Bamboo is one of the world’s fastest-growing members of the grass family. Unlike trees, bamboo does not grow wider or taller once its main stalk reaches its full size. The answer to whether it regrows after cutting depends entirely on which part of the plant is cut and the source of its energy reserves.
What Happens to the Cut Stalk (Culm)
The immediate answer to whether a cut stalk regrows is no. The above-ground stalk, called a culm, is a woody stem that lacks the ability to increase in diameter or height after its initial growth period. Once a culm is cut, it will remain at that exact height for the remainder of its life.
Bamboo growth is fundamentally different from a tree, which relies on secondary growth. Since the culm lacks a vascular cambium layer, it cannot heal or expand like a tree trunk. The cut portion will not sprout a new leader to regain its vertical size.
However, cutting the top of a culm does not necessarily kill it. The culm is still alive and its nodes below the cut may redirect energy to produce more lateral branches and leaves. This is often used to create a denser, bushier screen at a desired height, but the cane itself will never become taller than the cut point.
The Underground Engine: Rhizomes and New Growth
The life force of the bamboo plant resides beneath the soil in a network of underground stems called rhizomes. Rhizomes serve as the energy storage unit, holding starches and sugars that fuel all new growth.
When a culm is cut, the energy used to maintain that stalk is redirected back into the rhizome system. This stored energy is used to produce new shoots that emerge from the ground, often resulting in increased vigor and density in the following growing season.
Bamboo species are broadly categorized by their rhizome structure. Running bamboo (monopodial types) have rhizomes that grow horizontally, spreading rapidly and producing new culms over a wide area. Clumping bamboo (sympodial types) have short, thick rhizomes that grow more vertically, causing the culms to stay in a tight, concentrated cluster.
The type of rhizome dictates how quickly and widely new growth appears after a cutting disturbance. For both types, cutting above-ground growth prompts the underground network to generate replacement culms in the next growing cycle.
Cutting for Control: Pruning vs. Removal
Understanding the role of the rhizomes is important for managing a bamboo grove, as cutting the culms serves two different goals. Pruning for maintenance involves cutting older, damaged, or undesirable culms down to the ground. This stimulates the plant to produce new culms the following season, refreshing the grove.
Cutting the tops of culms, known as topping, is done for height control and to promote a denser canopy. The cut should be made just above a node to prevent a dead stub and encourage lateral branching.
Complete removal of bamboo requires targeting the rhizome system, as cutting only the culms will not succeed. The plant will continue to send up new shoots until the underground energy reserves are exhausted.
The most effective non-chemical removal involves repeated cutting of every new shoot as soon as it emerges. This process effectively starves the rhizomes of the ability to photosynthesize and replenish their stored energy.
For running bamboo, long-term control involves physically severing the rhizomes at the edge of the desired area, a process called root pruning. These underground stems typically grow in the top 2 to 5 inches of soil, making them accessible to a sharp spade for bi-annual maintenance.