C-4 is well balanced Hybrid is the result of crossing a Frostbite male with a female Shiskaberry. There are some versions of C-4 that are Cotton Candy X Shiskaberry. Either way, you’re getting a wonderful medicinal strain that is relatively easy to grow. C-4 is a quick finisher (7-8 weeks) and is naturally resistant to pests, mold, and fungus. C-4 is also a high yielder and produces abundant resin which is perfect for making hash. C-4 may be the perfect strain for patients growing their meds for the first time. C-4 medicinal qualities have been used by patients to treat depression, arthritis, anxiety, pain, and migraines. THC levels have been reportedly as high as 22%! Growing C-4 Marijuana Has Medical Benefits.