A caper bush with a flower, buds and a fruit.
A caper bush with a flower, flower buds and a fruit.

Capers, also called Caper Bush, Flinders Rose

Capparis spinosa inermis

Origin:

Mainly found in the vicinity of the Mediterranean Sea, but also in other parts of the world. The genetic origin is uncertain.

Climate:

Mediterranean type climate, semiarid or arid; capers grow well in Perth, plus areas as far north as Geraldton, and in the South West. Plants will tolerate temperatures above 40°C. Frost may affect the growth of young plants.

Plant Description:

The small, elongated, roundish, leathery leaves are green on the top and silverish underneath. The plant is slow to establish and grows as a prostrate bush, to 1.3m high. Plants can live for 20 or 30 years.

Relatives:

There are hundreds of species in the Capparis genus. The species name spinosa means 'thorny', and most of them have thorns. However, the variety name inermis means 'thornless'. There are several native Australian Capparis species: C. michellii; C. nobillis; and C. umbonata.

Soils:

Capers can be grown in a wide range of soils, including poor soils, providing these are well drained.  The plant has some drought and salt tolerance. Capers have a deep taproot and require little watering. There are caper bushes growing on the face of the 57m high Western Wall in Jerusalem, sprouting between large limestone blocks.

Propagation:

Fresh seed can be obtained from caper berries and should germinate readily. They are miniscule in size. Old seed can also be purchased from eastern States seed companies. To germinate old seed, freeze the seed in sand for two weeks. Plants can also be grown from cuttings (with difficulty). Plants are best purchased from nurseries.

Cultivars:

Varieties have been selected for spinelessness, round firm buds, flavour, high yield and coordinated flowering periods. It is probably very difficult to find these in Australia.

Flowering and Pollination:

The attractive, fragrant white flowers are about 7cm wide, with prominent mauve stamens and a long stigma. Most are perfect, but some are male. Flowering is from late October to May in Trigg. Insects, especially bees, pollinate the flowers.

Cultivation:

Transplanting should be done in wet weather. First-year plants are mulched with stones. Plants are spaced 2m to 2.5m apart.

Wind Tolerance:

Capers have good wind tolerance.

Pruning:

Pruning is crucial to high production. Plants are pruned back in winter to remove dead wood and watersprouts. Heavy branch pruning is necessary, as flower buds arise on one-year-old branches.

The Fruit:

It is the immature green flower buds that are mainly used. If they are not picked, the flower buds develop into flowers and eventually into small, elongated, fruits. These are also edible and have a milder taste than the immature flower buds.

Fruit Production and Harvesting:

Plants begin producing a harvest after about 4 years. Immature green flower buds are 10-17 mm wide. They may be picked by hand on a dry day, every 2-4 days in Perth. If not picked, the flower buds develop into flowers and eventually into small, elongated, fruits. These are also edible and have a milder taste than the immature flower buds. A mature plant may produce 3 kg of flower buds per plant.

Fruit Uses:

Caper fruit buds and berries are best stored in white vinegar. They are used as a garnish and in salads and salad dressings. They have a sharp, piquant flavour, releasing mustard oil. Mature caper fruits and caper leaves can also be pickled.

Pests and Diseases:

None have been noticed in Trigg, Perth.

Comments:

Capers grow well in Perth home gardens. Picking and pruning must be regular. One plant should be enough for a family’s needs. Plus, they are attractive and hardy, requiring very little water, once established. Bushes can be planted on slopes to control erosion.