Perovskia has a handsome branching habit and looks airy with small grey leaves in spring, blue flowers in summer, and white skeletal branches in fall & winter.
Campanulas, or bellflowers, are plants with bell-shaped blue or white blooms, and they range in height from ground-hugging dwarfs to plants that grow to 6 feet.
Chives are rampant self seeders, and if they are not dead headed they will produce far too many new plants.
Corydalis has delicate lacy-looking foliage and racemes of spurred flowers in the spring.
There are about 300 different Campanulas, commonly known as “bellflowers.”