Rapistrum rugosum prefers consistently moist soil, especially during its active growth phase. Water thoroughly when the top 2-3 cm of soil feels dry to the touch. Avoid waterlogging, as this can lead to root rot.

Reduce watering during cooler periods or when the plant is dormant.

Pruning is generally not required for Rapistrum rugosum unless you need to remove dead, damaged, or crossing stems. If the plant becomes leggy, you can pinch back the tips in spring to encourage bushier growth.

Remove spent flower stalks to prevent self-seeding if unwanted.

Rapistrum rugosum is easily propagated by seeds. Sow seeds directly in the garden or in pots in early spring or autumn. Seeds germinate readily under good conditions.

You can also attempt propagation from stem cuttings taken in spring, though this is less common.

As an annual, Rapistrum rugosum is typically grown from seed each year and does not require repotting. If grown in a container and you wish to overwinter it (not typical for an annual), repot in early spring into a slightly larger pot with fresh potting mix.