After the war, he joined the Kansas Army National Guard in June of 1948, serving as Battery Executive Officerand later as forward observer and liaison pilot of the 127th Field Artillery Battalion. In December 1950, Gardner transferred toAir Base Flight E, Air Section, State Headquarters and Headquarters Detachment. When the Headquarters, Kansas Air National Guard was organized in 1951, Gardner became the Headquarter's first commander. After this assignment, he held a number of significant positions in the newly formed Air National Guard including the Chief of Staff, Operations Staff Officer, Administrative Staff Officer, Executive Support Officer, and Director of Personnel Management. Ultimately, he finished his career with duty as Assistant Adjutant General, Air, and Commander, Headquarters, Kansas Air National Guard.

Since he had served in both the Air and Army National Guard, Gardner had a unique career. While he was a command pilot with over 6,200 military and civilian flying hours, he also had service within a field artillery battalion giving him unique insights into both branches of the service. His devotion to both branches of the Kansas Nation Guard and his ability to relate and work with a wide range of individuals on both the State and National level, has made an important place for General Gardner in the history of the Kansas National Guard.