Golden Bamboo, botanically known as Phyllostachys aurea, is a highly sought-after ornamental grass prized for its upright, woody stems, called culms, which mature from green to a distinct golden yellow color. Gardeners frequently choose this species for privacy screens or as an architectural accent plant in a variety of landscapes. Understanding how the plant spreads is the homeowner’s primary concern, as its specific growth habit determines its long-term impact on the garden’s layout and maintenance needs.
Golden Bamboo’s Growth Habit Classification
Golden Bamboo (Phyllostachys aurea) is unequivocally classified as a running bamboo species. This means it has an aggressive growth pattern that spreads laterally away from the original planting location. The scientific reason for this behavior is its specific type of underground stem, or rhizome, which is morphologically termed leptomorph. The entire genus Phyllostachys is characterized by this rhizome structure, confirming its inherent tendency to spread widely across a landscape if left unmanaged.
The Difference Between Running and Clumping Bamboo
The fundamental difference between bamboo growth habits lies in the morphology of its rhizome system. Running bamboos utilize a leptomorph rhizome, which is long, slender, and characterized by extensive horizontal growth. These rhizomes spread aggressively, sometimes traveling several feet in a single season, producing new culms at distant lateral buds.
Conversely, clumping bamboos develop a pachymorph rhizome, which is short, thick, and curved. This compact structure causes new culms to emerge immediately next to the existing plant, resulting in a tight, non-invasive cluster that expands slowly. The pachymorph rhizome’s apical bud turns upward to become the new culm, which prevents wide lateral movement and maintains the plant’s defined footprint.
Specific Traits That Lead to Golden Bamboo Confusion
Confusion regarding Golden Bamboo’s classification arises from two traits that visually contradict its running nature. The most distinctive characteristic is the compression of internodes, which frequently occurs at the base of the culm. This visual “stacking” gives the lower cane a dense, swollen, or tortoise-shell appearance that mimics the tight growth pattern of a clumping variety.
This compressed growth is a natural feature of P. aurea and is a key identification trait, especially in plants grown in containers or under environmental stress. Additionally, the species exhibits variable behavior based on climate and soil conditions. In cold regions or poor, dry soils, the vigor of its leptomorph rhizomes is suppressed, causing the plant to spread much more slowly and form a tighter grove. Despite these visual effects or climate-induced slowness, the underground rhizome system of P. aurea remains genetically a running type, retaining the potential for rapid spread if conditions improve.
Controlling the Spread of Running Bamboo
Containing Golden Bamboo requires proactive management focused on blocking or removing its aggressive leptomorph rhizomes. The most effective long-term method is installing a physical rhizome barrier. This barrier should be made of a thick, non-porous material, such as 60 to 80-mil high-density polyethylene (HDPE) plastic.
For proper containment, the barrier must be buried vertically around the planting area to a depth of 24 to 30 inches. It is important for the barrier to extend approximately two inches above the soil surface to prevent rhizomes from growing over the edge. A necessary complement is an annual ‘root patrol,’ which involves cutting and removing any escaping rhizomes. This is best done by slicing the perimeter with a sharp spade during the spring shooting season when new growth is most active and visible.