Native to Asia, cinnamon (genus Cinnamomum) has made its way into the world’s cuisines and gardens. Although derived from the Greek word "kinnamomon," meaning spice, cinnamon cultivars are also grown for their oil and for their camphor. Thriving in U.S. Department of Agriculture plant hardiness zones 8 through 11, this tropical evergreen tree grows best at low altitudes in a moist climate.
Plant Hardiness Zones
Using historical data on the lowest average temperatures in each geographic region, the USDA divided the country up into plant hardiness zones. Separated by 10 degree Fahrenheit temperature differences, each USDA zone tells you the coldest temperature at which a tree or other perennial is likely to survive. For instance, a plant hardy to zone 9a usually does well with winter temperatures of 20 to 25 degrees F, while a tree hardy to zone 8a typically survives temperatures as low as 10 to 15 degrees F. While they are useful starting points in selecting plants, hardiness zones are an inexact science impacted by the forces that create microclimates -- elevation, precipitation, wind and soil. Use hardiness zones as a guideline, but talk with gardening professionals for tips on the cinnamon trees that grow best in your area.
Ceylon Cinnamon Tree
One of the most aromatic and best-known cultivars, Ceylon cinnamon (Cinnamomun zeylanicum) reaches a mature height of 32 to 49 feet when grown as an ornamental or specimen tree. Oblong leaves blush pink at emergence, maturing to a dark green and reaching 2 to 7 inches in length. Clusters of inconspicuous star-shaped flowers cover the tree in spring, transforming into small, dark-purple fruits. Although the inedible fruit smells of cinnamon, the spice is actually made from the tree’s thin inner bark. Thriving in USDA zones 9 through 11, Ceylon cinnamon handles mild frosts down to 32 degrees F but needs protection from harder frosts. It grows best in well-drained, acidic soil when it receives full sun to partial shade. Grown in a 12- to 14-inch container, Ceylon cinnamon trees can be pruned to maintain a maximum height of 3 to 8 feet.
True Cinnamon Tree
Commonly called true cinnamon, Cinnamomum verum is a stout tree with thick gray bark and low-set branches. Oval leaves emerge red, turning dark green at maturity, reaching up to 5 inches in length. Dotted with long clusters of small, yellow flowers, true cinnamon thrives in a warm, wet climate with no sustained dry season. It prefers 150 days of rain per year, or an equivalent amount of irrigation. Unlike Ceylon cinnamon, the bark of true cinnamon is typically made into oil. Growing best in USDA zones 9b through 11, it reaches a mature height of 35 to 50 feet, with 45- to 60-foot spread. Not fussy about soil, it needs full sun to partial shade.
Cinnamon or Camphor Tree
Grown in USDA zones 8a through 10, Cinnamomum camphora is commonly called cinnamon tree or camphor tree. Grown for the camphor oil distilled from its trunks and branches, it reaches a mature height of 25 to 75 feet with an 8-foot spread. Oval leaves reach 1 to 4 inches in length, emerging a dusty burgundy color. Crushed in your hand, they release the characteristic camphor smell. Tiny white flowers are followed by clusters of pea-sized fruit that turns from red to black. A drought-tolerant plant, the cinnamon tree tolerates soil pH from 4.3 to 8, prefers full sun to partial shade and survives temperatures as low as 10 degrees F. Used as lumber, the insect-repellent wood displays striking red and yellow streaks.