Buddleja 'West Hill' is an old hybrid cultivar, a full sister of 'Lochinch' and 'Mayford Purple' raised from a chance seedling found in the garden of the Earl of Stair at Lochinch Castle, Scotland, circa 1940, the shrub's parents believed to be Buddleja davidii and Buddleja fallowiana. 'West Hill' was introduced to commerce by the Sunningdale Nursery in 1959, and accorded the Royal Horticultural Society Award of Garden Merit (record 9300) in 2012, following the RHS Buddleja Euro-trials held at Wisley from 2008 to 2010.