How to Prune sneezeweed 'Siesta'?
No pruning required, but deadheading will prolong flowering

sneezeweed 'Siesta' · Helenium autumnale 'Siesta'
Grow in full sun in fertile, moisture-retentive, humus-rich, well-drained soil; divide every two to three years to maintain vigour
No pruning required, but deadheading will prolong flowering