Sunnyside Garden is unique in that they don't JUST sell plants. They do have a complete greenhouse, and a knowledgable staff that can help you figure out when and where to plant certain flowers & shrubs.
They also sell some fun metal sculptures and interesting pots, wreaths, and other home decor. Plus some stone statues. The interesting thing is that some of the stuff they sell is actually made by local Tulsa artists... you're not going to find that at Lowes.