Water consistently, keeping the soil moist but not waterlogged. Allow the top inch of soil to dry out between waterings, especially during the growing season. Reduce watering in cooler months to prevent root rot.

Ensure good drainage to avoid fungal diseases.

Deadheading spent flowers encourages more blooms and prevents self-seeding if not desired. Light pruning can be done after flowering to maintain shape and tidiness.

Remove any yellowing or damaged foliage promptly to improve plant health and appearance.

Agrostemma brachylobum is typically grown from seed sown directly outdoors in early spring or autumn. Seeds require light to germinate, so sow them on the surface of the soil.

Germination can be slow and erratic, taking several weeks.

As Agrostemma brachylobum is often treated as an annual or short-lived perennial, frequent repotting is usually not necessary. If growing in pots and the plant becomes root-bound, repot into a slightly larger container in spring using well-draining potting mix.