Captain Ponsford joined the Canadian Penitentiary Service as Warden of Manitoba Penitentiary, Stony Mountain, on March 4, 1913. On April 1, 1914 he became Warden of the Alberta Penitentiary, in Edmonton, and closed that facility in 1920. On April 27, 1920 he was appointed Warden of Kingston Penitentiary.
During his occupation of Cedarhedge, Warden Ponsford made many changes to the building, He added the second-floor bay window on the main façade in order to see who was approaching the house from the driveway at the south-east corner of the property. There was also a lengthy debate about his wish to install bathrooms in the house. Headquarters felt the need to remind him that this was a government residence and not a "millionaire's" mansion!
The Ponsford's were quite active in the local social scene. In October of 1922 Mrs. Ponsford entertained the Anglican Girls Club of Queen's University at Cedarhedge. The Oct.25, 1922 issue of the Kingston Standard reported that "…Hallowe'en favours, yellow candles and ferns formed the decorations in the drawing room and were used in the tea room. The Dean of Ontario and the Rev. W.E. Kidd were present at the tea hour to welcome the College girls to the Anglican Club."
Warden Ponsford was on retiring leave from January until October of 1932. During his leave, the first major riot in the history of Kingston Penitentiary took place. At this point, it is not known whether Warden Ponsford continued to reside at Cedarhedge during his leave.