Water Eryngium agavifolium thoroughly when the top 2-3 cm of soil feels dry to the touch. This plant prefers well-drained soil and is drought-tolerant once established. Avoid overwatering, as it can lead to root rot.

Reduce watering frequency during winter dormancy to prevent waterlogged conditions.

Prune Eryngium agavifolium after flowering to remove spent flower stalks and maintain a tidy appearance. Cut back dead or damaged foliage in late winter or early spring before new growth emerges.

Deadheading can prevent self-seeding if unwanted, but the dried flower heads provide winter interest.

Propagate Eryngium agavifolium by division in spring. Carefully lift the plant and divide the root ball into sections, ensuring each division has roots and shoots.

Alternatively, sow seeds in autumn or early spring, although germination can be erratic. Cuttings are generally less successful.

Repotting Eryngium agavifolium is infrequent as it prefers to be slightly pot-bound. If the plant outgrows its container, typically every 2-3 years, repot in spring into a slightly larger pot with well-draining soil.

Ensure the new pot has adequate drainage holes to prevent waterlogging.