Allow the soil to dry out completely between waterings. Euphorbia oblongata is drought-tolerant once established. Overwatering can lead to root rot, so err on the side of underwatering.

Water thoroughly when the top few centimeters of soil are dry.

Prune after flowering to maintain shape and prevent excessive self-seeding. Remove spent flower stalks. If the plant becomes leggy or untidy, you can cut it back significantly in late winter or early spring.

Wear gloves, as the sap can be irritating.

Easily propagated from seed sown in spring or autumn, or by cuttings taken in late spring. Seeds may require stratification.

Cuttings should be allowed to 'heal' for a day or two before planting to prevent the sap from interfering with rooting.

Young plants may need repotting annually in spring. Mature plants are often best left undisturbed. Repot only when root-bound.

Use a well-draining potting mix, such as a cactus or succulent blend, to ensure good aeration and drainage.