The 9th annual Green Thumb Gala, a major fundraiser for the Knoxville Botanical Garden and Arboretum, features silent and live auctions, garden tours, seated gourmet dinner, music and fine wines and spirits. Cocktails and silent auction begin at 5 p.m., followed by 6:30 p.m. dinner and 7:30 p.m. live auction. The 2018 theme is “If These Walls Could Talk,” a reference to the stone walls and historic structures built more than 100 years ago. Attire: garden party.