Despite its woody exterior and pliable strength, bamboo is a member of the grass family. It is used for everything from building homes to brewing beer, but the most intriguing piece of the puzzle is how quickly it grows.
This woody grass fascinates researchers around the world; it is even reported that some species can double their size in a single day! Bamboo is quickly becoming one of the most important elements to the burgeoning green market. The regenerative nature of bamboo makes it more of a renewable and sustainable raw material than trees.
While bamboo can grow in just about any soil or climate, its most impressive growth rates require certain conditions. If grown in a slightly acidic soil with a healthy amount of water, and partial shade (during the hottest part of the day), bamboo can grow at about 2 inches per hour. On the slower side, most estimates place bamboo at about 24 inches in a single day. Considering that it’s slow pace, and it takes oak trees about 100-150 years to reach full maturity, there is no question that bamboo is a very fast maturing plant.
Bamboo only grows when sprouting, and will remain at the same height for the rest of the year. Large bamboo species are known to grow upwards of a foot a day, but the majority of standard bamboo species grow anywhere from half and inch to a few inches in a given day. The record for the fastest growth is 47.6 inches in a 24-hour period. Additionally, there are records of large tropical bamboo plants growing 100 feet in the span of merely three months!
Bamboo Growth Cycle
The first unique aspect of bamboo is that it can reach its full height and width in a single three-four month growing season. Trees and other woody materials cannot. The clumps of new shoots grow vertically in this first season, and do not branch out or flower.
In the second year, the outside pulp-like wall of each stem or “culm” becomes dry and hard. The individual nodes begin to sprout small branches and leaves. In the third year, the culm fully hardens, and the bamboo shoot is not considered fully mature.
In the standard life cycle of bamboo, fungus and mold begin to develop on the outer culm within the first five to seven years of its life. Within the decade, the fungus and mold will overtake the bamboo, causing it to collapse in on itself. For this reason, harvesting bamboo for construction, flooring, or furniture is best completed after full maturity at age 3, until about age 7, depending on the species.
All new growth of bamboo occurs during the wet season, so it is important not to disturb the clump of shoots during this time. Harvesting is best at the end of the dry season when sap levels are at their lowest, and damage to shoots is less likely.
Each individual culm goes through a 5-7 year life cycle, and is harvested from 2-3 years to 5-7 years of age. Daytime harvesting is generally recommended during dawn or dusk. Since photosynthesis is at its peak during the heat of the day, sap levels are highest, making harvesting more difficult. Some traditional bamboo growers watch the moon cycles and harvest during dawn or dusk on a waning moon.
Natural Death of Bamboo
The flowering of bamboo is a relatively rare occurrence, which results in the death of the bamboo plant shortly thereafter. The evolutionary reason and cause behind this is still unknown, but it seems that there comes a point when bamboo plants of the same stock flower and same age seem to focus all of their remaining energy into flowering, regardless of climate conditions or geographic location. These plants then die around the same time.
One theory states that simultaneous flowering increases the survival rate of their seeds. A subset of this theory goes so far as to claim that the lack of flowering has a way of regulating rodent predators, as they enter starvation during the period between flowering events.