Two strains called Black Jack from different seed banks, one from from Nirvana Seeds in the Netherlands and the other from Sweet Seeds in Spain.
Nirvana Seeds Black Jack
The Nirvana Seeds version of Black Jack, spelled “Blackjack” by the original breeder, is a cross of Black Domina and Jock Horror. This cultivar of Blackjack tends to produce a euphoric, energetic, uplifting head high, while carrying a flavor of fresh pine tree and sweet citrus.
According to Nirvana Seeds, the strain has mostly sativa lineage, grows short and produces medium-sized yields of large, pungent, trichome-heavy buds during a 56-to-63-day flowering period. Best suited for indoor grows, Blackjack can reportedly yield between 400 to 500 grams per square meter using the Sea of Green (SoG) method.
Black Jack by Sweet Seeds
The Black Jack strain bred by Sweet Seeds is a cross of Black Domina and the iconic Jack Herer strain.
According to Sweet Seeds, the strain is a well-balanced hybrid that tends to produce powerful psychotropic effects.
This particular Black Jack cultivar is reported to grow as tall as 3 meters, or nearly 10 feet, producing enormous yields of earthy, lemony aromatic buds in a 63-day flowering period. Responsive to either indoor or outdoor grows, Black Jack produces a lot of stigma hairs and becomes extra resinous when grown in soil with ample amounts of sunlight, according to Sweet Seeds. Black Jack is the winner of 10 international cup awards worldwide, most recently winning an award at the 2017 Secret Cup Napoli in Italy and I Certamen de Horticultura Cannábica in Uruguay.