The caper shrub has long branches that sprawl over the ground, trail down walls or slopes, or arch gracefully to form 3- to 5-foot mounds up to 10 feet across. Nearly round 2-inch leaves are dark green and fleshy. Most fall in winter, when the shrub is dormant. Temperatures in the mid-teens will not harm the plant, although branches may freeze nearly to the ground. From spring to fall, buds form in each leaf joint. If not harvested for pickling, these open into attractive 2- to 3 -inch flowers with four crepe-like white petals. Each flower lasts only half a day.
To harvest, pick over plants every day and remove buds. Small buds are considered best in flavor. A 3-foot-wide plant will probably yield 25 buds a day throughout warm weather, though production may slow for a few days, then resume,
The easiest way to pickle the buds is to drop them into a jar partially filled with vinegar and let them steep in the refrigerator for at least two weeks or until the flavor seems right (raw capers are unpalatable). Add salt to the vinegar to taste. Another technique calls for drying the capers first, then pickling. You can also mix caper buds with salt overnight, then put them in vinegar.
Plants are easy to grow in any well-drained soil, even the poorest and rockiest. Once established, they need little water (only natural rainfall near the coast) and appreciate full sun. To grow capers from seed, sow in pots of planting mix indoors or in a warm outdoor location. Cover seed to three times its depth, water well, then wait. Germination is slow and irregular. Seedlings may appear in three weeks or much later. Growth is also tentative at first but speeds up as plants age. The first crop of buds is slight, usually appearing the second year after sowing.
Species: Capparis spinosa L. (syn. Capparis rupestris)
also Capparis ovata Desf.
Family: Capparidaceae (or Capparaceae)
Capers of commerce are immature flower buds which have been pickled in vinegar or preserved in granular salt. Semi-mature fruits (caper berries) and young shoots with small leaves may also be pickled for use as a condiment.
Capers have a sharp piquant flavor and add pungency, a peculiar aroma and saltiness to comestibles such as pasta sauces, pizza, fish, meats and salads. The flavor of caper may be described as being similar to that of mustard and black pepper. In fact, the caper strong flavor comes from mustard oil: methyl isothiocyanate (released from glucocapparin molecules) arising from crushed plant tissues.
Capers make an important contribution to the pantheon of classic Mediterranean flavors that include: olives, rucola (argula, or garden rocket), anchovies and artichokes.
Tender young shoots including immature small leaves may also be eaten as a vegetable, or pickled. More rarely, mature and semi-mature fruits are eaten as a cooked vegetable. Additionally, ash from burned caper roots has been used as a source of salt.
Capers are said to reduce flatulence and to be anti-rheumatic in effect. In ayurvedeic medicine capers (Capers=Himsra) are recorded as hepatic stimulants and protectors, improving liver function. Capers have reported uses for arteriosclerosis, as diuretics, kidney disinfectants, vermifuges and tonics. Infusions and decoctions from caper root bark have been traditionally used for dropsy, anemia, arthritis and gout. Capers contain considerable amounts of the anti-oxidant bioflavinoid rutin.
Caper extracts and pulps have been used in cosmetics, but there has been reported contact dermatitis and sensitivity from their use.
There is a strong association between the caper bush and oceans and seas. Capparis spinosa is said to be native to the Mediterranean basin, but its range stretches from the Atlantic coasts of the Canary Islands and Morocco to the Black Sea to the Crimea and Armenia, and eastward to the Caspian Sea and into Iran. Capers probably originated from dry regions in west or central Asia. Known and used for millennia, capers were mentioned by Dioscorides as being a marketable product of the ancient Greeks. The Roman scholar, Pliny the Elder, also mentions capers.
Ecology and Habit:
Dry heat and intense sunlight make the preferred environment for caper plants. Plants are productive in zones having 350 mm annual precipitation (falling mostly in winter and spring months) and easily survive summertime temperatures higher than 40°C (105°F). However, caper is a cold tender plant and has a temperature hardiness range similar to the olive tree (-8°C, 18°F.)
Where native, plants grow spontaneously in cracks and crevices of rocks and stonewalls. Plants grow well in nutrient poor sharply drained gravelly soils. Mature plants develop large extensive root systems that penetrate deeply into the earth. Capers are salt-tolerant and flourish along shores within sea-spray zones.
Caper plants are small shrubs, and may reach about one meter upright. However, uncultivated caper plants are more often seen hanging, draped and sprawling as they scramble over soil and rocks. The caper’s vegetative canopy covers soil surfaces which help to conserve soil water reserves. Leaf stipules may be formed into spines. Flowers are born on first-year branches.
Botany and Taxonomy:
Family: Capparidaceae (or alternatively Capparaceae)
The genus Cleome (Spider flower) is sometimes included in the Capparidaceae, but more modern interpretations place Cleome into its own family, the Cleomaceae. Phylogenists agree that the Brassicaceae (Cruciferae) and the Capparidaceae are closely related families.
C3 physiology has been recorded for the genus Capparis. Pollination is by insects. Mature fruits are dehiscent.
