Consider the hardy "Johnson's Blue" geranium, commonly known as cranesbill, for a border or rock garden. It is a clump-forming plant with 2-inch-wide periwinkle-blue flowers that bloom profusely from late spring through summer. The leaves turn orange in the fall, adding new color interest in the garden. This variety of hardy geranium does well in zones 5 to 8.
Choose a site with full sun (afternoon shade in southern areas). This plant may spread, so choose a site accordingly. Soil should be well-drained but can be on the dry side.
Plant container-grown cranesbill in spring after the date of the average last frost. Dig a hole twice the size of the root-ball. Place the plant in the hole and backfill, compacting the soil to remove any air pockets. Water generously. Space plants at least 2 feet apart.
After planting, put mulch around the base of the plant to keep in moisture.
After flowers are spent, trim back the plant to encourage a second flowering.
If they become overcrowded, "Johnson's Blue" can be divided. This can be done in the early spring or fall.