Crithmum maritimum thrives in well-drained conditions and is highly drought-tolerant once established. Water thoroughly but infrequently, allowing the soil to dry out completely between applications. Overwatering, especially in heavy soils, can lead to root rot. Reduce watering significantly during cooler months or periods of dormancy. Ensure excellent drainage in pots to prevent waterlogging, which is detrimental to this coastal succulent.

Pruning Crithmum maritimum is primarily for shaping, encouraging bushier growth, and harvesting its edible leaves. Lightly trim back leggy or overgrown stems in spring to maintain a compact form. Remove any dead, damaged, or yellowing foliage as needed throughout the year to keep the plant healthy and tidy. Regular harvesting of the outer stems also acts as a form of pruning, promoting continuous fresh growth.

Rock Samphire can be propagated by seed, division, or cuttings. Seeds can be sown in spring in well-drained, sandy compost. Cuttings of non-flowering shoots can be taken in late spring or early summer and rooted in moist sand. Established clumps can be carefully divided in spring.

Repotting is generally only necessary for container-grown plants when they become root-bound or the growing medium is depleted. Choose a pot only slightly larger than the previous one, ensuring good drainage. Repot in spring using a gritty, well-draining potting mix suitable for succulents or herbs.