Campanula ‘Haylodgensis’ is a pretty bellflower with double blue flowers. I’m not sure if it is fully hardy in zone 3, but I’ll know by next spring. The zone recommendations for this perennial seem variable. [Update: the Campanula 'Haylodgensis' survived the zone 3 winter and are covered in buds the next season.]
Campanula ‘Haylodgensis’ is a cross between C. cochlearifolia (fairy thimble bellflower) and C. carpatica (Carpathian bellflower). It resembles C. cochlearifolia ‘Elizabeth Oliver’, being a low growing bellflower about 10 cm (4 in.) tall. The flowers are a similar light sky blue colour. However, they are slightly larger, more open, and have more petals than ‘Elizabeth Oliver’. Here’s a photo of an Elizabeth Oliver plant for comparison. You can read more about ‘Elizabeth Oliver’ in this previous post.
I’ve only had the Haylodge bellflower in my garden for a month now, but it has already becoming one of my favourite bellflowers. The flowers have a true blue colour, and being a double, they are very showy. I’m not sure of the blooming length yet, but I hope it has a long flowering time, similar to its 2 parents.
Campanula ‘Haylodgensis’ is a charming, elfin flower with a beautiful colour. I hope this perennial makes it through the winter, so I might throw an extra armload of leaves over it in the fall. Since it is a cross between 2 Campanula which do survive our cold winters, I’m optimistic about its chances.
There is more information and pictures of another double flowering bellflower in this post.
Here is an updated post about how Campanula ‘Haylodgensis’ survived the zone 3 winter and how well it has been doing.