When I went on the University Place Garden Tour one of the volunteers gave me a list of some of the local gardening centers. One of these centers was the Purple Geranium Greenhouse at 12615 47th Ave E, Tacoma, proximate to Canyon Road and 120th Street. Although it is close to my house (about 20 minutes away) it felt like a drive in the country. I was pleased to see that it was a well stocked professionally run gardening center on a lovely site. Their prices were righteous and my 
questions were answered right away. Of course it is less extensive than the big centers (Watson’s, Molbak’s, etc.) and there is almost none of the decorative items, but really that just makes it easier. I toured the place, took some photos, got some advice and purchased some plants in about 30 minutes. When I stopped for an iced coffee afterward the cashier asked me what I was up to today and I told her I went to the Purple Geranium. She gushed that it was the best place around to buy plants!
Do be aware that they have a limited season (April 1st to August 1st) and limited hours, so check out their Facebook Page before going.