Great Blue Lobelia is a showy plant and produces welcome color diversity during late summer and fall, with its violet-blue spikes. It can grow in full sun but prefers part shade and wet to mesic soils. Reaching 1-4’, it’s a nice counterpoint to the mostly ... yellow flowers of late summer and early fall. It attracts primarily bumble bees and less often, hummingbirds. Also commonly called blue cardinal flower.