Euphorbia polygona cluster of grey-green deeply ribbed columns with small maroon flowers in a rock garden

Euphorbia Polygona

Euphorbia polygona
Categories:
Cacti & Succulents  ·  
Other Succulents
Light
Morning sun / afternoon shade
Water
Low water; water deeply, then let soil dry completely. Reduce watering substantially in winter; avoid keeping roots wet during extreme heat.
Size
3-5 ft tall × 2-4 ft wide
Habit
Clustering succulent
Toxicity
Toxic if Ingested; Sap Irritant
Description
A South African succulent with upright, deeply ribbed, spiny stems that form sculptural clusters. Resembles a cactus but belongs to the euphorbia family.
Bloom Time
Spring to early summer
Deciduous / Evergreen
Evergreen
Special Features
Architectural Form, Drought Tolerant
Growth Rate
Slow
Growth Habit
Clustering succulent
Mature Size
3-5 ft tall × 2-4 ft wide
Flower Color
Dark purple to maroon (cyathia)
Foliage Color
Gray-green
Landscape Use
Border / Bed, Cactus / Succulent Garden, Container / Patio, Desert / Xeriscape
Garden Style
Container / Patio, Desert / Xeriscape
Soil
Amended / Rich, Sandy / Rocky, Well-Drained
Companion Plants
Afternoon-shaded settings, Compact aloes, Gasteria, Golden barrel cactus, Zebra haworthia
Toxic if Ingested; Sap Irritant
Toxic if ingested; milky sap is a severe skin/eye irritant
Care Instructions

Light: Bright light with morning sun and afternoon shade in Phoenix; acclimate gradually to direct sun to prevent scorching.

Water: Low water; water deeply, then let soil dry completely. Reduce watering substantially in winter; avoid keeping roots wet during extreme heat.

Soil: Very well-drained, gritty cactus mix amended with pumice or gravel. Use containers with drainage holes or raised planting beds.

Mature size: Typically 2–4 feet tall and 1–3 feet wide as a clump; individual stems remain relatively narrow.

Bloom: Usually blooms in spring through summer on established plants; flowering varies with growing conditions.

Evergreen / deciduous: Evergreen succulent; green stems provide the lasting display, while tiny leaves are short-lived.

Growth rate: Slow to moderate in warm weather.