Caryopteris clandonensis 'Dark night'
BLUE BEARD, Blue Sprirea, Blue Mist Shrub

Type: aromatic shrub; (trouble free) Herbaceaus Perennial
Bloom season: late summer through early  fall; after done blooming it turns a very pretty blue green color.
Height & Spread: 30" tall; 30" wide
Site & Soil: full sun; part shade; average, well drained soil
Attracts: bees love this bush, also attracts butterflies;
Trim: Cut back late winter, early spring, cut the previous year's growth back to young healthy buds and cut weak stems back to ground level. 
Zones: 5 - 9