How to prune symphyotrichum oblongifolium 'raydon's favorite'

Chelsea chop in late May; cut back after flowering or in early spring. In late May, shear stems by about half with clean shears. After autumn flowering, cut all growth to within a few inches of the ground.

Chelsea chop once in late spring; full cut-back once annually. This aromatic aster benefits from a Chelsea chop — cutting stems back by half in late spring — to prevent flopping and produce a denser, more floriferous plant in autumn. Deadhead to prolong bloom. Cut the whole clump back hard to ground level in late autumn or early spring to renew growth.

In late May, shear stems by about half with clean shears. After autumn flowering, cut all growth to within a few inches of the ground.