One of the earlier blue cultivars hardy to zone #5. Probably wouldn't waste my time growing this in zone #5, since it has been superseded by many other Hydrangea.
Soil & Site
ph of the soil will determine the color of the flower
In zone #5 this plant has winter killed to ground level almost every year. This effects the flower production and ultimate size of the plant.
blue in acid soils and pink in basic
4-8" long, simple, opposite and have a fleshy, waxy feel
Can reach up to 6 feet but seems to winter kill back to the ground and the height is more around 3-4 feet.
My experience is this not a good dependable plant for hardiness zone #5 in southeastern Wisconsin. Very little flower production because of winter kill. But I have people tell me they have some luck with Nikko Blue.