Water moderately during the growing season, allowing the soil to dry out slightly between waterings.

Reduce watering significantly in fall and winter, providing just enough to prevent the soil from becoming completely parched. Ensure good drainage to avoid waterlogging, which can lead to root rot.

Prune back dead or damaged stems at any time. After flowering, spent flower stalks can be removed to improve appearance and prevent self-seeding if desired.

In late fall or early spring, cut back the entire plant to a few inches above the ground to encourage vigorous new growth for the next season.

Propagate by division in early spring or fall. Carefully divide established clumps, ensuring each section has roots and shoots. Seeds can also be sown in fall or early spring, either directly outdoors or in a cold frame.

Stratification may improve germination rates for seeds.

Repotting is generally not required frequently for Silphium asperrimum, as it prefers to be undisturbed once established.

If repotting is necessary, for very young plants or for propagation purposes, do so in early spring before new growth begins. Use a well-draining potting mix and a pot that allows for adequate root space.