Perennial ragweed is drought-tolerant once established. Water deeply but infrequently, allowing the soil to dry out between waterings. Overwatering can lead to root rot, especially in poorly draining soils.

Aim for consistent moisture during its initial growth phase in spring.

Pruning is primarily for controlling spread and maintaining a tidy appearance. Cut back dead or damaged stems in late winter or early spring.

If it becomes too aggressive, mowing or cutting it back in late summer can prevent seed production and reduce its vigor for the following season.

Perennial ragweed readily self-seeds and spreads via rhizomes. To propagate intentionally, sow seeds in early spring directly outdoors or start them indoors a few weeks prior.

Division of established clumps in early spring is also an effective method for propagation.

Repotting is not typically necessary for perennial ragweed as it is a hardy, herbaceous perennial that spreads naturally. If growing in a container, it may eventually outgrow its pot, at which point division and repotting into a larger container or directly into the ground is recommended in spring.