Water regularly during the growing season, especially in dry periods. Allow the soil to dry slightly between waterings. Reduce watering in fall and winter. Provide good drainage to prevent root rot.

Established plants are relatively drought-tolerant but benefit from occasional deep watering during prolonged dry spells.

Prune California sweetshrub after flowering to maintain shape and size, or to remove dead, damaged, or crossing branches. Minimal pruning is usually required. Heavy pruning can reduce flowering for the following season.

Remove any suckers that emerge from the base of the plant to maintain a desired form.

Propagate Calycanthus occidentalis from seed, which requires stratification (a period of cold treatment), or from semi-hardwood cuttings taken in summer.

Cuttings should be treated with rooting hormone and placed in a moist, well-draining medium. Germination from seed can be slow and inconsistent.

Repot young plants every 2-3 years into a slightly larger container to accommodate root growth. Mature plants are best left undisturbed in the ground. When repotting, use a well-draining potting mix.

Ensure the new pot has adequate drainage holes to prevent waterlogging.