Crown of thorns plant (Euphorbia milii) is a succulent grown as a houseplant. This plant produces woody stems up to 7 feet tall covered with thorns. Crown of thorns plant require certain qualities in soil in order to grow and flower well.
The soil used for a crown of thorns plant must drain quickly. If the soil holds onto too much moisture, this succulent looses its leaves during the growing season. If left in wet soil, the plant dies.
A crown of thorns plant grows well in soil that is not very fertile. A commercial cactus soil works well for this plant. Create your own soil mixture by combining equal parts of potting soil, sand and pea-sized gravel.
Crown of thorns stem cuttings are propagated in a mixture of equal parts potting soil and sand. Keep the cuttings barely moist and shaded for two weeks. Roots soon form, and new growth starts.