The leader of the free world basked in the beauty of Laura Dowling's floral arrangements — and now you can, too. Laura Dowling, former chief floral designer of the White House, will appear Feb. 23 during The Columbus Dispatch Home & Garden Show presented by Ohio Mulch, which runs Feb. 22 through March 1 at the Ohio Expo Center, 717 E. 17th Ave. The show is closed Feb. 25.Dowling will share behind-the-scenes stories from her time as the White House's chief floral designer and