In the world of ornamental horticulture, you can find some spectacular bamboo varieties that will make a great addition to your garden. But if you plant the wrong kind of bamboo, it can turn into an awful beast. And then you’ll never want to see another bamboo plant again. With around 1,500 types of bamboo to choose from, it’s helpful to know which are the most invasive varieties, so you can avoid them, and maintain a happy, healthy relationship with this noble family of grasses. Not to mention a friendly relationship with your next door neighbors.
Not all varieties of bamboo spread so vigorously, but some species can certainly be invasive. The most invasive varieties belong to the genus Phyllostachys. These temperate bamboos, native to East Asia, have running rhizomes that can spread indefinitely. Other aggressive, running bamboo genera include Sasa and Pleioblastus, but they tend to grow much smaller. Most tropical bamboos, like genus Bambusa and Dendrocalamus, have clumping rhizomes, meaning that their roots and shoots cling closer together, usually spreading to a limited size.
This is such a concern that some states and cities and gone so far as to pass laws that regulate or prohibit certain kinds of bamboo. Although in reality, the invasive nature of bamboo has been greatly exaggerated in popular culture.
To begin with, here’s a quick chart that identifies some of the most invasive types of running bamboo.
|Botanical name||Common name||Description|
|Phyllostachys aurea||Golden bamboo||Tall (30′) and slender (less than 1″) culms with dense green foliage|
|Phyllostachys aureosulcata||Yellow groove bamboo||Large timber bamboo (50′ tall, 2-3″ thick) with yellow stripe|
|Phyllostachys bissetii||Bissetii||Very cold hardy, 10-30′ tall, with thick foliage|
|Phyllostachys rubromarginata||Red margin bamboo||Ideal for privacy screens, up to 40′ tall and 3″ in diameter|
Runners and clumpers
How they grow
The first thing to understand is that you can basically divide bamboo into two different categories: running bamboo and clumping bamboo. As you might guess from the name, running bamboo can spread quickly and cover great areas, basically running amok. These are the varieties you need to be careful with. But not all varieties of running bamboo are created equal. Some species are especially aggressive and invasive, and those are the ones we want to warn you about.
Clumping bamboos, by contrast, tend to stay put. They have a different type of root system that remains tight and compact. Generally, each species of clumping bamboo has its maximum footprint. In other words, once the grove reaches full size, which could be anywhere from a few feet to several yards in diameter, it will stop spreading. There are hundreds of kinds of clumping bamboo, including some very popular and attractive varieties like Oldhammi and Buddha’s Belly, of the genus Bambusa.
Even some kinds of clumping bamboo can get out of control if they are left to their own devices. While most clumps will reach maximum size and then stop spreading, there are also open-clump species which will continue to spread over time, albeit slowly.
Where they grow
Generally speaking, running bamboos and clumping bamboos prefer different types of climates. This is not a hard and fast rule, but it is an important distinction to be aware of. Most of the clumping bamboos are native to tropical and subtropical climates like South East Asian and Indonesia. This makes many of those varieties difficult to grow in most parts of Europe and North America. But again, there are a number of exceptions.
If you live in a cooler, more moderate climate, you’ll probably have better luck growing running bamboo, which is typically native to temperate climates like central and southern China. These varieties are going to be a lot hardier in the winter, able to tolerate freezing temperatures for longer periods of time. This makes running bamboo more popular in many parts of the U.S.
How running bamboo becomes a problem
The problem is, once a running bamboo gets going, it can be almost impossible to stop. Usually someone will start out with a couple pots and gloat over how well they are growing. But when the spreading doesn’t stop, the bamboo easily becomes a nuisance.
There’s an old saying about bamboo: The first year it sleeps, the second year it creeps, and the third year it leaps. The point is that you might not notice anything out of the ordinary in the first year or two of growing bamboo. But underground, the vigorous rhizome root system is gaining a foothold. And once the foundation is in place, that’s when you really see the new shoots coming up around the yard.
If not well contained, the bamboo shoots could show up in your flower beds, your vegetable patch, or your well-manicured lawn. Not only that, but they have no respect for property lines. Bamboo frequently crawls under fences and wreaks havoc on other people’s gardens. This is not a good way to keep on good terms with your neighbors.
Notorious runners to watch out for
There are hundreds of varieties of running bamboo out there, but many of the most aggressive species belong to the genus Phyllostachys.
