Also known as King Louis, the strain is named for its royal caliber of THC, reportedly 20-to-28 percent based on weight. Growers report the strain comes from a rare cut of the Los Angeles-based OG Kush that was specially bred for higher potency. The cultivar features unmistakable OG characteristics — a powerful diesel and skunk aroma, and sticky buds littered with trichomes. The strain thrives in both indoor and outdoor gardens, flowering in 60 days, or in late September, respectively. Novice growers may find Louis XIII difficult to handle, as it requires drier climates and plenty of attention to produce larger yields.