The secret to bamboo’s fast growth
A bamboo grove
Bamboo shoots are known as a flavor of spring in Japan, but the period to enjoy their tender texture is fleeting as they quickly mature into full-grown bamboo. Why do the shoots grow so rapidly?
Shozo Shibata, president of Hyogo Prefectural Awaji Landscape Planning and Horticulture Academy and professor emeritus at Kyoto University, who specializes in bamboo ecology, explains, “They have a unique growth engine unlike any other plant.”
Bamboo shoots are the sprouts that emerge from the underground stems, or rhizomes, of bamboo. Once they break through the surface, their outer layers fall off, turning them into bamboo.
According to Shibata, the rapid growth occurs during the transition from bamboo shoot to bamboo. Common varieties in Japan, such as madake (Phyllostachys bambusoides) and moso bamboo (Phyllostachys edulis), have been reported to grow at a rate of around 120 centimeters in 24 hours, considered a world record among plants. This speedy growth was recorded by a researcher at Kyoto University, who announced the data in 1963.
This growth rate works out at about 5 centimeters per hour, “a speed visible to the naked eye,” Shibata notes. In just a few months, they can reach heights of 10 to 20 meters.
What allows them to grow so vigorously? The secret lies in the similarity of bamboo shoots’ structure to paper lanterns. The internal “folds” of a bamboo shoot become the nodes of the bamboo as it grows. “It’s like a folded paper lantern expanding and stretching out. Each node, akin to the rings of a paper lantern, has a ‘growth engine’ — a zone of active cell division that operates only during this phase,” Shibata explains.
If a bamboo plant had 50 nodes, for example, and each extended by 2 centimeters daily, the plant would grow 1 meter in a day.
Other plants have growth engines (growth points) only at the tips of roots and stems, but bamboo, being hollow, must grow uniformly in a circular fashion, otherwise it would end up bending.
As for the idiom “like bamboo shoots after the rain,” which describes things appearing one after another, does rain indeed promote bamboo shoot growth? Shibata provides insight.
“Bamboo shoots require a lot of energy for rapid growth. They store nutrients in their rhizomes from the previous year. Rain helps them utilize these nutrients, allowing them to grow quickly. We can say people’s observations in the past about ‘bamboo shoots after the rain’ are scientifically accurate,” Shibata concludes.
