He is UNC's fourth commitment in the 2012 class.
"Basically, it was like the perfect fit," Johnson told The Times & Democrat. "They've got great coaching. It's a great school with great academics. It's a great environment all around. All of the rest of the schools were great, but they just stood out to me."
UNC watched Johnson throughout July -- at the LeBron James Skills Academy, Nike Peach Jam, AAU Super Showcase and at the Big Shots event in Rock Hill (S.C.) during the last few days of the evaluation period.
Johnson, who measured at the Nike Skills Academy at 6-9.5, 185 pounds with a 6-11 wingspan, entered July ranked No. 81 overall in the 2012 class by Scout.com. But his stock climbed from his performances - most notably at the Peach Jam - and he emerged from the summer ranked the No. 9 power forward and the No. 46 prospect overall.
Roy Williams extended an offer to Johnson on Aug. 2, after which Johnson unofficially visited UNC on Aug. 20 and then took his official visit to Chapel Hill on the weekend of Sept. 17. Roy Williams conducted an in-home visit with Johnson on the first day of the Fall Contact Period (Sept. 9).
Johnson also took official visits to Florida and NC State, and also considered Clemson, UConn, Louisville Ohio State and South Carolina.
Johnson averaged 23 points, 12 rebounds and seven blocks per game as a junior at Edisto and was named the Gatorade South Carolina Player of the Year. He averaged 18 points, 15 rebounds and six blocks as a sophomore. Johnson also is the 2011 South Carolina state champion in the high jump.
"Johnson is a guy that can affect the game on the defensive end. He's long, athletic and has a knack for blocking shots. The Peach Jam was his coming out party and he did it in a big way. The college coaches took notice and he was among the top standouts of the evaluation period." -- Evan Daniels, Scout.com
"He used his length and athleticism to impact things on defense, and also rebounding. Then he used his soft touch to score around the rim and from the mid-range on offense. Johnson runs the floor extremely well, and overall just was very productive. Once he gets stronger, Johnson could turn into one of the better long term prospects coming out of this class. He was very impressive for the CP3 All-Stars during the (Peach Jam). He is long, athletic, and has a very nice touch in the mid-range. Also he blocks shots, and runs the floor very well. Now he does have to get stronger, but nearly every time out he was a force, and really put up big numbers." -- Brian Snow, Scout.com