Swenson earned his Phi Beta Kappa Key at Rutgers University, where he received a BA degree in Journalism.
He served as an Intelligence Officer, holding the rank of captain, during active duty with the 525th MI Group and with the XVIII Airborne Corps during the 1950s.
After leaving the military, Swenson became a writer in New York City, working as a copywriter and an account executive[6] for the advertising agencies Albert Sidney Noble and Dancer-Fitzgerald-Sample.
Swenson formed his own Public Relations Agency in NYC in the 1960s, serving clients including American Cyanamid, Topper Toys, Eastern Airlines, and Shell Chemical.
During this time, and for more than 25 years, Swenson wrote a gardening column for NEA-United Media which appeared in more than 200 papers nationwide.
Among the authors of the eighty books he published during his ten-year tenure as Editor-in-Chief were Bill Caldwell and Marjorie Standish.
Swenson and his wife Sheila raised four boys: Peter, Drew, Boyd and Meade who all live nearby in Maine with their families.