Amaranthus spinosus prefers consistently moist soil, especially during active growth. Water deeply when the top 2-3 cm of soil feels dry. Avoid waterlogging, which can lead to root rot.

Reduce watering frequency during cooler months or when the plant is dormant, allowing the soil to dry out slightly more between waterings.

Pruning is primarily for shaping and managing size. Pinch back young plants to encourage bushier growth. Remove spent flower stalks to prevent self-seeding if desired, or to encourage a second bloom.

Amaranthus spinosus can become quite large, so pruning may be necessary to maintain desired dimensions.

Amaranthus spinosus is easily propagated by seeds. Sow seeds directly outdoors after the last frost, or start them indoors 4-6 weeks prior. Seeds germinate quickly in warm, moist soil.

Transplants can be placed in their final location when they have a few true leaves and are hardened off.

Repotting is generally not necessary for Amaranthus spinosus, as it is often grown as an annual.

If grown in a container and it becomes root-bound, repot in the spring to a slightly larger container with fresh, well-draining potting mix. Ensure the new pot has adequate drainage holes.