6" Euphorbia Milii (Thorne of Jesus or Crown of Thornes)
As with most flowering plants, the better the sun exposure, the more blooms you will get. However, crown of thorns will reliably bloom as long as it gets at least three to four hours of bright, direct sunlight per day. Outdoors, try to place it under full sun. Indoors, place your plant in a west or south-facing spot during winter.
If growing outdoors, plant in well-draining soil and full sun. In dry climates, the plants will appreciate some mid-day shade. Crown of thorns is a very adaptable houseplant. It needs a well-draining potting mix and should not be planted in a container that is more than about an inch or two larger than the root ball. If there is excess soil, it will retain water and could cause the roots to rot.
Since it is a succulent, crown of thorns is very forgiving about water. Water when the soil feels dry about 1 inch below the surface. Water thoroughly and allow any excess to drain off. Do not let your plant sit in water or wet soil for prolonged periods of time or the roots will rot. Crown of thorns will go semi-dormant in the winter and need less frequent watering and not food.