Wemyss came to New Zealand in 1852 on the
Agra and took up large sheep runs. Broadlands Station was a sheep station in Canterbury, located north of the
Selwyn River / Waikirikiri. It was made up of four individual runs: 40, 74, 85, and 95. After his arrival, Wemyss bought run 40, the western part Broadlands, from
John Studholme. On 5 November 1853, Wemyss bought run 95 from Studholme. Wemyss sold those two runs to
John Cracroft Wilson on 8 August 1854.
Political career Wemyss represented the Wairau electorate in the
Nelson Provincial Council from 9 October 1857 to 18 October 1859. He was appointed to the Nelson Executive Council on 11 April 1859 and remained on the executive until 6 May 1862. He then represented the Wairau Valley electorate on the
Marlborough Provincial Council from 5 September 1865 to 22 September 1869. He was a member of three executive councils of Marlborough Province: from 24 October 1865 (no end date given), from 29 May 1867 to October 1867, and from 6 July 1870 to 11 December 1871.
Fedor Kelling, who had previously represented the electorate, intended to contest the
1861 election for the
Suburbs of Nelson electorate. At a meeting with electors in
Stoke, it was decided that there is no real difference in political opinion between Kelling and Wemyss, the other contender for the position. Kelling thus stepped back from the contest. Wemyss, who was away from the district for the month during the election campaign, had placed a long advertisement in
The Colonist outlining his political opinion. This was published on 22 January 1861. The nomination meeting for the election was held at the school house in Stoke on Monday, 28 January 1861. Wemyss was the only candidate proposed and was thus declared elected unopposed. The meeting was poorly attended, with "few more there than his proposer and seconder". Before the first session of the 3rd Parliament began (on 3 June 1861), Wemyss resigned on 21 May 1861 as he had to leave New Zealand temporarily and was likely to miss the whole session, but he did not want to leave the electorate unrepresented. ==Later New Zealand career==