G-13 is the codename for a strain of marijuana, supposedly a mutant variety cultivated by the American government during the 1960s. According to urban legend, the CIA, FBI, and other agencies procured the best strains of marijuana from breeders all over the world. At a secret installation in Mississippi, they bred many new hybrids. Putting these together, they created a strain that was more powerfully intoxicating than any of the original hybrids. This strain, G-13, was a primarily indica phenotype strain and provided a very potent smoke and a completely mellow high. Allegedly a single cutting of this potent strain was stolen by an employee at this government facility and released into the public domain.
G-13 is no longer available in seed form, the only pure G-13 available world wide (without hybridization) are clones from mother plants. One must know a grower in order to get pure G-13. G-13 is more commonly available in Canada than anywhere else.
However the Pukka Seed Company are suppying seeds under the G13 name.
Other rumors say G-13 was developed by the University of Washington's cannabis testing facility for medical testing during the 1970s, but this, too, has not been verified.
In the early 90's characteristics of a mature, flowering G-13 plant include the top 2/3 of the plant being mostly white and unusually thicker than other sinsemilla plants. In the early 90's the name G-13 was said to have come from the number of generations it took to produce an almost perfect plant. Generation 13 was the generation in which few imperfections existed in the plant and THC content had reached a peak. Further generations were no longer needed since THC content was at its best for a sinsemilla plant.
The name G-13 is said to derive from the term Government Marijuana, the 13 used as M is the thirteenth letter of the alphabet.
Apocryphally, G-13 contains 28% THC by weight, about double the average percentage in most high-grade sinsemilla grown commercially. It has been claimed that some strains of marijuana grown in Amsterdam have met or surpassed this percentage, but accurate, verified results have not been produced. Some seed banks describe this strain as the highest THC content ever.