Rudbeckia hirta An important native prairie plant used by Native Americans and early settlers medicinally and as an important component in dye making. Black Eyed Susanís sunny yellow flowers brighten the late summer garden and feed both butterflies and bees. The seed heads then should be left on the plants as an important food source for wild birds. 2-3 feet. Full sun. Seeds should be planted in cold conditions. Perennial. 100+ seeds.