Carob Tree (Ceratonia siliqua – St John’s-bread) – 10 Seeds
As a Mediterranean species, carob trees (Ceratonia siliqua) are suitable for cultivation within U.S. Department of Agriculture hardiness zones 9 to 11. Mature carob trees produce an abundant crop of large, flat seed pods every other year, which can be harvested and used to propagate new trees. Carob seeds germinate reliably in summer when planted in moist, sterile growing mixture and kept under warm, bright conditions. However, the seeds possess a tough, impermeable outer hull that must be softened before planting to hasten germination.
1 Place the carob pods in a warm, dry place for five to 10 days, or until the seeds rattle when the pods are shaken. Snip off the ends of the pods using sharp, sturdy scissors. Pry open the pod and shake out the seeds.
2 Soak the carob seeds in cool water for one to two hours. Gently rub the seeds to remove the sticky, dried-on pulp. Rinse them thoroughly and lay them flat on a sheet of paper towel for a few hours to dry.
3 Rub the edge of each carob seed with a fine rasp to weaken the hull. Rub gently until the brown outer coat thins and the light inner hull is exposed. Do not rub all the way through the hull since the seed can die.
4 Place the carob seeds in a bowl. Heat water on the stovetop until it begins to boil. Remove the water from the heat and pour it over the seeds until they are covered. Soak the seeds for 24 hours.
5 Prepare growing containers while the carob seeds soak. Fill 4-inch peat pots with a mixture of half sterile compost and half perlite. Pour water onto the mixture until it is saturated. Press the surface lightly to extract the excess moisture.
6 Poke a 1 1/2-inch-deep planting hole in each growing container. Sow one carob seed in each planting hole. Cover the seeds with sterile compost. Drizzle water onto the compost to settle it around the seed.
7 Place the peat pots on a shallow tray near an unshaded, south-facing window that provides eight to 12 hours of natural light daily. Provide supplemental light with a fluorescent lamp, if necessary.
8 Warm the bottom of the peat pots using a propagation mat or heating coil. Maintain a temperature of 70 Fahreneheit at all times during the germination process. Do not lower the temperature since it may cause the seeds to go dormant.
9 Maintain a constant level of light moisture in the growing mixture while the carob seeds germinate. Allow the surface of the growing mixture to dry out slightly before watering again.
10 Watch for germination in 30 to 45 days. Turn the propagation mat off once the seedlings emerge. Decrease watering to prevent a fungal infection called damping-off. Allow the top 1/2 inch of the growing mixture to dry out between waterings.
11 Transplant the carob seedlings once they grow to 3 inches in height. Tear off the bottom of the peat pots and transplant them directly into the garden or into large containers filled with a soil mixture of half loam and half sand.