UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 372 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. 
May 16, 1916 
COMMERCIAL PRODUCTION OF THYMOL FROM 
HORSEMINT (MONARDA PUNCTATA). 
By S. C. Hood, 
Scientific Assistant, Drug-Plant and Poisonous-Plant Investigations. 
CONTENTS. 
Page. 
Introduction 1 
Cultural methods for horsemint 3 
Planting the seed 3 
Soils 3 
Cultivation and fertilizers 4 
Harvesting 5 
Distillation 6 
Extraction of the thymol 8 
Yield per acre 10 
Commercial prospects 10 
INTRODUCTION. 
It has long been known that thymol is present in considerable 
quantity in the oil distilled from horsemint (Monarda punctata), 
but so far as the writer had been able to learn no attempt has been 
made to cultivate this plant for the commercial production of thymol. 
In 1907 horsemint was observed to occur in abundance as a common 
weed on the sandy lands of central Florida, and the preliminary 
examinations of the oil from the wild plants which were made at 
that time seemed to indicate that a promising commercial source of 
thymol could be developed by bringing this plant under cultivation 
and selecting for propagation types of plants best suited for oil pro- 
duction. 
The leaf area of the wild plants is rather small, and the herb when 
harvested consists mainly of woody stems which yield little or no 
oil. The fresh entire herb gathered in Putnam and Volusia Counties, 
Fla., yielded from 0.12 to 0.20 per cent of oil, although in some 
samples the yield fell far below these figures, owing to the excessive 
proportion of stems. The content of total phenols in these oils 
ranged from 56 to 62 per cent, and it was found that the phenols 
consisted almost entirely of thymol. 
38116°— Bull. 372—16 
