Cardinal Flower is named for its beautiful scarlet red flowers which are an important nectar source for hummingbirds and swallowtail butterflies. Lobelias produce a secondary compound known as "lobeline," which deters herbivores. The flowering spikes open from the bottom to the top and bloom for several weeks. They grow best in moist, rich soils in full sun to partial shade. Cardinal flower is a showy plant great for the garden or wetland planting