- Phyllostachys aurea (Golden bamboo or Fishpole bamboo): An attractive, fast-growing species that gets up to 30 feet tall with thick culms and dense green foliage, Golden Bamboo has become a very popular variety. It’s especially popular for privacy screens on account of its height and density. It’s actually a great choice in cold climates where it’s less likely to spread out of control. But beware, with ample water and mild winters, it can spread like crazy. (Not to be confused with Bambusa vulgaris, an open-clump variety of timber bamboo which is also known as Golden Bamboo.)
- Phyllostachys aureosulcata (Yellow groove bamboo): Widely grown as an ornamental, this species has a distinctive yellow stripe that runs along the culm grooves. Shoots can grow up to 50 feet tall and 2-3 inches in diameter. The fresh shoots are also known to be quite tasty. Some New England states have banned this species, which is cold hardy and invasive.
- Phyllostachys bissetii: Very cold hardy with a vigorous growth habit, Bissetii is a popular choice for privacy screens. In the coldest parts of the country, it usually gets about 10 feet tall. In more moderate areas, like USDA zone 7, it can exceed 30 feet in height with an aggressive root system.
- Phyllostachys rubromarginata: Another popular choice for privacy screens, because it fills in so quickly. It’s not quite a timber bamboo, but it’s larger than most, with culms up to 30-40′ tall and 3″ thick. A reddish hue on the new shoots has earned it the nickname Red margin bamboo.
Have you run into another extremely invasive species of bamboo that we overlooked? Please let us know about it in the comments section!
Recognizing and identifying running bamboo
A tricky thing about bamboo is that it comes in over a thousand varieties, many of which look extremely similar, almost indistinguishable to the untrained eye. In fact, it’s not uncommon for nurseries to mislabel their bamboo. (That’s why we always recommend finding a nursery that specializes in bamboo.) There can be a lot of confusion with the common names, such as Golden Bamboo, which could actually refer to a few different species. Then there’s names like Timber Bamboo, which doesn’t tell you anything about the species, only that it gets real big.
But there is a way to identify Phyllostachys, which is the largest genus of running bamboo, including dozens of species. If you look closely at the stems (culms) of a Phyllostachys bamboo, you’ll see a groove that runs lengthwise between the nodes. The groves alternate sides, from one internode to the next. It’s a distinctive characteristic, and you’ve probably noticed it before, because Phyllostachys are so common and prolific.
If you see this groove, you can be sure that you’re dealing with a running bamboo. And for a novice, that’s a pretty good start. It won’t tell you if it’s a super aggressive runner, but you’ll know that it’s a runner. Unfortunately, if you don’t see the groove, you can’t be certain that it’s a clumping bamboo. You’re only pretty sure it’s not a Phyllostachys. Yeah, nobody said this would be easy.
Why do people plant running bamboo?
Though it may sound like madness to anyone who has ever been sued by their neighbor or had to pay a few thousand dollars to remove a running bamboo grove, there are actually a few reasons people might choose to plant a running variety.
- Fast growing: Sometimes you just want to plant something that will fill an area quickly, without waiting 2 or 3 years. This is often the case with a privacy hedge, for example.
- Cold hardy: In general, running bamboos can better tolerate cold weather and deep freezes in the winter.
- Inexpensive: Runners are less expensive at the nursery, because they propagate so easily. But a big price could come later on if the bamboo invades your neighbor’s antique rose garden or tears up an underground utility line.
- Attractive species: Some of the very attractive and desirable bamboo species happen to be runners, like Black Bamboo (Phyllostachys nigra).
Control your bamboo
Because of its invasive potential, some cities and homeowner’s associations actually have laws and regulations against planting bamboo. For the safety of your garden and your neighbors, we always recommending using a root barrier when planting a running bamboo species.
Bamboo Shield makes an excellent root barrier product. The barrier, available from Amazon, comes in three sizes, for cold warm and tropical climates. The warmer the climate, the thicker the barrier.
If you found this article on invasive bamboos helpful, please consider subscribing to our blog. You might also enjoy some of these other articles.
- Introducing bamboo: Genus by genus
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- Tips for bamboo containment and removal
- 15 Varieties of Cold Hardy Bamboo
- Proverbs about bamboo
- Pros and Cons of Potted Bamboo
- Great bamboo nurseries of America
FEATURED PHOTO: A beast among the ferocious bamboo grass (Unsplash)