Plant or position crested Euphorbia plants in areas that are exposed to six or more hours of direct sunlight daily. Note that Euphorbia requires full sun for healthy growth and development.
Water crested Euphorbia thoroughly approximately every two weeks. Provide ground-grown Euphorbia with 1 inch of supplemental irrigation each time you water. Irrigate container-grown Euphorbia until the excess water drains from the bottom of the planting container. Allow the top 1 to 2 inches of soil to dry before the next irrigation.
Fertilize crested Euphorbia plants monthly during the spring and summer months, while the succulent is actively growing. Feed your Euphorbia with a water-soluble, all-purpose fertilizer or use a fertilizer product that has been specially formulated for succulent plants for more targeted fertilization. Follow the application instructions found on the fertilizer product.
Withhold water and fertilizer from your crested Euphorbia during the fall and winter months to allow it to enter dormancy; allowing the Euphorbia a rest period is essential to its long-term health. Water the Euphorbia thoroughly, using the process described in Step 2, just once in the middle of winter.