Some varieties include: Milii (Crown of Thorns), Coral Cactus (lactea grafted onto neriifolia)
Best possible light for all species of Euphorbia in winter. Succulent varieties can tolerate direct sun all year. Avoid direct summer sun for e. pulcherrima (poinsettia).
Water freely from spring to autumn allowing the soil to dry between waterings. Water sparingly in winter.
Euphorbia will thrive in average indoor temperatures, and outdoors can be grown year-round in U.S.D.A. growing zones 10 and 11, or during the warmer months in temperate zones.
Fertilize with a weak (diluted) houseplant fertilizer in summer.
Repot into a planter with holes for drainage, using a cactus soil mix or a 50/50 combination of regular potting mix and sand. Plant shallowly, just covering the roots. Then press down the soil to anchor the plant and prevent it from leaning or tipping.