True bamboo, a giant grass, cannot survive fully submerged in water. This inability stems from its fundamental biology as a terrestrial plant, which lacks the specialized structures necessary to acquire oxygen once its root system is underwater. The common confusion arises because the plant typically grown in water and referred to as “bamboo” is not actually a member of the bamboo family.
Distinguishing True Bamboo from Aquatic Look-Alikes
True bamboo belongs to the grass family Poaceae, specifically the subfamily Bambusoideae, and includes thousands of species like Moso and timber bamboo. These woody perennial grasses are terrestrial plants that naturally thrive in well-drained soil, requiring access to atmospheric oxygen through the soil.
The plant commonly cultivated in vases of water is Dracaena sanderiana, often marketed as “Lucky Bamboo.” This plant is not a grass; it belongs to the Asparagaceae family, making it more closely related to asparagus than to true bamboo. The resemblance is superficial, primarily due to its slender, segmented stem structure.
Other plants, such as horsetail rush, are sometimes mistaken for bamboo because of their jointed stems. Dracaena sanderiana is the primary source of the belief that bamboo can grow indefinitely in water because it is an adaptable houseplant. This plant can survive in a soil-less, water-based culture for extended periods, requiring only its roots and a small portion of its stem to be submerged to draw water and nutrients.
Why True Bamboo Cannot Survive Submerged
The physiological reason true bamboo cannot be submerged relates directly to the oxygen requirements of its roots. Like most terrestrial plants, bamboo roots undergo aerobic respiration, a process that requires a steady supply of oxygen to generate energy for growth and nutrient uptake. Soil naturally contains air pockets that supply this oxygen.
When a terrestrial plant’s roots are fully submerged, water fills the air pockets. The oxygen diffusion rate in water is significantly slower than in air, dropping to about one ten-thousandth of the rate. This lack of oxygen creates an anoxic (zero oxygen) or severely hypoxic (low oxygen) environment. Without sufficient oxygen, the roots cannot perform aerobic respiration and begin to suffocate, leading to cell death and rot.
Aquatic plants and flood-tolerant species have specialized tissue called aerenchyma, which forms air channels to transport oxygen from the leaves down to the submerged tissues. True bamboo does not possess these extensive gas-transporting structures, making it highly susceptible to waterlogging. The hollow nature of the bamboo culm (stem) is not sufficient to transport the necessary oxygen to the underground root and rhizome system to prevent metabolic failure.
Caring for Bamboo-Like Plants in Water
Caring for water-grown Dracaena sanderiana requires attention to water quality and freshness. The plant is sensitive to chemicals found in municipal water supplies, so using filtered, distilled, or rainwater is preferred. If tap water must be used, allow it to sit in an open container for at least 24 hours to allow chlorine to dissipate. This process will not remove fluoride, which can cause leaf tips to turn brown.
The water level only needs to cover the roots and the bottom inch or two of the stalk, as completely submerging the entire stalk can still lead to rot. Changing the water completely every one to two weeks is necessary to replenish dissolved oxygen and prevent the growth of algae or bacteria. Stagnant water quickly becomes oxygen-depleted, creating a stressful environment.
Since water does not contain the same mineral content as soil, Dracaena sanderiana benefits from minimal nutrient supplementation. A diluted liquid fertilizer, often at about one-tenth the recommended strength, can be applied every month or two during active growth periods. The plant thrives best in bright, indirect light, which mimics its natural understory habitat. Direct sunlight should be avoided because it can scorch the leaves and promote algae growth in the water container.