The cardinal plant, also known as Lobelia cardinalis, is a water-loving plant that produces spike-like, bright-red flowers from the late spring into the early summer. They have purplish foliage that attracts hummingbirds and swallowtail butterflies.
Cardinal plants are native to regions of the United States and Canada and grow between 2 to 4 feet tall and between 1 ½ to 2 feet wide when mature. They adapt well to most garden conditions, especially in areas that are moist, such as beside water features and ponds. Cardinal plants grow best in the nontropical regions, where the minimum winter temperatures remain above minus 30 degrees Fahrenheit.