The latest figures from market analyst GfK show that, of the top ten weedkiller products sold in the UK, five are branded Roundup - including the top two slots.
The figures also show that the brand has grown its value share by 5.2% from 25.1% to 30.3% of the market.
Commenting on the news, Roundup lawn and garden UK business director Gary Philpotts said: "The figures speak for themselves. Consumers are choosing Roundup over the competition, a clear indicator of the brand that will give you a higher return on your investment.