Jules Verne's nursery :: The Star

Inco grows 50,000 subterranean seedlings a season of red pine and jack pine more than a kilometre down the 2.3-kilometre mine shaft... After three months of germination, the 5-inch pellets and seedlings are then brought up to the surface and planted on and around Inco property to fulfill its obligation to re-claim the barren land after years of wear and tear from mining, smelting and refining. Another 200,000 seedlings are also grown annually in the greenhouse operated year-round at Copper Cliff.

...It turns out that a steamy mine is a perfect environment for tree growing. For starters there's a constant humidity and geothermal heat of 25C year-round. "The underground nursery works because there is an ambient rock temperature, it's warm and you don't have to heat a greenhouse in cold weather in Sudbury. And it makes good sense because the facility is available so there's no added cost at Creighton," explains Taylor.

Fertilizer, electricity and water are pumped in at minimal cost compared to the expense of heating a regular greenhouse through the sub-zero winters, he says. The underground forest of baby trees is Y-shaped and fairly narrow at 10 feet wide and 600 feet long with fertilizer and water storage tanks at the wide end. It needs 2,000 litres of both water and fertilizer per day, so the tanks are on timers. To get things going it requires 30 1,000-watt light bulbs to give it the artificial effect of sunlight, which stay on 24 hours a day the first week, then 18 on and 6 off for three weeks and then 12 on and off — just like outdoors — the rest of the time.