Common Name: spurge
Type: Herbaceous perennial
Family: Euphorbiaceae
Zone: 6 to 8
Height: 2.00 to 3.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: June to July
Bloom Description: Yellow
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Flower: Showy
Leaf: Colorful
Tolerate: Rabbit, Deer, Drought, Dry Soil, Air Pollution
Culture
Best grown in dry to medium, well-drained soils in full sun. Appreciates some afternoon shade in hot summer climates. However, clumps tend to open up and lose their attractive shape in too much shade. Must have sharply-drained soils. Wet soils, particularly in winter, can be fatal. Plants are tolerant of some poor soils, including rocky-sandy ones. Plants generally prefer a Mediterranean-type climate and may show some stress in hot and humid summers.
EXCALIBUR may not be reliably winter hardy in the St. Louis area where plants are best sited in a protected location.
Noteworthy Characteristics
Euphorbia is a genus of about 2,000 species of annuals, herbaceous perennials, trees, shrubs and succulents found in temperate, subtropical and tropical areas. All plant parts are toxic and can cause severe discomfort if eaten. The milky sap can cause skin irritation.
Genus name probably honors Euphorbus, physician to the King of Mauretania.
EXCALIBUR is a clump-forming perennial that is noted for its attractive foliage and long lasting flowers (actually yellow bracts). It typically grows to 3’ tall. Red-tinted early spring foliage. Mature green leaves have a light yellow central midrib. Yellow flowers in corymbs appear in summer with long-lasting pale yellow bracts. Pink stems turn deeper red in autumn.
Problems
No serious insect or disease problems. Use gloves when working with this plant. Some gardeners experience skin rashes from contact with the toxic plant sap of euphorbias. Deer tend to avoid this plant.
Uses
Beds, borders and rock gardens.