This shrubby perennial grows to a height of 5 feet with full sun and moderate moisture conditions. It has mauve-blue flower spikes that measure 6 inches or longer, covered with hundreds of tiny florets that attract butterflies and hummingbirds from May through October. Like other butterfly bushes, it will regrow from the root system after a hard winter. It can be used as a specimen in a hedge or a border and is resistant to deer.