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It all sounds like a poem, or a metaphor, or a dream: Black bamboo blooms once every 120 years. All of it around the world blooms at the same time. Then, it all dies, and the cycle begins again.
The big event is happening right now in Southeast Portland at Leach Botanical Garden’s grove of black bamboo (scientific name Phyllostachys nigra). It started flowering about two months ago, according to Adam Hart, Leach’s horticulture director, and he doesn’t know exactly how long the bloom will last—its life cycle is difficult to study since the last time this happened was around 1906.
“It’s all a bit of a mystery,” Hart says.
Bamboo is a type of grass, so don’t expect bright, traditional flowers covering the stalks. Instead, the bloom looks more like that of corn or wheat, which are also both grasses, botanically speaking. Think light yellow, corn-like seeds and shoots.
The Leaches planted the black bamboo near their house in the 1930s or ‘40s when they were building the garden, Hart says. The family left the 17-acre property to Portland Parks & Recreation in 1972.
There are a lot of unknowns in the horticultural community about Phyllostachys nigra. Some report that its lifespan is 40 or 80 years, though most agree it’s 120. How does all the black bamboo worldwide coordinate its bloom, and how does the plant’s internal clock tell them it’s go-time? Also, if the plant dies after it blooms, how does it reproduce and survive?
Hart will be doing hands-on research at Leach Botanical Garden to figure out that last part. He plans to collect and germinate the seeds, though everything he’s reading says they won’t be viable. He also will try to get it to re-grow from its underground roots, which he assumes will not die.
The bamboo is by the front door of the Manor House, which is found by walking straight on the first path after entering the garden and heading down the hill. There might not be a ton of time left to see the black bamboo in bloom, though, Hart says.
“I’m seeing a lot of leaves falling off the plant, and that is making me think it’s likely already declining from the energy its putting into flowering,” he says. “I think it will be done fairly soon.”
Next bloom: 2146.
GO: Leach Botanical Garden, 12323 SE Claybourne St. 503-208-6030, leachgarden.org. 10 am-4 pm Thursday-Sunday. $12.
