Allow the soil to dry out completely between waterings. Euphorbia helioscopia is drought-tolerant and prefers dry conditions. Overwatering can lead to root rot, so err on the side of underwatering.

Water thoroughly when the plant shows signs of wilting.

Pruning is generally not required for Euphorbia helioscopia. If plants become leggy or overgrown, they can be cut back in late spring after flowering. This can encourage bushier growth.

Remember to wear gloves as the sap is irritating.

Euphorbia helioscopia self-seeds readily. To propagate intentionally, collect seeds after they mature in summer and sow them in autumn or early spring in well-draining soil.

Alternatively, you can carefully divide established clumps in spring.

Repotting is rarely necessary for this species as it is often grown as an annual or short-lived perennial. If desired, repot in early spring before new growth begins.

Use a well-draining potting mix, and handle with care due to the irritating sap.