AmazingĀ  Cultivation

Hemp being harvested
Climate zones well suited for the cultivation of hemp

Millennia of selective breeding have resulted in varieties that look quite different. Also, breeding since circa 1930 has focused quite specifically on producing strains which would perform very poorly as sources of drug material. Hemp grown for fibre is planted closely, resulting in tall, slender plants with long fibers. Ideally, according to Britain's Department for Environment, Food and Rural Affairs, the herb should be harvested before it flowers. This early cropping is done because fibre quality declines if flowering is allowed and, incidentally, this cropping also pre-empts the herb's maturity as a potential source of drug material. However, in these strains of industrial hemp the tetrahydrocannabinol (THC) content would have been very low regardless.

The name Cannabis is the genus and was the name favored by the 19th century medical practitioners who helped to introduce the herb's drug potential to modern English-speaking consciousness. Cannabis for non-drug purposes (especially ropes and textiles) was then already well known as hemp.

The name "marijuana" is Spanish in origin and associated almost exclusively with the herb's drug potential.