower elevations of the Himalayas|
|Otatea||Clumpers native to Mexico, Central America, and Colombia|
Choose a clumper and stop the spread
Before deciding what sort of bamboo to plant, it’s important to understand a few of the basic fundamentals about bamboo gardening.
Q: Is it possible to plant bamboo and beautify your garden without the bamboo running out of control and becoming invasive?
A: Yes! If you plant a clumping type of bamboo, you will have a much easier time keeping it contained.
Q: What’s the difference between running bamboo and clumping bamboo?
A: There are more than a thousand known varieties of bamboo, but we can lump them into two basic categories. Running bamboos have leptomorphic or monopodial rhizome roots, which continue to spread and easily become invasive. Clumping bamboos have a much more compact root system, with pachymorphic or sympodial rhizomes. These U-shaped rhizomes tend to grow upward instead of outward, resulting in a well-contained and non-invasive bamboo plant.
Read more about the dangers of planting running bamboo in these articles:
- Running bamboos: Why must you run?
- Notorious runners: The most invasive varieties to watch out for
- Is bamboo illegal?
Q: How big will a clumping bamboo get?
A: The size of a clumping bamboo can vary greatly. Although compact by bamboo standards, a mature clumping bamboo will be at least 3 or 4 feet in diameter, and could grow to 15 or 20 feet wide. Some varieties of clumping bamboo grow faster and spread large than others. These fast-growing clumpers have pachymorphic rhizomes, but rather than just an inch or two, they can grow over a foot long. We call these open clumpers, and they will require a bit more maintenance.
In any case, it’s still importance to maintain a clumping bamboo, inspecting the roots and cutting back old culms. But a clumping bamboo will require far less maintenance than a running bamboo. To keep a clumping bamboo more compact, it’s relatively easy to remove the outermost canes. Just cut them down to the ground with pruners or a saw.
Selecting a clumping bamboo variety for your garden
As you can see, there are many advantages to planting clumpers instead of runners. But keep in mind, there are times when it might make more sense to plant a runner. If you want a fast growing bamboo to fill in a privacy hedge, for example, a running bamboo will work better. Or if you need a cold hardy bamboo, runners are usually a better choice. Most clumpers are not very cold hardy, with the exception of Fargesia.
Now that you’ve decided to planting a clumping variety, it’s time to look at the best choices of bamboo genera and species.
One of the most diverse genera of bamboo, Bambusa includes some of the most attractive and appealing species. And rest assured, every member of this genus is a clumping variety.
B. oldhamii: Oldham’s, as it is commonly known, is probably the most popular species of bamboo in all of North America. This towering timber bamboo can easily reach 50 feet high in ideal conditions with a good water supply. With long, straight poles that can get up to about 4 inches in diameter, it can be useful for all sorts of crafts and construction projects. The plant will typically spread to about 10 or 15 feet across, so allow it some space. But fear not, it won’t take over like Vivax, or one of those super aggressive varieties of Phyllostachys.
B. guangxiensis: This clumping bamboo is called “Chinese dwarf”, but it can actually grow up to 20 or 30 feet tall. It’s a very attractive species and easy to keep contained. The foliage on this bamboo is especially thick and bushy, so it makes a pretty good privacy hedge compared to other clumpers. It prefers warmer, subtropical climates and will not tolerate freezing weather.
B. ventricosa: Another favorite among bamboo lovers, Buddha Belly has some of the most interesting and attractive culm structure of any bamboo. Available in a number of cultivars than range from Giant Buddha Belly (Bambusa Vulgaris cv. Wamin) to Dwarf Buddha Belly, it’s practically a must-have for any serious bamboo collector. This plant earned its name from the bulbous internodes of its culms. The unusual shape makes it a great centerpiece for an Asian style garden. The giant variety can get up to about 45 feet tall and 15 feet wide. But the dwarf variety is of course more compact. It can even be contained in a small pot and grown like a bonsai with dazzling results.
Other popular Bambusas include Alphonse Karr, a beautifully striped bamboo, and Bambusa multiplex “Tiny fern”, a dwarf variety that only grows a couple feet tall.
Most kinds of clumping bamboo are native to the warmer and more tropical climates. If you’re looking for a clumper that can withstand deep freezes in the winter, your best bet is probably something from the genus Fargesia.
F. murielae: Commonly known as “umbrella bamboo”, many consider this to be among the most beautiful varieties for cultivation. New shoots have a light blue hue, turning dark green and yellow with age. Growing this bamboo in a shady area will help preserve the rich blue shade. Thin shoots will get about 12 feet tall, and it’s hardy down to -20º F.
