Water consistently, especially during dry periods. Ammi majus prefers evenly moist soil but can tolerate brief dry spells once established. Avoid overwatering, which can lead to root rot.

Water at the base of the plant to keep foliage dry and prevent fungal diseases.

Deadheading spent flowers will encourage more blooms and prevent the plant from self-seeding excessively. If the plant becomes leggy, light pruning can help maintain a more compact shape.

Remove any yellowing or dead foliage promptly to maintain plant health and appearance.

Ammi majus is easily grown from seed, typically sown directly outdoors in early spring or fall. Seeds germinate best with light exposure, so sow them thinly on the soil surface and press down gently.

Thin seedlings to the desired spacing once they are large enough to handle.

Ammi majus is an annual and typically does not require repotting. If grown in containers and it becomes root-bound, it can be transplanted to a larger pot in spring.

Use a well-draining potting mix and water thoroughly after transplanting.