B. ‘Buzz™ Indigo’ is a compact, bushy upright deciduous shrub with arching branches bearing lance-shaped pointed woolly grey-green leaves and dense panicles of fragrant deep blue flowers from early summer into autumn. (Thompson & Morgan quote)
This was only planted in the display beds at Longstock last autumn (2015) so is still a very small plant.
This series of plants was developed by Thompson & Morgan of Ipswich, Suffolk, England in a quest to create new hybrids which were more compact and easier to grow in the modern small garden. After 8 years of breeding and selection, the Buzz™ series was born.