Here's an article I wrote for my orchid society on Cinnamon and its anti-bacterial/anti-fungal benefits.
Cinnamon (Cinnamomum zeylanicum), one of the oldest spices known, is derived from the bark of a small Southeast Asian evergreen tree and is available as an oil, an extract, or a dried powder. It’s closely related to cassia (C. cassia) and contains many of the same components. Due to its’ demand, it became one of the first commodities traded regularly between the Near East and Europe. Ceylon cinnamon is produced in Sri Lanka, India, Madagascar, Brazil and the Caribbean, while cassia is mainly produced in China, Vietnam and Indonesia.
Cinnamon has a long history both as a spice and a medicine. It was mentioned in the Bible and was used in ancient Egypt not only as a beverage flavoring and medicine, but also as an embalming agent. Cinnamon’s unique healing abilities come from three active components found in the essential oils contained in its bark: cinnamic aldehyde, cinnamyl acetate, and cinnamyl alcohol.
One famous anecdote involving the use of cinnamon involves the story of Four Thieves in Toulouse, France in 1628-1631 who were caught and convicted of going to the houses of plague victims, strangling them in their beds and then looting their dwellings. For this they were condemned to be burned at the stake. Given the virulence and deadliness of the plague, authorities were astonished by the indifference of the thieves to the contagion. In order to have their sentence mitigated, the thieves revealed their secret preservative, a blend of herbs and essential oils including cinnamon and cloves. After this, sponges soaked in cinnamon and cloves were placed in the rooms of the ill and infirm.
Cinnamon has recently been studied for its ability to help stop the growth of bacteria as well as fungi, including the commonly problematic yeast Candida. In laboratory tests, growth of yeasts that were resistant to the commonly used anti-fungal medication fluconazole was often stopped by cinnamon extract. Researchers at the Institute of Food Technologists’ 1999 Annual Meeting presented findings that revealed cinnamon to be a lethal weapon against E. coli. In apple juice samples inoculated with about one million E. coli bacteria, about one teaspoon of cinnamon killed 99.5 percent of the bacteria in three days at room temperature. Research at the University of Illinois at Chicago’s College of Dentistry determined in 2004 that chewing a stick of gum would knock out offensive oral bacteria. Although many extracts showed promise, few proved as potent as oily cinnamic aldehyde, the principal flavor compound in cinnamon.
What does all this have to do with orchids? Cinnamon’s anti-microbial nature makes it the perfect natural preventative for common minor orchid ailments. Dust powdered cinnamon on newly cut or damaged leaf surfaces to help heal the cut. Cinnamon has been effective in arresting the development of minor cases of Erwinia (bacterial rot) in some plants. Remove any affected areas of the plant until you reach healthy green tissue, and then dust with cinnamon. However, because of its desiccating nature, using cinnamon on the roots of orchids may not be the best idea. Informal experiments involving the use of cinnamon on healthy root tips have resulted in the roots drying out and shrinking excessively.
Regarding Hydrogen Peroxide - a person in my society swears on a tablespoon per gallon in his watering regimen. We've had numerous discussions about what this would do (other than turn to water) but I often do it because he swears by it (it's Bob Richter if anyone's wondering) and his plants look pretty good.
