Bonnington, which uses the Kingfisher brand name for garden watering products, said it was losing a substantial amount in sales through companies hijacking its Amazon and Ebay listings.
Managing director of the £30m turnover company Paul Kavanagh used lawyers Pannone Corporate to end the damage to sales and brand with a five-step strategy.
This was to choose targets to go after, gather evidence, send a cease and desist letter, then tell customers and press about results.
AMA director Andrew Hartley said the market is split catalogue/mail order/internet 15 per cent, builders merchant/direct 21 per cent, DIY 31 per cent, garden centre 23 per cent and High St/supermarket 10 per cent.
He said GCA figures showed within product split catering was 17 per cent, horticulture 21, furniture 7, hard landscaping 3, sundries 15 and other 37 - showing garden centres "are no longer truly garden centres-it's a misnomer".
Hartley said DIY product split was chemicals 14, sundries 25, horticulture 13, garden buildings 6, garden leisure 18, garden equipment 24.
He said garden online spend was now £400m+, up from £100m in 2008 and rising to £700m in 2018.
Internet product mix is leisure 31, equipment 22, chems 2, sundries 13, horticulture 22, buildings 10.
Wholesaler Stax managing director David Hibbert said the company would turnover £25m in gardening sales in the years August 2015-August 2016, up from £14m in the year to August 2013. Gardening is now a quarter of turnover.
Hibbert said share had come from Solus, which has closed and that delivered business was growing much faster than cash and carry at Stax's six depots.
He said using new technology had kept Stax ahead. Turnover is now £110m, with £20m stockholding, 45,000 products, 1,000 brands, 50,000 accounts and 500 staff.