Already vegetarian, organic and natural, Down to Earth stores will be celebrating Earth Day Wednesday with a switch to biodegradable shopping bags.

In addition, from 8 a.m. to 10 p.m., an Earth Day "Think Big! Save money and the planet through bulk purchases" sale means at least 30 percent savings on more than 50 products, including "green" household cleaners.

The biodegradable bags will break down completely into water, carbon dioxide and harmless humus in land and in the ocean, without leaving toxins behind. The process takes 9 months to 5 years, but compared to the centuries it takes for plastic to break down, it's a significant improvement, according to Down to Earth's CEO Mark Fergusson.