Purple Kush is a pure Indica strain that resulted from crossing the Hindu Kush and Purple Afghani strains. It is one of the most potent Indica strains in the world, with an average THC level of 22%. With adjustments in the growing methods, harvesting, and curing, some growers have managed much higher THC content. Top marijuana strains with the highest yields Best outdoor strains for high yields 8. Super Skunk strain 7. Chocolope strain 6. Super Silver Haze strain 5. Amnesia Haze strain 4. Strawberry Kush strain 3. Sour Diesel strain 2. Northern Lights strain 1. Gold Leaf strain FAQS about highest-yielding strains Here are some amazing seed deals.