The cultivation of drug plants, to be successful in this country, will probably require the introduction of improved methods and the extensive use of machinery to replace hand labor so far as possible. Growers of mints and numerous other plants yielding essential oils will find it desirable to equip themselves with a suitable distilling plant, although the latter can not be operated most economically when only a small quantity of material is available for distillation. The natural tendency will be to increase the acreage in the interest of more efficient operation, but here again there is danger of overproduction, and prospective growers should thoroughly acquaint themselves with market conditions before bringing very large areas under cultivation.
Very few, if any, drug plants are used in quantities sufficient to make them a promising crop for general cultivation. Many of the common ones, which can be grown and prepared for market with little difficulty, bring but a few cents a pound, and their cultivation offers little prospect of profit. A number of the high-priced drug plants must be given care for two or more years before a crop can be harvested, and, since expensive equipment is usually required for their successful culture, the production of such crops offers little encouragement to inexperienced growers who are looking for quick returns and large profits from a small investment. The production of drugs of high quality requires skilled management, experience in special methods of plant culture, acquaintance with trade requirements, and a knowledge of the influence of time of collection and manner of preparation on the constituents of the drug which determine its value. Small quantities of drugs produced without regard to these conditions are apt to be poor in quality and so unattractive to dealers and manufacturers that the product will not be salable at a price sufficient to make their production profitable. In general, the conditions in this country seem far more favorable to the growing of drug plants as a special industry for well-equipped cultivators than as a side crop for general farmers or those whose chief interest lies in the production of other crops.
Although a number of plants which yield products used as crude drugs are common farm weeds, they usually occur in scattered situations and in such small quantities that their collection would scarcely prove profitable for the farmer. Even when relatively abundant it is a matter for careful consideration whether the time and labor necessary for their collection might not be otherwise employed to better advantage. Moreover, it is not always easy to distinguish medicinal plants from others of similar appearance, and collectors not infrequently find that they have spent their time in gathering plants practically worthless as crude drugs. In proportion to the labor required in their collection, relatively low prices are paid for most crude drugs obtained from wild plants, and the farmer who turns to drug collecting as a source of additional revenue will probably meet with disappointment.
[THE CULTIVATION AND HANDLING OF DRUG PLANTS.]
The following cultural directions and suggestions regarding the handling of a number of drug plants have been compiled in part from the records of the Office of Drug, Poisonous, and Oil Plant Investigations and include data secured by various members of the staff of that office connected with testing gardens in several widely separated localities. The probable yields per acre are in many cases estimates calculated from smaller areas, and considerable variation from the figures given must be expected in actual practice. The prices mentioned are given merely to indicate the comparative value of the products concerned and not to fix the actual price which the grower of drug plants may expect to receive. This will depend very largely upon the state of the market at the time the crop is offered for sale.
The plants mentioned in the following pages were selected for discussion because information regarding their cultivation is in constant demand. The purpose of this bulletin is not to recommend these plants for cultivation, but to give information concerning their culture which may be helpful to persons who are considering the production of drug plants on a commercial scale.[2]
[2] For information in regard to weeds used in medicine not herein considered, see Farmers' Bulletin No. 188, which may be obtained from the Superintendent of Documents, Government Printing Office, for 5 cents.