How to prune achillea ptarmica 'the pearl'

Deadhead throughout summer; cut back in autumn after flowering. Remove spent flower stems to the basal mat as they fade. After the main flush, cut the whole clump to 10 cm. Lift and divide in spring, replanting only vigorous outer portions to check the plant's spreading habit.

Deadhead regularly; cutback annually; divide every 2 years. Achillea ptarmica 'The Pearl' is vigorous and can spread freely, so prompt deadheading is important to limit self-seeding and encourage repeat bloom. Cut spent stems back to basal foliage. Shear the whole plant to the ground-level rosette in autumn. Divide every 2 years to control spread and maintain flowering quality.

Remove spent flower stems to the basal mat as they fade. After the main flush, cut the whole clump to 10 cm. Lift and divide in spring, replanting only vigorous outer portions to check the plant's spreading habit.