We are witness to an unusual phenomenon in Caldwell County: the mass flowering and subsequent die-off of bamboo. This has sparked curiosity and concern, especially considering bamboo’s reputation as a vigorous and often invasive plant. The bamboo flowering and die-off is happening in pockets of Caldwell County and along Hwy 268 through Happy Valley and into Wilkes County.

The Lifecycle of Bamboo

Bamboo, a member of the grass family Poaceae, is known for its rapid growth and ability to spread quickly. Its resilience and aggressive growth make it challenging to control.

However, bamboo has a secretive and less known aspect to its lifecycle – its flowering pattern. Unlike most plants that flower annually, bamboo species exhibit a unique flowering cycle that can span decades. This phenomenon is known as gregarious or synchronous flowering, where bamboo plants of the same species bloom simultaneously across a large region. Depending on the species, these cycles can range from 3 years to 150 years.

Close up image of bamboo inflorescence. This is where the seeds develop after flowering. (photo credit: Seth Nagy)

Bamboo relies on wind for pollination. Many flowers need to open at the same time so there is enough pollen in the environment for successful pollination. After flowering, the parent plant typically dies to give their seedlings the water, nutrients, space, and sunlight to grow. The dead bamboo plants create a nurturing mulch in which the new seedlings can grow. However, what triggers this gregarious flowering pattern is still a mystery.

The Impact of Flowering

When bamboo flowers, it undergoes a significant transformation. The plant allocates a tremendous amount of stored energy from its root system to produce flowers and seeds. This often leads to the death of the plant. This mass die-off can leave entire bamboo groves looking dead or lifeless.

Aerial image of bamboo that has flowered and died in Gamewell. (photo credit: Seth Nagy)

For many, the sight of dead bamboo might seem like a welcomed reprieve from an otherwise invasive species. However, this die-off is a natural part of bamboo’s lifecycle and has been occurring for centuries.

Regeneration, Recovery, or Control?

Despite the initial die-off, bamboo has remarkable regenerative capabilities. The flowers produce seeds, which, given the right conditions, can germinate and grow into new bamboo plants. Additionally, some bamboo rhizomes (root system) may recover.

If eradicating bamboo is the goal, then clearing the site after flowering is my suggestion. While bamboo is in this weakened state, it will be much easier to control. Mowing or targeted herbicide applications will be able to control seedling bamboo. However, removing the overburden of dead bamboo culms will make control easier and more practical. For large sites, a forestry mulcher might be the best choice.

A Natural Curiosity

Mass flowering of bamboo is a rare and intriguing event that reminds us of the complexity and wonder of the natural world. While bamboo’s aggressive growth can be a challenge, its lifecycle, including the flowering and regeneration process, is a testament to its resilience and adaptability.

To take advantage of this opportunity in Caldwell County, Dr. Alexander Krings, Professor & Director of the Vascular Plant Herbarium at NC State University, will be collecting samples. Physical samples are the best way to accurately identify plants. The lack of comprehensive taxonomic studies of bamboo makes identification a challenge. In 2022, Johnston County (North Carolina) had a species of bamboo that flowered. Samples were collected from Johnston County. It will be interesting if we have the same species now flowering in Caldwell County.

Bamboo is most abundant in Asia and South America, but there are native species in Africa, Australia, Central America, and North America. In North Carolina, the native bamboo genus is Arundinaria. These native species are not as dense or tall as invasive species. It is thought there were many native bamboo species in North America, but the last ice age left us with only three surviving native species today.

Bamboo as a Forage

Bamboo is a forage source for many animals around the world. The most well-known are giant panda bears. They are native to China and forage almost exclusively on bamboo. However, Gaur or the Indian bison, Asian elephant, and Red panda also feed on bamboo. The leaves are high in protein. A sample from Burke County sent to the NC Department of Agriculture Forage Lab tested 19% crude protein, and another sample sent to Cornell’s Dairy One lab tested 18% crude protein. Energy in the samples was both in the mid 50’s for Total Digestible Nutrients (TDN), which is similar to low-quality fescue hay. Cattle, horses, and goats will all readily graze on bamboo leaves if within reach.

Seeking Answers and Assistance

Bamboo’s flowering and subsequent die-off are natural phenomena that offer a unique opportunity for landowners. Now is a time to either control bamboo or nurture it back to its full glory.

Jason Noble, County Forest Ranger, examining a stand of flowering bamboo in Caldwell County. (photo credit: Seth Nagy)

If you have bamboo that has flowered, let us know. We’d like to track where this is occurring in Caldwell County. As always, if you have agriculture or horticulture questions, call the N.C. Cooperative Extension, Caldwell County Center at 828-757-1290.