(Newser) – And you thought other big-box superstores were making an attempt to go green. A chain nicknamed the "Walmart of Weed" opened its third and largest outlet today in Phoenix, Arizona, where voters approved medical marijuana last fall. Although you can't buy pot in the first weGrow Store outside California, it's a one-stop shop for hydroponic equipment such as fertilizer and lights needed to grow marijuana, reports CNN.

The company founder sees a billion-dollar opportunity in Arizona from a projected 100,000 residents who will be approved for cannabis cards. "Medical marijuana cultivating, dispensing, and consuming will exist with or without governmental approval," he says. "It's time to tax and regulate this industry so legitimate business people and patients are not criminalized." The opening comes after Jan Brewer and the state sued the Justice Department for clarification on federal law, a move that could delay the approval of dispensaries in the state. (Read more medical marijuana stories.)

