Every time I bump into this Phacelia clump I notice the number of insects on the flowers. I think this photo is probably of Bombus terrestris the Buff-tailed bumble bee. They live underground just like the bumble bee in the Tale of ‘Mrs Tittlemouse’ who lived in a bank under a hedgerow. Stroud is a ‘Bee Town’, populated with ‘bee guardians’ – such wholesome people live here.
Phacelia is an essential flower for my summer plot, and these were overwintered plants as it is a hardy annual. The plant is Phacelia tanacetifolia which you will find offered for sale as a green manure seed, not an ornamental flower. The pretty leaves resemble tansy as the name suggests, and soft blue flowers last for ages, attracting masses of insects. I grow it mostly as a companion plant but also use it as a green manure for digging in or composting. It is very easy to grow, self seeds freely and smothers weeds, while the extensive roots improve soil structure.