Capers, those small, flavorful additions to many dishes, originate from the caper plant, Capparis spinosa. This plant offers a unique opportunity for home gardeners to cultivate a culinary ingredient directly from their landscape.
Understanding the Caper Plant
The caper plant, Capparis spinosa, is a shrub-like perennial known for its sprawling or upright growth habit, reaching about 2-3 feet tall and 3-6 feet wide. Native to the Mediterranean region and parts of Asia, it thrives in hot, arid conditions, often found growing in rocky, gravelly soils, and even old walls. This plant is characterized by its glossy green leaves and often thorny stems, though spineless varieties exist. Capers are the unopened flower buds, while the larger, oblong fruits that develop if the buds are left unpicked are called caper berries.
Cultivating Caper Plants
Establishing a caper plant begins with selecting a suitable location that mimics its native environment. These plants require full sun, receiving at least six to eight hours of direct sunlight daily. They flourish in well-draining soil, preferring sandy, gravelly, or even poor, nutrient-deficient conditions. A neutral to slightly alkaline pH is suitable.
Caper plants are well-suited to warm, dry climates, demonstrating drought tolerance once established. They can withstand summer temperatures exceeding 105°F (41°C) but are sensitive to cold, hardy only down to about 18°F (-8°C). In regions with colder winters, growing capers in containers allows them to be moved indoors when temperatures drop. Propagation can be achieved through seeds, which often require cold stratification and soaking for germination, or through stem cuttings.
Caring for Caper Plants
Once established, caper plants require minimal maintenance. During their initial two years, consistent watering helps establish a robust root system. Mature plants are highly drought-tolerant, needing infrequent watering; allow the soil to dry out significantly between waterings to prevent root rot.
Pruning encourages the production of more flower buds. Hard pruning in late winter or early spring, cutting back stems to a few inches from the ground, promotes new growth where buds will form. While established caper plants thrive in infertile soil, young plants may benefit from minimal feeding with a slow-release fertilizer during spring and summer. Capers are also resistant to many common pests and diseases.
Harvesting and Curing Capers
Harvesting capers involves collecting the unopened flower buds, typically from late spring through early autumn. The optimal time to pick these buds is in the early morning, before the heat of the day causes them to begin opening. Buds should be dark green, tight, and at least 1/4-inch wide for the best quality and flavor. Unpicked buds will open into attractive white-to-pinkish-white flowers with long purple stamens, which then develop into caper berries.
Caper berries are also edible and can be harvested once they are firm and mature. Unlike the buds, caper berries are typically harvested later in the season. Fresh caper buds and berries are inedible due to their bitter taste and require a curing process to develop their characteristic piquant flavor. This process involves either dry salting or brining them in a solution of salt, water, and often vinegar. The curing process releases mustard oil compounds, transforming their flavor profile into the tangy, savory condiment enjoyed in Mediterranean cuisine.
Common Challenges in Growing Capers
Gardeners cultivating caper plants may encounter issues related to environmental conditions. Insufficient sunlight leads to poor flowering, as caper plants require at least six hours of direct sun daily for optimal bud production. If the plant is not flowering, relocating it to a sunnier spot can resolve this. Overly rich soil can also hinder flowering, as these plants perform best in lean, well-draining conditions.
Overwatering can cause root rot, manifesting as yellowing leaves or wilting. Caper plants are drought-tolerant, so allow the soil to dry out between waterings. Conversely, underwatering can also cause wilting and dry foliage, particularly during extreme heat. Signs of insufficient light can include leggy growth, smaller new leaves, or a general lack of vigor. Adjusting light exposure and ensuring proper drainage are important for addressing these challenges.