Genetics: Critical Jack is a fierce combination of Critical Mass and Jack Herer. Flavor & Aroma: Critical Jack has a natural earthy essence with hints of pine, pepper, and fruit. Effects: This hybrid means business. It has happiness and euphoria written all over it and is heavy enough to relax you without tranquilizing you. Medicinal Uses: Critical Jack is a great choice for stress, depression, and lack of appetite. Potency: Critical Jack has a measured THC content of 21%. Grow Info: The grow time is 10 weeks and bears heavy plants.