William Barbour Wilson was born, on 2 April 1819, at Castle Douglas, Kirkcudbrightshire, Scotland, the eldest child of Jane Thomson and her husband, William Wilson. William Barbour Wilson was apprenticed as a nurseryman in Scotland, and became an overseer on estates in Ireland. He arrived in New Zealand on the Mariner on 6 August 1850, and travelled to Nelson, Wellington and Auckland, arriving in Canterbury in late July 1851. He married Elizabeth Williams, at Christchurch, on 19 November 1856; they had 13 children.
Wilson's first nursery, from 1851 to 1856, was adjacent to the The Bricks wharf on the River Avon. His Christchurch Nursery (approximately 18 acres at maximum in 1857) straddled the south-east entry to the city, along Ferry Road and High Street. His nursery stock was selected primarily for timber, shelter, and hedging purposes, and Wilson did much to encourage planting for shelter. He played a major role in initiating effective methods for importing tree seed in a viable state, and was also significant in the introduction into Canterbury of conifers, which dominated his stock from the 1860s onwards. Despite extensive competition Wilson remained the dominant Canterbury nurseryman until 1873. His writings on horticulture were limited, but his 'Garden calendar' appeared for many years in the Southern Provinces Almanac. It was published as a pamphlet, New Zealand garden calendar, in 1878, together with his 1864 article on 'The introduction of trees, flowers, and fruits into Canterbury'. His business catalogues were among the first issued in New Zealand.
Wilson's landholdings were considerable: in 1882 he held over 1,700 acres in country lands, and property in Christchurch valued at over £45,000. His Cashel Street nursery site had already been sold in 1877 for £24,557. Wilson frequently used land for nursery purposes until it became too valuable for further use; it was then subdivided or leased. Other business ventures included a general trading company; a real estate and auctioneering business; a controlling interest in the Halswell quarries; and a half partnership in the trading vessel Rifleman.
Wilson was very active in political and public life. He was elected to the provincial council in 1864 and 1866, serving until 1870, and to the city council in 1867, becoming chairman in that year. In 1867, when Christchurch came under the Municipal Corporations Act 1867, he was elected as the first mayor. Wilson was the chairman of municipal subcommittees responsible for the first landscaping of the River Avon in 1862, and the redesign in 1867 of the earlier, abortive designs for tree planting in Fitzgerald and Bealey avenues in 1867. He was president of the Christchurch Horticultural Society (1866–70 and 1874–76). In 1876 Wilson was accused of fraud in the handling of a trusteeship, and he lost the case on all counts. This appears to have brought about the end of his public life.
Physically Wilson was large and dominating, 6 feet in height and 17 to 18 stone in weight. He was known as 'Cabbage' Wilson. His ability with words made him both a person to be feared and a figure of fun. In political debate his repartee often won the day, although his verbal excesses sometimes became a subject of ridicule. He died in Christchurch on 8 November 1897.