Growing Piquant capers
The common caper (Capparis spinosa) is cultivated as a small-scale commercial crop in Sicily, southern France and the southern United States, and it is capers from these crops which you buy pickled in small jars for your pizzas and sauces. But if you have some room to spare in your cool greenhouse, you might like to try and grow one or two of these small, spiny, evergreen shrubs.
The edible part of the caper plant is the unopened flower bud; these are gathered and pickled in wine vinegar. Although you will never see the flowers, they are extremely beautiful, with white petals and rose-purple stamens. The caper plant is not difficult to cultivate so long as you remember that it is a sun-lover and must have plenty of sunlight throughout the year for a plentiful supply of buds. It is not at all frost-tolerant, so you must be able to maintain a winter temperature above freezing, 5°C (40°F) at least.
Capers are grown from seed, usually available from the leading nurseries. Sow the seed in mid-spring in a tray filled with John Innes seed. Cover the tray with glass or heavy polythene and keep it in a warm place. For germination to occur, the temperature should be maintained at no lower than 18°C (64°F), higher if possible. Remove the cover after germination, usually in about three weeks.
Move the young plants into pots singly when they are about 5 cm (2”) high. Fill 7.5 cm (3”) pots with John Innes potting compost No. 1, and place one plant in each pot. Be sure the pots have good drainage, and never allow theto become waterlogged or to dry out.
As the plants develop, pot them on twice more, first into 12.5 cm (5”) pots, and finally into 20 cm (8”) pots. The potting compost should be increased in strength as well; use John Innes No. 2 for the first move and John Innes No. 3 for the final pot.
The shrubs will branch out naturally as they grow, but you can also help this along by occasionally pinching back the tips of the shoots. Keep the plants well watered. Little water will be required between late autumn and early spring, when the plants rest and lose a few of their leaves, and feeding is not necessary at all at this time. When growth begins again in mid-spring, prune back long shoots to leave two or three buds only and increase the watering. Feeding can start towards the end of late spring.
Aphids may attack the tips of the shoots and young leaves, so if they are present in your greenhouse, a spraying with derris will be beneficial.
You can propogate capers fromduring the summer months. Cut the tips off new, young shoots with three or four leaves and insert three or four round the edge of 8 cm pots filled with a mixture of moist peat and sand. Cover the pots with blown-up, clear plastic bags, keep the compost moist, and put them in a warm, 18-21°C (65-70°F), shaded place. It is wise to replace the old plants every few years.
Capers will not ‘crop’ until they are two years old. The shrubs will begin to flower in late spring. Check the plants daily for mature but still unopened flower buds. Gather them each morning and immediately pickle them in salt and strong wine vinegar.