When you survey the piles of dead trees lining the road a week after Christmas, it’s hard not to conclude that you should give Mother Nature a break and buy a reusable artificial tree. But before you go plastic, you should consider some surprising facts.

Despite what many people think, you’re not depleting the forest when you buy a real tree, says Allyson Brady, executive director of the Saskatchewan Environmental Society. Almost all Christmas trees are grown on farms, like corn or pumpkins. For every tree that’s harvested, up to three more are planted. Since the tree farmer doesn’t want to go out of business, there is no danger that trees won’t be replaced.

It takes between seven and 10 years for a Christmas tree to reach living-room size. During that time, the tree absorbs carbon dioxide, releases oxygen, and provides a habitat for wildlife. Shipping the tree does consume fuel, but in Canada, a lot of trees are grown locally, which minimizes the impact.

When we’re done with our Christmas trees, most municipalities collect them and turn them into wood chips for parks and mulch for gardens. Real trees are natural, renewable resources that are easily absorbed back into the ecosystem.

Artificial trees are not. Most are manufactured in China and are made with polyvinyl chloride (PVC), a polymer derived from oil. Brady says PVC is “one of the worst plastics for the environment.” To make matters worse, the manufacturing process produces carbon dioxide; so does shipping the tree here from overseas.

It’s true that if artificial trees are used for many years, their environmental impact is diluted—but they all get thrown out sooner or later, and they’re not biodegradable. “Trees that are made of PVC probably won’t break down for 200 years,” says Brady. “And once the PVC does break down and starts leaching into the soil, it creates some very toxic chemicals.”

So which tree should you choose if you want a green Christmas? “If you were really determined not to have an environmental impact, I suppose you wouldn’t have a tree at all,” says Brady. “You could just decorate a potted plant.”

But even Brady doesn’t go that far. She may be an environmentalist by day, but come Christmas Eve, she says you can’t beat the look and smell of a real tree in your living room. “I get them mainly because they’re nostalgic for me,” she says. “But I was glad when I did the research and found that it’s not that big a deal.”