The drug cannabis or Indian hemp (Cannabis sativa), consists of the dried flowering tops of the female plants. It grows well over a considerable portion of the United States, but the production of the active principle of this plant is believed to be favored by a warm climate. For drug purposes, therefore, this crop appears to be adapted to the Southern rather than to the Northern States.

Cannabis is propagated from seeds, which should be planted in the spring as soon as conditions are suitable, in well-prepared sandy of clayey loam at a depth of about an inch in rows 5 or 6 feet apart. The seeds may be dropped every two or three inches in the row or planted in hills about a foot apart in the row, 6 to 10 seeds being dropped into each hill. Two or three pounds of seed per acre should give a good stand. About half the seeds will produce male plants, which must be removed before their flowers mature; otherwise, the female plants will set seed, thereby diminishing their value as a drug. The male plants can be recognized with certainty only by the presence of stamens in their flowers.

Ordinary stable or barnyard manure plowed in deeply is better for use as a fertilizer than commercial preparations and may be safely applied at the rate of 20 tons per acre. However, good results may be obtained with commercial fertilizers, such as are used for truck crops and potatoes, when cultivated in between the rows at the rate of 500 or 600 pounds per acre.

When the female plants reach maturity, a sticky resin forms on the heavy, compact flower clusters, and harvesting may then be begun. The tops of the plants comprising the flower clusters are cut and carefully dried in the shade to preserve the green color as far as possible. Drying can best be done, especially in damp weather, by the use of artificial heat, not to exceed 140° F.

For several years cannabis of standard (U. S. P.) quality has been grown on a commercial scale in this country, chiefly in South Carolina and Virginia. After the flowering tops are harvested they are thoroughly dried under cover, then worked over by hand, and all the stems and large foliage leaves removed. This process gives a drug of high quality but greatly reduces the net or marketable yield per acre, which usually ranges from 350 to 400 pounds. Some growers do not remove the stems and leaves, thus increasing the acreage yield but reducing the market value of their product. The quality of cannabis can be determined only by special laboratory tests, which most dealers are not equipped to make; consequently, they are usually unwilling to pay growers as high prices as they would if the low-grade cannabis were kept off the market.

The market price in June, 1920, for tested (U. S. P.) domestic cannabis was 30 to 35 cents; for nontested, 20 to 25 cents a pound.