She joined Florida State University in 2002 and, representing the FSU Seminoles, she won NCAA All-American honours indoors and out that year. She also broke the Atlantic Coast Conference (ACC) pole vault records at the indoor and outdoor championships. Janson repeated the ACC double in 2003 and took her first major college title at the NCAA Women’s Indoor Track and Field Championship. She gained two further NCAA All-American honours in 2004 and 2005. In her final year at FSU she was the runner-up at the NCAA Indoor meet and became the 2006 ACC Outdoor champion with a personal record vault of 4.58 meters. She won the NCAA Outdoor title later that season, defeating Chelsea Johnson on countback.