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The Globe and Mail
By Ian Brown, The Globe and Mail Published Wednesday, February 24, 2010

Green fields and beehives that span the Vancouver Convention Centre's roof have the whole city abuzz

Cutting eight acres of lawn 12 storeys in the air takes three men 10 days of damn hard work. The good news if you're trimming the grass that blankets the roof of the Vancouver Convention Centre - the angled patch of aerial greensward showing up all over the world on TV while the building doubles as the Olympic broadcasting centre - is that you only have to do it once a year.

That would be in October. The last time they clipped the fringe - which was also the first time, given that the building was the largest non-industrial living roof in North America isn't even a year old - it was three feet high.

The only other difficulty the mowers had was the bees. "You can see they get a little agitated when we get too close," says Reese Rhem, the green roof's planting supervisor, and the man in charge of mowing.

Oh, right, the bees. This is Vancouver: It is not enough that the lid of the building is a sky-high lawn the size of 5.8 football fields (or the equivalent of 402 studio apartments of 650 square feet each just down the way in fancy Coal Harbour, which rent for $2,800 a month in this real-estate-mad city). No. There have to be a quarter of a million bees on the roof as well.

The roof looks like a green and pleasant coastal grassland up there in the air, which is what it actually is, by design - the ultimate village green in a city that wants to be a global model for an environmentally conscious future, and that chose these Winter Games to be its showcase.

Green roofs have sprouted in Vancouver for 30 years. But there are green roofs, and there are freaking huge green roofs. This is one of the latter. The convention centre, a landform building that conforms to its surrounding topography has an 80,000-square-foot ballroom with no supporting pillars: A standard intensive green roof would bring the ceiling down.

To avoid that, Bruce Hemstock, the landscape architect whose firm, PWL Partnership, created the roof, was forced to design a growing medium no heavier than "about 39.6 pounds per square foot." Mr. Hemstock is the kind of person who uses a qualifier such as "about 39.6." He's proud of his growing medium, consisting as it does of entirely repurposed parts: Fraser River silt that had to be dredged anyway, composted organic material (wood pulp and kitchen scraps from Vancouver's restaurants) and lava rock (structure without weight).

It has no peat moss," Mr. Hemstock says. "That's important, because peat moss is the lungs of the earth, and we didn't want to use any."

Into his mix he added 400,000 plant plugs (common thrift, Douglas asters, a fistful of sedges, for starters); 128 kilograms of seed (25 different species of native grasses and herbs, including pearly everlast and poppies and California blue-eyed grass, which sounds like the start of a wild night); and 80,000 bulbs (among them common camas and Hooker's onion, which sound like the potential consequence of same).

The misture retains 35 percent of the roof's annual metres in rain, preventing it from draining into city sewers; hooked up in turn to a toilet-water cleansing system, the roof has helped reduce the building's potable water needs by nearly 73 per cent.

When the grass hit a metre last October, Reece Rehm hired a sickle mower, a custom-made, self-propelling, one-man industrial scything machine - you won't be buying one at your official Olympic Rona outlet, good buddy. He added a brace of brush-cutters, "which are essentially industrial weed-whackers, for the edges and the slopes." The edges can be tricky given that they run alongside as much as a 12 storey drop to the hard pavement and water below. This may be the only lawn job on earth where the gardeners wear safety harnesses.

"The grass is so tall and thick," Mr. Rehm says, "and the area is so big, that an ordinary mower couldn't handle it." The first go took three staged whacks. "The hardest part is probably the steep slopes," which can run between 13 and 53 degrees. "It was very laborious." He plans to use a bigger crew next October. Weeding alone needs two full-time students pulling clover on their hands and knees every day of the summer, Mr. Rehm, like Mr. Hemstock, has to go up on the roof regularly. But he speaks for both of them when he says, "Oh. I love it up there. Every time I go, I have a sense of accomplishment. It's the biggest thing I've ever worked on."

The roof (which can be visited by the public only on its western end; the rest is insect and bird habitat) can be seen in the background of a Super Natural British Columbia television ad that stars basketballer Steve Nash. (These Olympics are a lot of things, and one of them is a gigantic tourism spot.)

Allan Garr, the green roof's beekeeper, a former labour and economics specialist for the CBC (why does that make perfect sense?), arrived in Vancouver 15 years ago. "I became involved in beekeeping, which was illegal. It was a little like having a grow op." Thanks to Mr. Garr's tireless efforts, Vancouver (unlike Toronto) now has intelligent bee laws: City dwellers here can have two hives in their backyards (you can even have one on the balcony of an apartment in Paris) as long as they erect a six-foot fence. "Bees are little like airplanes," Mr. Garr says. They need a flight path. You don't want them bumping into your neighbour's head, so if you put up a six-foot fence, they get up high enough."

But downtown bees were another story. The all-powerful Vancouver Olympic Committee originally wanted the green roof's four hives removed for the Games. But Mr. Garr Prevailed: He is now the only person allowed on the roof of the annually bureaucratic broadcast centre. (He has already relocated hives at Vancouver's public science centre because the Russian Olympic delegation took it over and renamed it Sochi House for the duration.)

Mr. Garr's bees caused another brief pollen-up with the developers of the nearby, brand-new Pacific Fairmont Hotel and condo tower ($2-million each) that opened two days before the Games and sports a line of poetry written in steel on its sides: lying on top of a building the clouds looked no nearer than when I was lying on the street...

Mr. Garr assured the owners irritated bees would not swarm the guests. After all, bees can't read.

Instead, last year, the greenroof bees produced fifty pounds of honey, and Mr. Garr expects 225 pounds now that they're settled. Perhaps a contest to brand it? My Rooftop Honey? The mind buzzes.

The real purpose of the green roof hives, however, is educational - to "bring nature back to the city," Mr. Garr says. A third of North America's diet is made up of plants requiring pollination, and bees pollinate 80 per cent of those crops. With colony collapse disorder still afflicting global bee numbers, a few hives on the roof might be a good idea. Like Mr. Hemstock and Mr. Rehm, Mr. Garr visits the breezy, sky-bound roof meadow even when he doesn't need to. "It's like being in a field four storeys in the air."

Mr. Hemstock hopes green roofs and courtyards will soon stretch side by side across downtown Vancouver. "When you go up there and look around," he says, "you can see how, with a continuous chain of these, you could connect the North Shore mountains across the inlet, to Stanley Park and this green roof, to False Creek and Pacific Spirit Park at UBC." On the ground, but up in the air, just like the city hopes to be.