Euphorbia dendroides aka Woody Spurge

Euphorbia dendroides, or tree spurge, belongs to the spurge family. This semi-succulent shrub comes from the Mediterranean region. It grows on open, rocky slopes near the coast. Many of these sites have lime-rich ground. Garden plants reach about 5–8 feet [1.5–2.5 metres] tall and wide. Some form small trees reaching 10 feet [3 metres]. Its many branches build a rounded crown with age. Plants take about five to ten years to mature.

The woody stems have red bark and release white sap. Young branches hold some water, while older bases become corky. Narrow green leaves grow in groups near the branch tips. Leaf colour and leaf fall vary with the growing conditions. RHS describes red and orange autumn leaves before they drop. LLIFLE records red spring leaves and leaf loss during summer drought. In its Mediterranean habitat, new leaves emerge in autumn. Growth then continues through the wetter winter months.

Green-yellow bracts surround the small flowers at the stem tips. These clusters appear in spring, with a peak around mid-March. The flower units, called cyathia, contain male and female flowers. Nectar glands start yellow and turn red as they age. Wind carries the pollen, though insects and lizards also visit. After flowering, stems fork below the old flower heads. Ripe fruits burst open and throw seeds from the plant. Ants also move seeds, drawn by their fleshy attachments.

Give this shrub full sun and a sheltered, frost-free site. It needs soil that drains well and tolerates dry spells. Chalk, loam and sand suit it across a broad pH range. RHS rates it H2: it tolerates cool conditions but not freezing. Containers allow growers to keep it under cover in cold weather. A greenhouse, conservatory or large sunny room can house mature plants. Water moderately in winter, without leaving the roots in wet soil. Prolonged wetness can lead to root rot.

Its rounded shape makes it useful as a bold specimen. It suits Mediterranean-style gardens and patio pots where frost protection is possible. Little pruning is needed to keep its natural dome. Cuttings can be taken in spring or early summer. RHS reports few routine pest or disease problems. The plant can harm both people and pets if eaten. It can also irritate skin and eyes. Wear gloves and other protective gear when handling it.