Don’t hold your breath - this bamboo flowers every 120 years

OPINION Botanists the world over are mystified by a Chinese bamboo that flowers at long intervals.

Historians report that the Giant Chinese Timber Bamboo produced a huge crop of flowers in the year 919. It bloomed again in 1114, again about 1725, and again about 1845.

Phyllostachys bambusoides flowers at 120-year intervals, with very few flowers or none in between. Flowering must superstress the plants, for they die soon after.

Giant timber bamboo is perhaps the fastest growing plant on Earth, putting on nearly one meter a day to reach a height of 30 metres.

It is widely used for building decks, panels, flooring, scaffolding, furniture, blinds, spears, swords, bows and arrows, musical instruments, paper and so on.

Its shoots are cooked and eaten, used to make a condiment, or fermented to make an alcoholic drink. It is good for windbreaks and for controlling erosion.

Cuttings of these Chinese bamboos were long ago transplanted to Japan, Europe, Russia, the US and New Zealand, but none of them flowered spectacularly until the 1960s, when they all flowered in sync on different continents. Then they all died. Botanists find bamboo flowering has nothing to do with the weather or climate, and nothing to do with the quality of the soil or soil water. They think the plants have a mysterious clock or calendar built into their DNA.

More than 1000 bamboo species grow around the world. Some flower every year but others flower at 10-, 20- or 60-year intervals. At 120 years, Phyllostachys bambusoides has the longest flowering interval.

Long-term bamboo flowering has some disastrous consequences. A common bamboo in northern India seeds synchronously every 48 to 50 years, attracting tens of millions of rats. After eating all the bamboo seeds, the rats turn to grain crops, utterly ruining farmers and starving the local population. These famine years happen so regularly that the local community call them Bamboo Death Years.

The last Bamboo Death Year happened in 2006-8 and the Mizorami people are dreading the next famine some time between 2056 and 2060.

Some New Zealand nurseries specialise in growing and selling bamboos, offering about 12 species as ornamentals, others for fencing, erosion control, or as farm windbreaks. The Giant Chinese Timber Bamboo grows here, but it needs plenty of space as one plant can quickly grow to cover half an acre.

I amtold that bamboos were commonly used as windbreaks on many farms in Taranaki. Farmers there were amazed a few years ago when all their bamboos suddenly flowered and died, leaving them with no windbreaks. I tried to verify this story and would be pleased if any reader could put me right: bob.brockie@icloud.com

Anybody keen to swap bamboo stories might approach about 60 enthusiasts in the New Zealand Bamboo Society, whose aim is to promote the appreciation, growing and use of bamboo.

If Giant Chinese Timber Bamboo grows in your garden, don’t hold your breath for it to flower. You must wait until the year 2080.