This is Verbena hastata, also known as Blue Vervain. These perennial butterfly plants like to live in the full sun or partial shade would do as well. Some can get as tall as 6 feet, and when in full bloom they put on quite a show. While attracting several birds, bees and butterflies, this plant is larval host plant for the Common Buckeye butterfly. It is also a nectar plant for the Gulf Fritillary, Sleepy Orange, Least Skipper, Pecks Skipper, Cobweb Skipper, Dusted Skipper, Broad-winged Skipper, and Clouded Skipper butterflies. It is also a nectar source for the Snowberry Clearwing Moth. USDA Hardiness Zones 3 to 8