Swamp milkweed thrives in consistently moist soil, mimicking its native wetland habitat. Water deeply when the top few centimeters of soil feel dry.

Avoid letting the plant sit in stagnant water, which can lead to root rot, but ensure the soil never completely dries out, especially during hot weather.

Pruning is mainly done to maintain shape and encourage bushier growth, or to remove dead or damaged stems. Cut back plants in late fall or early spring to about 10-15 cm above the ground.

Deadheading spent flowers can prevent excessive self-seeding if this is a concern, though it's rarely necessary.

Swamp milkweed can be propagated from seeds sown in fall or stratified indoors, or by stem cuttings taken in early summer. Seeds require a period of cold, moist stratification to germinate effectively.

Cuttings should be rooted in moist potting mix and can be transplanted once established.

Repotting is typically only necessary for container-grown plants or when dividing established clumps. Swamp milkweed prefers to be slightly root-bound and can be transplanted directly into the garden after purchase.

If repotting, choose a container that is only slightly larger than the current one, and ensure it has good drainage.