How to Prune clustered bellflower 'Emerald'?
Cut back after flowering to promote extended flowering

clustered bellflower 'Emerald' · Campanula glomerata 'Emerald'
Will grow well in fertile, neutral to alkaline soil that is moist but well-drained, in full sun or partial shade avoiding wet conditions in winter. A semi-shade position will ensure the best flower colour is preserved.
Cut back after flowering to promote extended flowering