Aggressive bamboo growth stems from its vigorous underground root network, known as rhizomes. These specialized stems allow the plant to colonize new areas rapidly, making containment a serious challenge for property owners. Stopping this invasive spread requires a clear understanding of the plant’s biology and a long-term commitment to management. Effective control depends on applying the correct technique, tailored to the specific situation and the plant’s current growth stage. Addressing the problem early is far more manageable than attempting to reclaim a fully established stand.
Understanding the Types of Bamboo
The first step in effective management is identifying the type of bamboo present, as control methods differ significantly between the two main categories. Running bamboo, which includes species like Phyllostachys, utilizes long, slender rhizomes known as leptomorphs. These underground stems extend horizontally, often traveling several feet away from the parent plant before sending up new shoots, leading to the widespread invasion of property lines and gardens.
Clumping bamboo, such as Fargesia species, exhibits a much more contained growth pattern due to its short, U-shaped pachymorph rhizomes. New culms emerge close to the original plant, resulting in a slowly expanding clump rather than a wide-ranging spread. Because of its invasive nature, running bamboo is the primary subject of aggressive containment and control strategies.
Installing Physical Root Barriers
A highly effective preventative measure against running bamboo is installing a specialized physical root barrier. The material must be non-degradable and robust, typically high-density polyethylene (HDPE) or non-corrosive sheet metal, with a minimum thickness of 60 mil. Standard plastic sheeting or landscape fabric will not withstand the pressure and sharp tips of the growing rhizomes.
The barrier must be installed 24 to 30 inches deep to prevent rhizomes from tunneling underneath. Angle the barrier slightly, about 10 to 15 degrees outward from the clump, to deflect upward-growing rhizomes toward the surface for monitoring and pruning. Crucially, the barrier must protrude 2 to 3 inches above the soil grade.
This above-ground lip prevents rhizomes, which often grow just below the surface, from growing over the top and continuing their spread. If the containment area requires multiple pieces, the seams must be overlapped significantly and securely sealed using specialized joining materials.
A failure point at a seam can render the entire installation useless, as the bamboo will exploit any gap to escape. Regular inspection of the barrier’s perimeter is necessary to ensure no rhizomes have found a way around or over the material.
Ongoing Manual Control Techniques
Even with a physical barrier in place, ongoing manual control is necessary to manage aggressive growth. Rhizome pruning, or trenching, involves digging a shallow trench around the perimeter of the stand. This trench, about 6 to 8 inches deep, exposes and severs any new rhizomes attempting to spread beyond the desired area. This maintenance should be performed at least twice a year, typically in the late spring and early fall, when rhizome growth is most active.
Immediately cutting new shoots, known as culms, as they emerge from the ground is another control method. Consistently cutting these new shoots at ground level significantly reduces the plant’s photosynthetic capacity. Repeatedly removing these growth points forces the underground root system to deplete its stored energy reserves without the ability to replenish them.
For aggressive varieties or where a permanent in-ground barrier is impractical, container gardening provides a manageable containment strategy. The bamboo is planted in a large, sturdy container, often placed above ground or slightly submerged. The container must be routinely checked and root-pruned to prevent the bamboo from becoming root-bound or growing through drainage holes into the surrounding soil.
Complete Eradication Methods
Complete eradication is required when a bamboo stand is unwanted, representing a major undertaking due to the plant’s robust underground structure. The most immediate method is mechanical removal, which involves manually digging up the entire root mass and rhizome network. This process is labor-intensive and requires the removal of all root fragments, as even small pieces of rhizome can sprout into new plants. Excavation equipment is often necessary for large or deeply established stands.
A less physically taxing, yet time-consuming, approach is the “cut and starve” method, which relies on exhausting the plant’s energy reserves. This technique requires repeatedly cutting down every culm at ground level as soon as it emerges. This process must be maintained consistently over several growing seasons, often taking two to three years, to starve the extensive root system. Only once new shoots cease to appear can the remaining root material be considered dead.
For established stands resistant to manual methods, chemical control using systemic herbicides, such as glyphosate, may be necessary. The most effective application involves cutting the culms and immediately applying the concentrated herbicide directly to the fresh cut surface. This ensures the chemical is quickly translocated down into the rhizome system to kill the entire root mass.
Alternatively, the herbicide can be applied to the leaves of freshly mowed or severely cut-back foliage, though this method is less targeted. Follow all manufacturer instructions and local regulations when using herbicides. Chemical application is typically considered a last resort after extensive manual and mechanical attempts have failed.