Scott Arboretum curator Andrew Bunting takes guests on a tour previously available only to arboretum interns. The guided walk looks at recent acquisitions and why certain plants are removed. Free. 500 College Ave., Swarthmore. 2:30 to 3:30 p.m. www.scottarboretum.org; 610-328-8025.
Philadelphia Phillies historian Rich Wescott signs books at Media-Upper Providence Free Library. Wescott serves on the Philadelphia Hall of Fame committee, and has written 18 books, including three editions of the Phillies Encyclopedia and Tales from the Phillies Dugout. Free. 1 E. Front St., Media. 7 to 8:30 p.m. 610-566-1918.
Kids mean business
Enterprising young Swarthmore residents take to the streets during the Kids' Sidewalk Sale. Free admission. Borough Hall parking lot, Park and Dartmouth Avenues, Swarthmore. Noon to 4 p.m. www.swarthmorepa.org; 610-543-4599.
Watercolorist Kathy Johnston displays works at the Darlington Arts Center. Free. 977 Shavertown Rd., Boothwyn. 10 a.m. to 8 p.m. Monday through Friday, and 10 a.m. to 4 p.m. Saturday. Show runs through May 30. www.darlingtonarts.org; 610-358-3632.