Little Boy Blue is a deciduous shrub with a leggy, suckering growth habit and a somewhat irregular shape. Its medium green foliage is ovate to heart-shaped, reaching up to 5 inches in length.
This variety stands out with its round, compact form, growing up to 5 feet tall and wide, and producing delicate light blue flowers. As a cultivar of the common lilac—often called French lilac—it showcases highly fragrant blooms on dense panicles ranging from 4 to 8 inches long, appearing in late spring to early summer.