Caper Bush Seeds (Capparis spinosa) Perennial

Grow the Mediterranean's most sought-after delicacy! This hardy, sun-loving perennial yields prized savory buds for gourmet curing. Once established, these drought-tolerant bushes provide decades of elegant blooms and flavorful harvests. Hardiness zones 9-11. 40 seeds minimum Start indoors for best results. Seeds require cold stratification for successful germination. Sow stratified seeds 1/4" deep in a mix of 50% potting soil, 25% perlite, and 25% sand. Store in warm spot (70–85°F) with moist soil. Germination may take 3 weeks to 3 months.  See Annie’s Caper Bush Growing Guide for detailed instructions. Mature plants reach 2 to 3 feet in high, spreading 3 to 10 feet wide. Caper Bush Growing Guide 1. Germination: Overcoming the Challenge Caper seeds are tough to germinate due to their hard, dormant coats. Initial Soak: Submerge seeds in warm water (110–115°F) for 12–24 hours. Cold Stratification: Wrap soaked seeds in a damp paper towel, seal in a bag, and refrigerate (40°F) for 65–70 days. Second Soak: After refrigeration, soak seeds again in warm water for 24 hours. Scarification (Optional): Lightly sand the seed coat to aid water absorption. Sowing: Plant seeds 1/4–1/2 inch deep in a mix of 50% potting soil, 25% perlite, and 25% sand. Care: Keep soil moist and warm (70–85°F). Germination may take 3 weeks to 3 months. 2. Early Care & Transplanting Thinning: Snip weaker seedlings with scissors to avoid disturbing sensitive roots. Hardening Off: When seedlings reach 3–5 inches, move them to 1-gallon pots. Gradually acclimate them to outdoor conditions over 2–3 weeks using the plastic bag method. Final Site: Choose a sunny location (6–8+ hours of sunlight) with excellent drainage, such as rocky walls or raised beds. 3. Soil, Fertilizer & Maintenance Soil Chemistry: Use alkaline soil (pH 7.5–8.5). Amend acidic soil with garden lime or crushed oyster shells. Fertilization: Apply a low-nitrogen, high-potassium/phosphorus fertilizer (e.g., 5-10-10 or 16-16-16) 2–3 times during spring and summer. Pruning: Flowers grow on one-year-old wood. After the plant is 3 years old, prune heavily in late winter to encourage new growth. 4. Companion Plants Capers thrive with other Mediterranean plants that love heat and dry, rocky soil: Herbs: Rosemary, thyme, sage. Flowers: Lavender, rock rose (Cistus), California poppy. Succulents: Aloe vera, sedum (stonecrop). 5. Troubleshooting Root Rot: Caused by overwatering or clay soil. Let the top 2 inches of soil dry completely before watering. Pests: Cabbage White Butterfly caterpillars may attack leaves; use organic Bt spray or hand-pick them. Chlorosis (Yellow Leaves): Indicates acidic soil or iron deficiency. Use chelated iron and check soil pH. 6. Harvesting & Curing Capers: Harvest unopened flower buds early in the morning when they’re tight and dark green. Smaller buds are more flavorful. Caperberries: Allow flowers to bloom and die to produce caperberries, which can also be pickled. Curing: Capers must be cured before eating. Soak rinsed buds in coarse sea salt for 1–2 weeks or brine them in equal parts water and white wine vinegar for at least 3 days. Plastic Bag Hardening-Off Technique The plastic bag method is a hardening-off technique that eases seedlings from indoor conditions to outdoor environments. Acting as a temporary greenhouse, it stabilizes humidity and protects plants from wind and temperature changes. Summary of the Method This method focuses on managing transpiration, as indoor plants develop a thin waxy cuticle and lack the ability to quickly close their stomata. Preparation: Place the seedling in a clear plastic bag, ensuring it doesn’t touch the foliage. Support: Use stakes to prevent condensation from causing rot. Ventilation: Loosely tie the bag or add air holes for gas exchange. Exposure: Start with shaded outdoor placement for a few hours. Gradual Removal: Over 5–7 days, increase exposure and open the bag until it’s fully removed. Caution: Avoid direct sunlight, as the greenhouse effect can overheat and damage plants. Always start in full shade or on cloudy days. Best That Benefit from This Method Nightshades: Tomatoes, peppers, eggplants (sensitive to humidity drops). Cucurbits: Cucumbers, melons, squash (large leaves lose moisture quickly). Tender Herbs: Basil, cilantro, parsley (prone to wind burn). Tropicals: Monsteras, hibiscus, calatheas (mimics jungle humidity). Legumes: Runner and pole beans (need structural protection).