How to prune cup plant

Early spring before new growth; deadhead in late summer to reduce self-seeding. Cut all stems to ground level in early spring. During the growing season, snip individual spent flower heads before seeds ripen if spread control is needed — avoid cutting multiple main stems at once to reduce disease risk.

Annually (spring cleanup); deadheading as needed through summer. Cup Plant (Silphium perfoliatum) benefits from minimal pruning. Cut plants to the ground in early spring before new growth emerges to tidy up and control spread. Deadhead spent flowers in late summer if you want to reduce aggressive self-seeding, or leave seed heads standing for winter bird feeding.

Cut all stems to ground level in early spring. During the growing season, snip individual spent flower heads before seeds ripen if spread control is needed — avoid cutting multiple main stems at once to reduce disease risk.