Calicotome spinosa aka Spiny Broom

Calicotome spinosa is a deciduous shrub in the pea family, Fabaceae. Its range lies around the western Mediterranean in Europe and North Africa. Records include Spain, France, Italy, Algeria, and Libya. It also occurs on several islands, including Corsica and Sardinia. Other records include Sicily and the Balearic Islands. It is not native to Britain or Ireland. In the wild, it grows in dry, stony coastal scrub. It can become common where people have cleared woodland.

The shrub reaches about 10 feet [3 metres] in height. It loses its leaves rather than keeping them year-round. Flowers appear from May to July. Each flower has both male and female organs. Insects pollinate the blooms. These traits make its flowering season relevant to insect visitors. The supplied sources give no further details about its leaves, bark, or fruit.

Grow this shrub in full sun, with very good drainage. It does not grow in shade. It accepts sandy, loamy, and clay soils when drainage is suitable. Soil may be mildly acid, neutral, or mildly alkaline. It can grow in dry or moist ground. Moisture alone is therefore not the main limit described here. Drainage remains a key need across these soil types. PFAF lists USDA hardiness zones 7–10. It also reports tolerance of roughly −5 to −10°C with excellent drainage. The same source warns against growing it in colder British areas.

Choose its final site while the plant is young. Its roots do not respond well to disturbance. Early planting avoids moving an older shrub later. PFAF lists uses in low hedges and sunny woodland edges. These uses suit places with open light rather than overhead shade. The plant also forms a partnership with soil bacteria. The bacteria live in root nodules and fix nitrogen from the air. The shrub uses some of that nitrogen. Nearby plants may also gain some benefit.

PFAF records no known food or medicinal uses for this species. Its food and medicinal ratings are both zero. It lists no known hazards, but that does not establish safety for eating. The supplied evidence gives no specific information on pet toxicity. It also gives no named pests or diseases to watch for. The clearest care concerns are poor drainage, cold, and root disturbance.