Euphorbia dulcis aka Sweet Spurge

Euphorbia dulcis, or sweet spurge, is a perennial in the spurge family, Euphorbiaceae. It is native across much of Europe. The RHS does not list it as native to Britain or Ireland. This plant forms a low, bushy mound and spreads by rhizomes. Its compact shape suits beds, borders, and small groups.

Plants grow about 0.75–1.7 feet (0.23–0.51 m) tall and wide. Upright stems carry dark green to bronze-green leaves. These reach about 0.25 feet (0.08 m) long. Their shape ranges from oblong to lance-shaped, with the broader end toward the tip. The foliage also adds interest in fall. Gardeners can use this low mound as ground cover. It also suits cottage gardens, mixed borders, and containers.

Flowers appear from May to June. Their yellow tones may carry a purple tint. Greenish-yellow bracts surround the small flower structures and provide much of the display. The flowers lack both petals and sepals. Each cyathium groups a single female flower with several male flowers. These consist of a pistil and single stamens, respectively. The cupped bracts frame these small parts. Plants can self-seed in the garden.

Sweet spurge grows in full sun or partial shade. It prefers humus-rich soil with sharp drainage. It also tolerates some poor soil, including rocky or sandy ground. Established plants withstand drought, but benefit from moderate, even moisture. Too much water can kill them. Cool summers suit this plant best. Give it some afternoon shade where summers turn hot. It tends to struggle with the hot, humid summers of the southeastern United States. It is winter hardy in USDA zones 5–8.

This is a low-maintenance plant when its site meets those needs. It tolerates dry soil, shallow rocky ground, and urban conditions. Deer and rabbits tend to leave it alone. No serious pest or disease problems are known from the supplied account. Still, aphids, spider mites, mealybugs, and nematodes can cause trouble. Fungal and bacterial diseases may also occur. Its toxic sap calls for care during handling. Wear gloves when working with the plant, and keep sap off skin. The supplied evidence gives no edible use for this species.