Hydrangea Serrata Crüg Cobalt. A choice specimen with bright blue flowers. Crüg cobalt originally comes from crüg farm in the uk it was seedling originating from seed collections gathered from the Mt. Unzen area of Kyushu, Japan in 1998. Of a very floriferous small form of this amenable deciduous lace cap species hydrangea, bearing corymbs of strong blue lace-cap (pink in alkaline soil). Flowers Nov-May. The sterile florets deepening in colour with age, availing us with a cool blue effect. While the foliage ages to a purple cast if exposed to sun. Neat bush to about 80cm high and same spread.