Bamboo is a fast-growing plant belonging to the grass family. The question of its invasiveness depends entirely on the specific variety planted. Certain types are highly aggressive and can rapidly spread across a property, creating significant management issues. Other varieties are well-behaved, remaining neatly contained. Understanding the biological differences between these two categories is necessary to make an informed choice for your landscape.
The Core Distinction: Running vs. Clumping Growth
The difference in growth habits stems from the structure of the plant’s underground stems, known as rhizomes. Bamboo is categorized into two main types based on these rhizomes: running and clumping. Running bamboos are defined by their monopodial rhizome system, which is the source of the plant’s aggressive reputation.
Running rhizomes are long, thin, and branch extensively, allowing them to spread horizontally away from the main plant. Common running varieties belong to the genus Phyllostachys, which includes types like Golden Bamboo.
Clumping varieties utilize a sympodial rhizome system. These rhizomes are short and thick, naturally curving upward to produce new canes very close to the parent plant. This growth pattern results in a tight, contained cluster that expands slowly outward over many years. Genera such as Fargesia and many Bambusa species exhibit this non-aggressive clumping behavior.
Understanding Aggressive Spreading
The aggressive spreading seen in running bamboo is a direct result of its specialized subterranean anatomy. Monopodial rhizomes function like lateral runners, rapidly extending a network of underground stems and buds. These rhizomes typically grow within the top 12 to 18 inches of soil, allowing them to travel considerable distances unchecked.
In a single growing season, the rhizomes of some aggressive species can extend 10 to 20 feet away from the original planting. This rapid, unpredictable expansion makes running bamboo difficult to manage once established. The dense network of rhizomes can easily cross property lines and emerge in lawns, garden beds, or crack through weak pavement.
Removing an established running bamboo stand is challenging because of this extensive underground system. Every segment of rhizome left in the ground has the potential to sprout a new cane, requiring persistent monitoring and removal.
Control and Containment Strategies
Managing the spread of running bamboo requires proactive containment strategies. The most reliable method to prevent unwanted expansion is the installation of a physical rhizome barrier made of a non-degradable, durable material, such as High-Density Polyethylene (HDPE).
The barrier material should have a thickness of at least 60 mil, though 80 mil is recommended for aggressive species or plantings near sensitive structures. The barrier must be installed in a vertical trench 24 to 30 inches deep, ensuring it is deeper than the rhizomes typically travel. To prevent runners from growing up and over the obstruction, the barrier must protrude approximately two inches above the soil line.
If a physical barrier is not feasible, annual root pruning is a necessary maintenance task. This involves digging a shallow trench around the perimeter each spring and cutting any outward-growing rhizomes with a sharp spade. This practice severs the connection to the parent plant, preventing new growth from establishing outside the boundary.
For complete eradication, the process is labor-intensive. The entire root ball and all attached rhizomes must be meticulously dug out of the ground. Alternatively, continually removing every new shoot, or culm, as it emerges above ground will eventually starve the underground rhizome system. Chemical herbicides should only be considered as a last resort and often require repeated applications.
Selecting Non-Aggressive Varieties
For gardeners who want the aesthetic appeal of bamboo without the risk of aggressive spreading, selecting clumping varieties is the non-invasive option. These species do not require a rhizome barrier or the extensive maintenance necessary for running bamboo. The Fargesia genus, native to the mountains of China, is the most popular choice for temperate climates due to its exceptional cold-hardiness.
Fargesia species, such as F. nitida (Blue Fountain Bamboo) and F. murieliae (Umbrella Bamboo), are non-spreading and tolerate temperatures as low as negative 20°F. These clumpers expand slowly, typically only 2 to 12 inches in diameter per year, forming dense, upright screens. Their low-maintenance nature and suitability for container planting make them ideal for smaller yards or privacy screens.
In warmer, subtropical climates, many species from the Bambusa genus are excellent clumping alternatives. Varieties like Bambusa multiplex (Hedge Bamboo) and Bambusa textilis (Weavers Bamboo) offer rapid vertical growth without the horizontal spread. Focusing on species with a sympodial root structure allows property owners to enjoy the beauty of bamboo without the worry of invasive takeover.