The group, which also has two nurseries, saw turnover rise to £19.72m from £17.30m from 29 December 2014 to 3 January 2016, according to newly published figures.
Operating profit rose from £1.47m to £2.17m.
The group, owned by the White family, says it grows 80 per cent of tis own plants at its main Ottery St Mary garden centre and nursery and at the Lymington, Hampshire garden centre and nursery. Otter also has garden centres at Plymouth, Torbay and Wincanton.
Woodthorpe Hall Garden Centres (Great British Garden Centres) has increased turnover from £23.08m to £24.35m in the year to 31 December 2015. Profit after tax rose from £1.34m to £1.67m. Gross margin rose from 25.87 per cent to 27.22 per cent. Directors expect similar similar strong sales and profitability for 2016 results. They have achieved their aim of owning 10 centres.
Westcountry Garden Centres (Carnon Downs and West Buckland) has turned over £4.27m in the same period, according to new results, up from £4.04m, with pre-tax profit of £887,000 from £507,000.