As deputy-orator to the university, some time previous to 1620, he delivered an "eloquent oration" upon James I's gift of his own works to the library.
James I, according to Wood, gave to Gardiner the reversion of the next vacant canonry at Christ Church in reward for a speech made before the king "in the Scottish tone".
He continued deputy-orator, and in this capacity made the university oration to the king on his return from Edgehill.
He lived obscurely at Oxford, befriending poor royalists, until the Restoration, when he was reinstated (July 1660).
He died at Oxford in 1670, aged 79, and was buried in the north choir aisle of Christ Church Cathedral, where a monument to his memory was erected, bearing a laudatory inscription by South, who succeeded him in his prebend.