Dahlia Blue Bell is a decorative, tuberous perennial forming a bushy upright plant with dark stems and divided mid-green leaves. It reaches around ninety centimetres in height and carries strong flowering stems above a dense leafy base.
From midsummer until frost, rounded fully double flower heads open in rich violet-purple, darkest towards the centre and gradually softening to lavender-blue at the broad petal edges. Mature blooms can reach about fifteen centimetres across and are valuable in borders and as cut flowers.
Grow in fertile, humus-rich, moist but well-drained soil in full sun and a sheltered position. Water consistently, feed during active growth, stake before stems lean, and deadhead to extend flowering. In regions where tubers are not reliably hardy, lift them after seasonal dieback and store them dry before replanting after frost danger has passed.