If buying a used mattress is out of the question, then buying a "green" mattress is probably the next best option. But even that can be tricky. You want to steer clear of all the greenwashing (and there's a lot of it in mattress world).

The Green Guide's Mattress Buying Guide is a great place to start, if you're on the hunt for a new green mattress.

First, they take you through the basics: what to look for (organic cotton, natural latex) and what to look out for (the bad flame retardants).

They also provide a great product comparison grid and smart shopper's list.

It's a useful resource on a tricky topic.

image via Soapstar D'lux; Flickr.com