Locally, capers are collected from wild plants within their natural range. European sources are Spain (Almeria, Grenada and Balearic Islands), France (Provence), and Italy (especially Sicily and the Aeolian island of Salina and the Mediterranean island of Pantelleria). Capers are also cultivated in Dalmatia and Greece. Other areas of production include Algeria, Egypt, Morocco, Tunisia, Asia Minor, Cyprus and the Levant, the coastal areas of the Black Sea, and Iran.
Areas with intensive caper cultivation production include Spain (2,600 hectares) and Italy (1000 hectares). Statistics for France, Greece, North African countries and Asia are not reported.
In Colombia, it has been reported that buds of one species of Cassia, pickled in sour vinegar with cloves, have been falsely sold as capers.
Crop Culture & Propagation:
Plants are grown from seed and by vegetative cuttings.
Caper seeds are miniscule and are slow to nurture into transplantable seedlings. Fresh caper seeds germinate readily – but only in low percentages. Dried seeds become dormant and are notably difficult to germinate and therefore require extra measures to grow. Dried seeds should be initially immersed in warm water (40°C or 105°F) and then let soak for 1 day. Seeds should be wrapped in a moist cloth, placed in a sealed glass jar and kept in the refrigerator for 2 – 3 months. After refrigeration, soak the seeds again in warm water overnight. Plant the seeds about 1 cm deep in a loose well-drained soil media. Young caper plants can be grown in a greenhouse (preferable minimum temperature of 10°C or 50°F).
Collect cuttings in February, March or April. Use stems from the basal portions, greater than 1 cm diameter and 8 cm in length with 6-10 buds. Use a loose well-drained media with bottom heat. A dip in an IBA solution of 1.5 to 3.0 ppm is recommended (15 seconds). A 70% rooting percentage would be considered good.
Transplanting is carried out during the wet winter and spring periods, and first-year plants are mulched with stones.
In Italy, plants are spaced 2 to 2.5 meters apart (depending on the roughness of the topography; about 2,000 plants per hectare). A full yield is expected in 3 to 4 years. Plants are pruned back in winter to remove dead wood and water sprouts. Pruning is crucial to high production. Heavy branch pruning is necessary, as flower buds arise on one-year-old branches. Three-year-old plants will yield 1 to 3 kilograms of caper flower buds per plant.
Grown from seed, in California caper bushes reportedly begin to flower in the fourth year, however Italian sources report some flowering from first year transplants.
Caper plantings will last 20 to 30 years.
The unopened flower buds should be picked on a dry days. Harvesting is carried out regularly throughout the growing season. In Southern Italy, caper flower buds are collected by hand about every 8 to 12 days, resulting in 9 -12 harvest times per season.
Capers are preserved either in vinegar or under layers of salt in a jar. Raw capers are bland flavored and need to be cured to develop their piquant flavor. In Italy, capers are graded on a scale from ‘7’ to ’16’, which indicates their size in millimeters. Mechanized screens are used to sort the various sized capers after being handpicked from the hillsides.
In French speaking countries, capers are graded using the terms ‘Nonpareilles’ and ‘Surfines’. Capers under a centimeter diameter are considered more valuable than the larger Capucines and Communes (up to one and a half centimeters of diameters).
Capers in vinegar are traditionally packaged in tall narrow glass bottles.
Caper fruits (caperberry, capperone, or taperone) may be used in making caper flavored sauces, or sometimes pickled for eating like small gherkins.
Cultivars and Varieties:
Varieties have been selected for spinelessness, round firm buds, and flavor. High-yielding caper plants and types with short and uniform flowering periods have not been developed.
‘senza spina’ Italian selection or form without stipular spines.
‘spinosa comune’ – Italian form with stipular spines
‘inermis’ – without stipular spines.
‘josephine’ – one of the better Mediterranean selections
‘dolce di Filicudi e Alicudi’ – From the Aeolian Archipelago
‘nuciddara’ or ‘nucidda’
‘nocellana’- spineless, with globose buds, mustard-green color, and strong aroma
‘testa di lucertola’
‘tondino’ – grown on the island of Pantelleria
Diseases and Pests:
Viruses are transmitted by mechanical inoculation; by grafting, and vegetative propagation of cultivated varieties. Certain insect pests may also be vectors.
Two viruses: Caper Latent Carlavirus, and Caper Vein Yellowing Virus have been reported in Puglia, Italy
Albugo capparidis De By
Aschochyta capparidis (Cast.) Sacc.
Botrytis – gray mold
Camarosporium suseganense Sacc. et Speg.
Cercospora capparidis Sacc.
Cloeosporium hians Peck et Sacc.
Hendersonia rupestrisSacc. et Speg.
Phyllosticta capparidisSacc. et Speg.
Insects & Pests:
Acalles barbarus Lucas – a weevil that attacks roots
Asphondylia capparis Rubs. – a dipterian (Cecidomyiidae) that disfigures flower buds.
Calocoris memoralis Sacc.
Cydia capparidana Zeller – a lepidopteran that disfigures flower buds.
Eurydema ventralis Kolen