F. nitida: “Blue fountain bamboo” earned its name from the dark purple, bluish culms and the thick, cascading canopy of foliage. One-inch poles can get to about 15 feet tall, and thrive in temperatures as low as -20º F.
F. dracocephala: “Dragon head bamboo” has thick culms growing to about 10 feet, with a thick, weeping leaf canopy that can provide a good privacy hedge. Not recommended for hot, humid climates, but cold hardy down to -10º F.
F. rufa: A compact, thick and bushy variety, Rufa much prefers the cooler climates, and also does well in partial shade, protected from afternoon sun. This species is hardy down to -15º F. Thin culms grow to about 10 feet tall.
F. scabrida: Another colorful variety, with shoots that come in shades of orange, blue and purple, eventually turning deep green. Also known as the “Asian Wonder,” it grows well in sun or shade, and is hardy to -10º F. Mature plants get 10 or 15 feet tall, with culms less than an inch in diameter. Although it’s a clumper, it does have a vigorous growth habit, making it a popular choice for many gardeners, but a point of concern for others.
Fargesia sp. ‘Jiuzhaigou’: This species includes many interesting and cold hardy cultivars, including “red dragon” and “black cherry”. As the names suggest, these are some more colorful varietals. With thin culms growing to around 10 feet, this is a more compact species of bamboo, but cold hardy down to -20º F.
Native to the lower elevations of the Himalayas, these clumping varieties originally come from Bhutan, China, Tibet, India, and Nepal.
Himalayacalamus hookerianus (Himalayan Blue): The richly colored, powdery blue culms give this bamboo an especially pleasing appearance. It prefers warmer weather, but also grows well around ponds and in containers. Culinary tip: fresh shoots of the Himalayan Blue are edible and are said to be quite tasty.
This is one of the most widespread genera of bamboo to come out of Mexico. The name of this genus comes from the Nahuatl word “otatl”, meaning bamboo.
Otatea acuminata (Mexican Weeping Bamboo): A versatile species, this bamboo does well in a variety of conditions. Near the ocean, it’s not bothered by the salty sea spray. In California, it can tolerate the dryness. It’s native to Northern Mexico, after all. But it’s also cold hardy down to about 20º F. And in small gardens, the weeping bamboo does quite well in a pot. The thin poles grow up to 10 or 15 feet tall, but the gracefully cascading leaves are what give the plant its unique appeal. It also has a dwarf variety, in case you’re looking for something especially compact.
More slow spreading bamboo
In addition to the popular genera of clumping bamboos listed above, there are a few more options for those who fear being overrun by vigorous grass. Some bamboos just don’t grow very big. While other species can exceed 100 feet in height, others don’t grow any larger than a pencil. Naturally, the smaller they are, the easier they will be to keep in check.
We’ve written a complete article about dwarf bamboos and ground covers. Most of the dwarf varieties are runners, such as Pleioblastus fortunei “Dwarf whitestripe”, Pseudosasa owatarii, and many species belonging to the genus Sasa. But even though they are runners, the culms are short and thin, and fairly easy to cut back. It is essential, however, that you remember to cut them back and inspect the roots on a regular basis. That means at least once a year in a cold climate, or twice a year in a warmer climate.
Clumping species like Bambusa multiplex “Tiny fern” and “Tiny fern striped” will be even easier to confine to a limited area.
Containing and maintaining bamboo
Now, just because you’ve planted a clumping variety instead of a runner, it doesn’t mean that your work is done. Every garden requires some maintenance, and that’s just as true for a clumping bamboo. It certainly doesn’t require the same degree of relentless defense as a running bamboo, but regular pruning is important.
It’s easy to forget about a dwarf bamboo because it seems so small and innocuous. But the roots are always far more active than the visible vegetation will let on. One method of containment is to dig a trench around the area in which you’d like the bamboo to remain. This makes it easy to see when the roots are beginning to overreach their boundary.
With big clumpers like Oldham’s and Buddha Belly, the plant can occupy a pretty large foot print. If you don’t want something that’s going to spread 15 feet wide, you’ll need to plant a root barrier (see our article on bamboo containment) or else keep a vigilant schedule of pruning. Cutting back the new shoots as they slowly spread is usually enough to keep a clumping bamboo in check. (Note: This strategy does NOT work with running bamboos. Their roots will just continue to spread elsewhere, eventually pushing up new shoots wherever they can.)
If you found this article useful, please consider sharing it and subscribing to our mailing list. You might also enjoy some of the following blog posts.
- 10 Best bamboo varieties for your garden
- Growing bamboo: The complete how-to guide
- The best bamboo varieties for construction
- Bamboo containment
PHOTO CREDIT: A constellation of clumping bamboos at the Bambouseraie in southern France (photo by Pacha Hornaday)