Steeplebush prefers consistently moist soil. Water regularly, especially during dry periods, to maintain soil hydration. Avoid waterlogged conditions, as this can lead to root rot.

Deep watering is more beneficial than frequent shallow watering to encourage strong root development.

Prune Spiraea tomentosa in late winter or early spring before new growth begins. Remove any dead, damaged, or crossing branches.

To encourage bushier growth and more prolific blooms, you can cut back about one-third of the oldest stems to the ground annually.

Propagation is typically done through softwood cuttings taken in early summer or semi-hardwood cuttings in mid-summer. Root cuttings in a well-draining potting mix.

Division of established clumps in early spring is another effective method for increasing plant numbers.

Repotting is primarily for container-grown plants or when transplanting nursery stock. If the plant is root-bound in a container, repot in spring to a slightly larger pot with fresh, well-draining soil.

Ensure good drainage to prevent water accumulation around the roots.