Watford are currently at the top of the Championship table with 72 points from 38 matches, level on points with second-placed Middlesbrough but ahead of goal difference.
Gardner, who joined Forest on loan from Aston Villa in the January transfer window, hopes that the Hornets return to the English top flight.
Watford are on a great run of form at the moment and will be backed by many football followers to finish in the top two of the Championship at the end of the season.
Slavisa Jokanovic’s side have won their last two league matches and are unbeaten in six games.
Meanwhile, Forest are in the hunt for a place in the Championship playoffs. The Reds are currently ninth in the league table with 57 points from 38 matches, eight points behind sixth-placed Brentford.
Watford host Ipswich Town in the Championship on Saturday, while Forest take on Norwich City away from home.