Ecballium elaterium aka Squirting Cucumber

Ecballium elaterium is known as squirting cucumber or exploding cucumber. It belongs to the gourd family, Cucurbitaceae. Its native range spans the Canary Islands and the Mediterranean region. It extends east to southern European Russia and northern Iran. It grows on hot, dry waste ground and roadsides. Other sites include fields, farmland, and stony ground, often near coasts.

This tender perennial often grows as an annual in gardens. Weak stems trail across the ground or clamber over supports. Garden plants reach about 1–1.5 feet [0.30–0.46 metres] tall. They spread to around 3 feet [0.91 metres] wide. RHS gives upper sizes near 1.6 feet [0.5 metres] tall and 3.3 feet [1 metre] wide. The long stems bear stiff hairs and dark, grey-green leaves. Each leaf has five lobes, and the plant sheds its foliage. It has no tendrils, so gardeners must tie stems to supports.

Pale yellow flowers appear from June to August. Plants raised from seed can flower and fruit that year. Hairy, blue-green fruits follow the flowers and mature in autumn. Their oblong shape recalls a small cucumber. Each fruit reaches about 0.25 feet [0.08 metres] long. Ripe fruits respond to touch by shooting seeds far away. Both flowers and fruits add interest to summer plantings.

Give this plant full sun and soil that drains well. Rich soil suits it best, though it tolerates poor ground. It accepts sandy, loamy, or chalky soils across a broad pH range. Moderate soil moisture suits garden growth. Choose a sheltered spot with a south-facing or west-facing aspect. Sow seeds in spring under glass, then plant out after frost. It can cover summer beds or trail along low fences. Tied stems can grow against a trellis, fence, or wall. Regular pruning is not needed. Missouri Botanical Garden lists USDA zones 9–11. RHS rates it H2: it tolerates cool weather, but not freezing.

Serious pest and disease problems are uncommon. Under glass, aphids and red spider mites may cause trouble. The plant can sprawl strongly across nearby ground. Do not treat its cucumber-like fruit as food. PFAF lists no known edible use. RHS warns that eating it can harm people, dogs, and cats. Contact can also irritate skin and eyes. Its fruit juice has a long history of medicinal use. Its harsh effects limit its place in modern herbal medicine.