500 GREAT BLUE LOBELIA Lobelia Siphilitica Flower Seeds BLOOM TIME: All Summer HARDINESS ZONE: 3 - 9 PLANT HEIGHT: 12 - 36" . . . PLANT SPACING: 15 - 18" LIGHT REQUIREMENTS: Sun - Part Shade . . . SOIL / WATER: Average - Moist This is the blue version of the Red Cardinal Lobelia. The two look great paired together for a colorful show! It also attracts butterflies and HUMMINGBIRDS.