Everyone talks about blue hydrangeas, but very few people speak of blue mist shrub (Caryopteris x clandonensis).  I am not sure why.  Granted, hydrangea are generally bigger shrubs than caryopteris, which tops out at about three feet.  Standard hydrangea varieties, like the popular 'Nikko Blue',  have big round flowerheads that you can see from half a mile away, while blue mist shrub has more delicate flowers.

Still many of us have room in the garden for both and the addition of caryopteris takes up the blue color theme just as the hydrangea petals are drying to a pale blue-green. 

Caryopteris have medium green leaves that are often toothed.  The flower clusters, which draw butterflies, appear on the ends of the branches and give the plant an airy quality.   The stems have a pleasing aroma when they are cut. 

There is a pink-flowered caryopteris, but to my mind, the blue-flowered varieties are more desirable.  'Blue Mist' and 'Sunshine Blue' have bright blue flower clusters, and the latter is also brightened by vivid yellow-green leaves.  'Petit Bleu' is a compact variety, which is also very suitable for containers.

So take a chance on blue mist shrub.  For a small space investment you can reap big, colorful rewards.