|The cultivar, 'A.T. Johnson' is a robust shrub, flowering in early summer and again in early fall with periwinkle blue flowers.Compact, low-growing, broad, evergreen shrub. Leaves are oblong, glossy, light green and finely toothed up to 2 inches long. Dark blue flowers are borne profusely in large lateral cymes up to 3 inches long. Excellent for a shrub border or against a sunny wall.