Edward Garwood Alston, farm manager and collector of natural history specimens, was the eldest son of the land surveyor Garwood Alston* and his wife, Elizabeth de Witt. From 1884 he and his father managed an agricultural settlement at Vanwyksvlei, in the Carnarvon district. In 1885 and 1886 he presented many insects from Vanwyksvlei, with natural history notes, to the South African Museum, Cape Town. Soon afterwards he left the settlement, for he subsequently donated many insects from Parys (1888, 1889), and Klerksdorp (1890). However, by 1892 he was back in the Carnarvon district, donating insects from the farm De Naauwte. He remained in the region until at least 1900 and during this period made the following donations: Some succulents from Carnarvon to P. MacOwan* at the Cape Government Herbarium (1895), and live succulents from Namaqualand to Dr S. Schonland at the Albany Museum, Grahamstown (1899); some semi-fossilised shells from the neighbourhood of Vanwyksvlei to the Albany Museum (1897), and shells from there to the South African Museum (1898). He still resided at Vanwyksvlei in 1900. He was commemorated in the species names of the succulents Trichocaulon alstonii and Adromischus alstonii.
In 1886 P. MacOwan, the Colonial Botanist, obtained seeds of the Australian salt bush, Atriplex nummularia and A. inflata, from Australia and gave them to Edward's father, Garwood Alston, for test planting at Van Wyk's Vlei. They raised the plants successfully and in 1893 distributed seeds to farmers in many parts of South Africa. Edward described the experiment in a pamphlet titled Australian salt bush (Cape Town, 1893, 7p), published by the Department of Lands, Mines and Agriculture. In some of the saline soils of the Karoo the first-named species has spread widely and is an important fodder plant. It is popularly known as Alston's Saltbush.
In 1904 or 1905 Edward was appointed manager of the government farm Roodepoort, an agricultural settlement near present day Koppies in the Free State. He appears to have owned the farm Klipfontein, adjacent to Roodepoort, at this time, for in 1905 he offered 300 morgen of this farm for sale. He still lived at Roodepoort in 1910, but by 1917 was living at Ceres in the Cape Province.
He became a member of the South African Philosophical Society in 1897 and was still a member of its successor, the Royal Society of South Africa, in 1917. He was survived by his wife, Annie Cornelia Alston.