Euphorbia royleana
Light: Full sun to light shade; afternoon shade is beneficial in Phoenix, especially for young or container-grown plants. Acclimate gradually to intense sun.
Water: Low water once established; water deeply, then let soil dry thoroughly. Water sparingly during cool weather and avoid watering cold, dormant plants.
Soil: Very well-drained, sandy or gravelly soil. Use a raised planting area in heavy soil and a gritty cactus mix in containers.
Mature size: Typically 10–20 feet tall and 6–12 feet wide outdoors; usually smaller in containers.
Bloom: Small, inconspicuous blooms typically appear in spring to early summer on mature plants; flowering varies with growing conditions.
Evergreen / deciduous: Seasonally deciduous leaves; green succulent stems remain year-round. Leaves often drop during drought or cool weather.
Growth rate: Moderate in warm weather with appropriate watering; slower in containers or under very dry conditions.