Cinnamon is a spice derived from the inner bark of trees belonging to the genus Cinnamomum. Outdoor cultivation in the United States is highly restricted due to the tree’s specific and demanding tropical needs. Successfully growing cinnamon requires replicating an equatorial environment, making it a challenging but achievable endeavor for dedicated growers in a few select areas. Producing a harvestable crop depends entirely on maintaining precise environmental conditions year-round.
Essential Climate Requirements
The Cinnamomum verum tree, which yields high-quality Ceylon or “true” cinnamon, requires a consistently warm and wet climate to thrive. Ideal growing temperatures range between 75°F and 90°F. The tree is extremely sensitive to cold; a temperature drop below 50°F halts growth, and any exposure to frost will kill the plant entirely.
Cinnamon also requires high moisture, both in the air and the soil. Optimal relative humidity should be maintained above 70% to mimic its native environment and prevent water stress. It needs substantial annual rainfall, ideally between 50 and 138 inches, or consistent supplemental irrigation. This means the tree can only be grown outdoors in the most tropical USDA Hardiness Zones, specifically Zones 10 through 12.
Feasible Growing Regions in the US
The US mainland’s climate restricts outdoor cultivation to very narrow geographic areas that fall within tropical hardiness zones. The most reliable location for growing cinnamon is Hawaii, which naturally provides the required year-round warmth, high humidity, and consistent rainfall. The US territories of Puerto Rico and the US Virgin Islands also offer ideal tropical conditions for the tree’s establishment.
On the continental US, the only feasible region is the southernmost tip of Florida, including the Florida Keys and limited areas of Zone 10b and 11. Even here, growers must be vigilant, as occasional cold snaps necessitate protective measures like covering the trees. In less suitable areas, such as Southern California, the species can be grown in containers and moved indoors, but reaching a size large enough for a productive bark harvest is significantly more difficult.
Practical Cultivation and Care
Successfully growing a cinnamon tree requires attention to soil composition and water management. The tree needs a well-draining, sandy loam soil that is slightly acidic, ideally with a pH between 5.5 and 6.5. This composition allows for consistent moisture retention without becoming waterlogged, which can lead to fatal root rot.
The plant benefits from full sun exposure once mature, but young saplings should be protected from harsh afternoon sun with partial shade to prevent leaf scorch. Consistent irrigation is required to ensure the soil remains moist, especially during dry periods. Pruning is a preparatory technique for bark production, as the tree is maintained as a multi-stemmed bush rather than a single trunk.
Growers must also watch for pests like mealybugs and spider mites, which can infest the foliage, and diseases common in high-humidity environments. Fungal infections, such as leaf spot and rough bark disease, are threats that can be managed with treatments like neem oil or a copper-based fungicide. The most commonly cultivated variety in home settings is Cinnamomum verum, or Ceylon cinnamon, which has a superior, milder flavor compared to the more common Cinnamomum cassia.
Harvesting and Curing Cinnamon Bark
Cinnamon is typically ready for its first harvest approximately two to three years after planting, when stems reach a diameter of about one to two inches. The process begins with coppicing, where mature stems are cut close to the ground (about 12 inches high) to encourage the growth of new, straight shoots. This practice ensures a continuous supply of bark from the regenerating stump.
The stems are harvested immediately following a rainy period, as high moisture content makes the bark more pliable and easier to peel. The rough, corky outer bark (epidermis) is first scraped away with a knife to expose the inner, fragrant layer. A brass rod is then often used to rub the inner bark, loosening the cambium layer that contains the spice compounds.
The thin, moist strips of inner bark are carefully peeled off and naturally curl into tubes as they dry. These are known as quills. For true Ceylon cinnamon, smaller pieces are often rolled inside larger ones to create compound quills with multiple fine layers. These quills must be dried in a shaded, ventilated area for several days to prevent cracking and preserve the volatile oils that give cinnamon its flavor. Cassia, by contrast, is harvested as a single, thicker layer that curls into a hollow tube.