| 'Grey Dawn'|| UK|
Buddleja davidii 'Grey Dawn' is a British cultivar raised by the Lavender Garden, Gloucestershire, UK, and introduced to commerce in 2009. 
Buddleja davidii 'Grey Dawn' Wikipedia
'Grey Dawn' is a large, spreading shrub, distinguished by its compound panicles similar to 'Dartmoor', but for the blue flowers which can have a greyish hue.
'Grey Dawn' is rare in cultivation, and is not known to have been introduced to North America or continental Europe. Hardiness: USDA zones 5 - 9.