In 1906, Garden was a Church of Christ minister at Harcourt, Victoria. The next year on 6 May in Melbourne, with the forms of that church, he married Jeannie May Ritchie, from Leith, Scotland. By 1909 he was a member of the Labor Party and also a Baptist preacher at Maclean, New South Wales. In 1914 he was living at Paddington and working intermittently at his trade; he became the president of the Sailmakers' Union and its delegate on the Labor Council of New South Wales, which was to be his power base until 1934. In 1916 he was elected assistant secretary of the council, and in 1918 became its secretary. He failed as a Labor candidate at Parramatta in the 1917 State elections. Before that, Garden was employed from 1915 by the Department of Defence at its ordnance store at Circular Quay. In 1916 he was fined £10 for improperly accepting a gift from a supplier to the department and was dismissed on 14 March 1917 year after admitting that he had destroyed an important voucher.