Salem has joined the list of cities in Oregon banning single use plastic bags in stores. Salem City Council approved the ban at its meeting last night. The city joins Portland, Corvallis and McMinnville, who already have similar bans. In Salem’s case, larger retailers such as Walmart and Costco have until next April to comply. Smaller businesses can take until next September. After that time plastic won’t be offered anymore at checkout. But customers can pay extra for a p aper bag or bring their own.