Perennials flowers bloom back year after year when planted in their hardiness zones. Planted outside of their zones, they will usually only last for one year and new plants will have to be stated from seed the year after. Perennials with blue flowers come in all shapes and sizes-- from tall enough to be cut flowers to short enough to be a ground cover--and in hues from pale blue to almost purple.
Blue bugloss (Anchusa azurea), hardy in zones 3 through 8, grows well throughout most of the contiguous United States. The plant grows in mounds 3 to 5 feet in height and 2 feet wide. Blue bugloss does best in areas protected from high winds. The plant needs full sun--at least six hours of sunshine a day--and a rich, moist soil. Plant blue bugloss where it will get sunshine either in the early morning or late afternoon and where it will get shade during midday. Cut the flower stalks back to the ground when the flowers are done so the plant can store up energy over the winter for next year's growth. The flowers make good additions to cut flower arrangements.
Perennial geraniums, also known as the cranesbill, can be used in perennial borders, shrub borders, rock gardens and woodlands. They flower in late spring producing a single flower that is under 2 inches in width and round leaves that will spread out as far as the plant grows in height---anywhere from a few inches to 3 feet. Hardy in zones 4 though 8, perennial geraniums can grow in full sun or partial shade and any type of well-drained soil.
Chionodoxa (Chionodoxa forbesii) is also known as glory of the snow because it blooms so early in the season that its flowers poke up through the snow. The plant is hardy in zones 3 through 8 and produces a blue flower with a white middle. The star-shaped flowers measure ½ to ¾ inches widend grow in clumps of 5 to 10 blooms that reach a height of about 6 inches. Plant Chionodoxa bulbs in the fall in well-drained soil that gets full to partial sun. Chionodoxa thrives under trees, in rock gardens, in flower beds or in a woodland setting.