David Coulson is a local certified Built Green design builder. He has a staff of 25 that have built throughout the Island for over 20 years.
How many times have you heard about bamboo taking over someone’s garden, lifting pavement or simply exploding into an invasive nightmare on the neighbour’s property?
I must admit I have seen the plant grow out of control on the Island, so I am here to share what I know in hopes it helps our neighbours and communities make good use of this incredible plant.
First of all, let me explain my passion for bamboo. In 1996, I attended the American Bamboo Association Conference gathering at the University of Hilo, Hawaii. We were side by side with the world’s top bamboo architects, landscape designers, and craftsmen in this unique material. From bamboo furniture and surfboards to 65-foot live plantings in children’s hospitals (+14% increased oxygen result here!) to the largest and heaviest constructed architectural rooflines on the planet. We ate bamboo, carved it, wove with it (guided by traditional Japanese gate builders) and studied it thanks to the masterful inspiration of David Farrelly, who published what remains the most comprehensive reference on bamboo, ‘The Book of Bamboo’. Look it up! Published by the Sierra Club.Farrelly’s book illustrates the 1500 plus varieties and 2500 plus traditional uses of bamboo practiced for centuries worldwide.That’s the scope of interest in this plant, and how I got my start with it.
Now, what we can do here on Vancouver Island with this monopodial (running) grass?Hard to imagine a grass in my yard now 3 inches (about 8 cm) in girth and 45 feet tall (14 meters) – but it’s there.The plant can grow as much as 2 feet per day here in June/July and provides me with an abundance of aesthetic and practical building products from fencing, curtain rods, ladders, beanpoles, roof-top picking poles, gutter brushes, plant and rose supports (see photo), occasional meal, plant pot, slingshot, garden stake, beer or water cup, railing spindles, garden feature, table frame and top, chair, bench and decorative window treatments to name a few.
I have 35 varieties of these runners all dug into a very heavy clay hill in Eagle Heights that in most gardening scenarios would not grow a ‘hill o beans’. I did have to supplement the soil to get the results I wanted, and of course I kept the bamboo patch separate from our other (flower, veggie, herb) garden plots.
So rule #1, plant in a secure area to keep contained. Options: – a large concrete lined box (best)- steel lined hole (still good but watch) or- container (risk overcrowding roots and drying out).
Containers will never provide the robust size and they are very hard to divide once established. Free running (need lots of room) is best as long as you keep the root or rhizome pruned back. And containers or barriers need only be 24 inches deep and ideally pitched at 7 degrees away from the plant.
Rule #2, water well but never make roots soggy or situate in low areas or they will rot. The Chinese called it ‘knit bone’ as its preferred home was the well-drained sides of fertile creeks and rivers. Through over-development, bamboo removal has now destabilized rivers and creeks in many countries, contributing to the fatal landslides we see annually.
Once well established, say after 7 years, a good patch of well-trained bamboo will start to yield it’s maximum size for the orientation and climate you have selected. I still get the odd surprise in years 8 to 10 with large culms (stalk or blade of bamboo grass) – they can be a trickster, keeping you on your toes. Like the one that suddenly appears 30 to 50 feet away one Spring indicating you have dropped your guard and they are truly ‘running’.
Year 7 is also the year one can start liberally thinning the clump by cutting out the older culms that now take on a slightly weathered colour indicating they have ‘hardened off’ and are at their best for use structurally (some varieties are destined for structural use, or for crafts, or fish poles, or weaving). Black bamboo (Phyllostachys negro) actually turns black with age as it starts off green for two to three years. But thinning out gives air to the plant and room to grow.Some bamboos can be cut earlier (years two and three) if you want the flexibility and bright colour for weaving, basketry, or simply for its clean and unaltered brilliance. Within a year of harvest, they mostly all fade to a buff yellow tan colour except for the revered black bamboo.And don’t forget, if you want a snack or lovely addition to your stir-fry, kick over a new shoot just as it’s breaking ground. Steam quickly and if at all bitter, add a bit of milk when cooking or just toss in the pan and enjoy. I often eat them raw on my late Spring rounds to see who’s coming up next. Rule #3, throughout the growing season here from late Spring to mid- Summer, feed with heavy nitrogen. Chicken manure and alfalfa powder are great to liberally feed at the base. Also, fun fact: bamboo loves pee. Your call.
After ten to 12 years of growing bamboo you start to get more aggressive with it.First, invest in a cordless Sawzall and buy some carbide-tipped, long cutting blades. Don’t spend too much as they dull quickly.Root (rhizome) prune the plants to where you want them to stop spreading, Rip the chunks of rhizome from the ground (often just inches below the surface) and plant directly and quickly into pots to propagate new plants. Watch for the small node that appears at the internodes (those wonderfully clear sections of bamboo) and looks like a brown polished fingernail-like growth. This is the life force that is deciding whether to be a new rhizome root OR an upward growing shoot and eventual culm. Keep moist in pot at all times, assuming they drain freely until you have three or four fresh new culms shooting up. This is best done in late fall or early spring. The new growth won’t show until Spring of course so Fall dividing gets the fibrous root structure going over Winter.This is a very serious grass and many have remarked that, together with the Eucalyptus tree, bamboo could provide enough fibre and construction material to look after the entire developing world.