Plant symposium Adkin's Arboretum's third annual Tent Symposium will be held from noon to 3 p.m. at 12610 Eveland Road in Ridgely. David George, author of "The Forest Unseen: A Year's Watch in Nature," will speak. Visitors can also enjoy guided walks, the Native Plant Nursery and nature exhibits. Cost is $45, $35 for members, which includes lunch. For registration and information, call 410-634-2847, ext. 0 or go to adkinsarboretum.org.