Southwestern Spiny Rush thrives in consistently moist soil. Water regularly, especially during dry periods, ensuring the substrate does not completely dry out.

Aim for the soil to be damp to wet, mimicking its natural wetland or riparian habitat. Reduce watering slightly in cooler months but maintain consistent moisture.

Prune to remove dead or damaged foliage and to maintain shape. Cut back old stems near the base in late winter or early spring before new growth emerges.

This encourages vigorous new growth and prevents the plant from becoming overly dense or untidy.

Southwestern Spiny Rush is best propagated by division. In early spring, carefully divide established clumps into smaller sections, each with roots and shoots.

Replant divisions immediately into moist soil, watering well to help them establish.

Repotting is generally not required unless the plant is grown in a container and has become severely root-bound.

If necessary, repot in early spring into a slightly larger container with good drainage, using a heavy, moist soil mix. Ensure the crown is at soil level.