Peppermint Oil Possibilities Grow

MADISON, WIPeppermint-oil production could move south to compensate for shrinking croplands in the northern states.

U.S. peppermint essential-oil production dropped 19.4%, from 3.1 million kg in 2007 to 2.5 million kg in 2008 due to the decline of traditional peppermint production areas in the northwestern United States, a decline caused by expanding corn acreage. Long days and cooler nights are generally believed to be a must for a good yield of peppermint (Mentha x piperita L.) with desirable oil composition The lack of research on peppermint productivity, essential oil content, and composition in the southeastern United States has prevented growth in that geographical area.

A 2-year field study in Mississippi by Zheljazkov et al. published in the January-February issue of Agronomy Journal evaluated the effect growing conditions on peppermint yields, oil content, and composition. The study found that with some changes, a successful peppermint crop can be established in the southern states. Our results suggest the first harvest in Mississippi should be delayed until the end of July to promote accumulation of the main oil ingredient, menthol, in peppermint oil, says research lead Zheljazkov. Peppermint could provide two harvests per growing season under the Mississippi climate, with oil yields and composition similar to those from other peppermint production regions.