Common Name: spurge
Type: Herbaceous perennial
Family: Euphorbiaceae
Zone: 5 to 9
Height: 2.00 to 3.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: June to July
Bloom Description: Green with orange bracts
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Flower: Showy
Tolerate: Rabbit, Deer, Drought, 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. Plants are not reliably winter hardy throughout USDA Zone 5 where they should be sited in protected locations. This hybrid is sterile.
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.
'Autumn Sunset' is a euphorbia hybrid that typically grows on upright green stems to 36-42" tall. Parents of this plant are Euphorbia griffithii 'Fireglow' (female) and Euphorbia polychroma (male). 'Autumn Sunset' is noted for its bright orange floral bracts. Compound cymes of inconspicuous true flowers bloom at the stem ends in late spring to early summer (June - July). Although the greenish true flowers (borne in cyathia) lack sepals or petals and are not showy, these flowers are subtended by long-lasting, bright orange floral bracts which are exceptionally showy. Flower color comes from the floral bracts. Oblanceolate basal leaves (to 6" long) and smaller whorled stem leaves (to 2" long) are yellowish-green. Genus name honors Greek physician Euphorbus (52 B.C - 23 A.D.). U.S. Plant Patent PP20,496 was issued on November 17, 2009.
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.
Uses
Beds, borders and rock gardens.