Capparis spinosa aka Flinders Rose

Capparis spinosa, or caper, is a shrub. It belongs to the Capparaceae family. It grows wild in southern Europe, parts of Africa, and Asia. Its native range also reaches Australia and islands of the Pacific. It grows on old walls, cliffs, and hot, rocky slopes. People have used it for food and medicine since the Bronze Age. Growers still raise it for food and for gardens.

The shrub can grow upright or spread across the ground. RHS gives its garden height and spread as 1.6–3.3 feet [0.5–1 metre]. Useful Tropical Plants gives heights up to 6.6 feet [2 metres]. Its branches can grow 13.1 feet [4 metres] long. Some plants have many thorns, while others have none. Deep roots spread through the ground. The leaves are round and grey-green. They reach about 1.6 inches across. Sources differ on whether it keeps its leaves. RHS calls it deciduous, which means it sheds its leaves. Others say it is evergreen and keeps its leaves.

The flowers have four white petals and many long stamens. These flower parts range from white or pink to purple. Missouri Botanical Garden gives a bloom time of May to September. The flowers have scent and add colour to dry gardens. The fruits look like olives and grow on long stalks. People keep the closed flower buds in salt or vinegar. These buds are the capers used in cooking. People also preserve and eat the fruits, called caperberries.

Give caper full sun and shelter from harsh exposure. RHS lists sandy or loamy soil that drains well. It accepts acid, neutral, or alkaline soil. Missouri Botanical Garden says it copes with drought and shallow, rocky ground. Sources differ on how much cold it can take. RHS rates it H1C, with outdoor summer growth in Britain. Missouri Botanical Garden lists USDA zones 8–10. Useful Tropical Plants says dormant plants can cope with brief frost. For growth under glass, RHS advises peat-free, loam-based compost. Add extra grit to this mix. Give modest amounts of water during growth and little in winter. Use a high-potash feed each month in the growing season.

Caper suits pots, patios, and glasshouses. It also suits dry, sunny sites in gardens. People use it to help hold soil and mark boundaries. Missouri Botanical Garden says it resists deer and rabbits. Few pests or diseases cause serious problems, though mealybugs may attack. Seeds can be slow to sprout, with uneven results. RHS advises soaking the seeds before sowing them. Caper extracts and pulp in cosmetics can cause skin reactions. This warning is about skin contact, not the preserved foods.