World Bamboo Day is observed on September 18 to raise awareness about bamboo. Bamboo is a fast-growing grass, and some species can grow up to 36 inches (91 cm) in 24 hours. There are over 1,500 species worldwide, used in construction, furniture, food and musical instruments. The day was declared on September 18, 2009, at the 8th World Bamboo Congress in Bangkok, Thailand, and coincides with Royal Thai Forestry Day. The 2026 theme is “Bamboo Beyond Borders”.