John Denniston Heron born 1824 Minnigaffe, Scotland

I am trying to find out what happened to John Denniston Heron. I have found him on the 1851 census, he was an under gardener at Whitworth Hall, in Whitworth, Durham,England, and then I have found a marriage for him in Stella, Durham,England, to a Margaret Thompson in 1853.His occupation is a gardener. I have tried to find him after this on the English census but with no luck. He had a sister who emigrated to NewZealand, and some of his mothers family were in Canada. Has anyone on the list come across him. On the census and his marriage certificate he had changed his age so I am looking for him being born from around 1821-1826.
I am hoping that someone may have come across him in their research.
Susan