Cultivation and Uses
USDA hardiness zones: 8b-11. The plant dies to the ground in freezing temperatures
and its roots die at 18°F (-7.8°C).
Heat tolerant: Yes.
Drought tolerant: Yes.
Sun: Full sun. This plant does poorly in shade.
Planting: Caper Bush grows on rocks and in hilly, rocky soil. It needs a very dry
summer environment and grows better in a high crevice on a rock wall than in a container
unless the container is very well draining.
The rocky spaces it prefers are the equivalent of a raised garden bed.
It may be necessary, during summer and fall, to grow this plant under a clear plastic
panel that keeps out all water and rain but allows free air flow.
Space the plants 7-9' (2.1-2.7m) apart if used for caper production.
Soil: Very well draining, dry, low in organic content, pH 5.6-8.5
(slightly acidic to alkaline). It grows best in slightly acidic to slightly alkaline soil.
This plant is salt tolerant. Fertilization is unnecessary.
Water after becoming established: Deep water
once a month except during the four hottest months when it should receive no water or rain.
It does not like summer rain and easily dies from being overwatered. In its native region,
rain occurs mostly in winter and spring.
Mulch: Use rock or stone mulch only, in the first year only, when freezing
temperatures are predicted.
Prune: Remove dead wood in winter, but do not prune in the first year. Flower buds
occur on one year old branches. Heavy pruning of old branches improves productivity.
Litter: The entire plant may die to the ground during a freeze.
Propagation: Fresh seed sprout easily but dried seed have a low germination rate.
To germinate dried seeds:
[1] Place them in warm water for 12 hours, allowing the water to cool naturally to room
temperature.
[2] Fold them into a moist paper towel, seal the towel in a plastic freezer bag,
and refrigerate for 2-3 months.
[3] Remove from the refrigerator and soak in water as in step one.
[4] Plant the seeds in small pots with seed starter soil and keep the soil moist
in a warm, daytime bright environment. They should sprout within 1-3 months. A seed starter
kit with a timed grow lamp and a heater pad (if necessary) is ideal for this stage.
[5] Transplant the seedlings outside when they are 3-5" (7.6-12.7cm) tall, adding
mycorrhizal fungi to the soil.
If seedlings are crowded in the pot, cut off the weaker seedlings at the ground using
scissors. Do not pull seedlings out because that will damage roots of the others.
[6] Transition the seedlings to their new, hot and dry environment by providing shade and
moisture at first, then gradually withdrawing shade and moisture as the plant adjusts.
Seedlings will not flower for 1-4 years, depending on the cultivar.
This plant can be grown from both softwood and hardwood cuttings.
Hardwood cuttings should be at least 1/4" (6-7mm) in diameter.
Softwood cuttings must be from the base of the stem. Rooting solution is recommended.
The success rate of cuttings is 50-70%. Cuttings may take 1-3 years to flower.
Uses: The unopened flower buds, berries, and young leaves are pickled in salt or
vinegar, to remove bitterness, and used as seasoning or a garnish. The flavor of the pickled
flower buds (capers) has been described as mustard with black pepper. Young leaves and stems
are also boiled and eaten.
This xeric plant is also used to prevent soil erosion. It can be used as an ornamental
plant hanging from a rock wall or other structure.