Celtis australis aka European Hackberry

Celtis australis is a deciduous tree in the Cannabaceae family. Common names include European hackberry and European nettle tree. Its native range runs from the Mediterranean to northern Iran. It grows in hedges, on banks, and in sandy places. Gardeners plant it for shade, street use, and wildlife.

This fast-growing tree forms a broad, rounded, sometimes uneven crown. Garden heights range from 40–70 feet [12.2–21.3 metres]. Its spread reaches 40–50 feet [12.2–15.2 metres]. RHS describes trees reaching about 66 feet [20 metres]. It often has one trunk, with branches that droop. The light grey bark is smooth with some wart-like bumps. Thin young twigs are green or brown. Alternate, simple leaves have an oval shape and sharp teeth. Their dark green colour fades to pale yellow in autumn. The leaves then fall, leaving the branch shape on view.

Small green to yellow-green flowers appear from April to May. They offer little show compared with the crown and leaves. Small clusters of round fruits follow the flowers. These turn purple-black and reach about 0.4 inches across. Birds and other wildlife eat them, including squirrels. People can eat the fruit raw, though its flesh is mealy. Each fruit holds one large seed. The seeds are edible raw or cooked and yield oil. PFAF lists no known hazards, but gives no pet-specific safety evidence.

Grow this tree in full sun and fertile, well-drained soil. It accepts clay, loam, sand, and chalk. It also tolerates acid, neutral, and alkaline soils. Moist soil supports faster growth, but the tree withstands drought. Hot summers suit it best in the UK. Sources rate it for USDA zones 6–9 and RHS H6. It tolerates urban sites and has moderate resistance to salt spray. Its wood serves for tool handles, turned goods, and fuel. The bark yields yellow dye, while thin shoots make walking sticks. PFAF also records traditional medicinal uses of leaves and fruit.

Pests and diseases seldom cause major trouble, though problems can occur. Watch for lacebugs, scale, mildew, leaf spots, and root rot. Witches' broom can form dense, twisted clusters of twigs. Large surface roots may lift paving and hinder mowing. Fallen fruit and leaves create litter; fruit can cause slips. Weak branch structure can lead to breakage, so structural pruning matters. Trunk wounds may also lead to internal decay.