The pellets, which feature the natural active ingredient Iron (lll) phosphate, were made available in a larger 1kg box as an additional option to the 800g bottle and 450g box.
Sales director Jude Beharell said: "We are extremely pleased with the performance of Sluggo in the past year. Our new packaging size has, just like the entire range, proven to be a top seller. The handy shaker box is made of environmentally friendly, recyclable cardboard and is moisture resistant. It is easy to use and protects the product from caking.
"With changing attitudes to harsh chemicals and more awareness of the ingredients used in the pest control products, I am confident that we can match or indeed exceed the 2016 success of Sluggo this year."
Sluggo Slug & Snail Killer is certified for organic use by the Organic Farmers & Growers Association. After consuming the rain resistant pellets, slugs and snails burrow into the soil to die. With Sluggo, neither dead slugs nor slime trails are visible. Any leftover pellets convert into iron and phosphate in the soil, delivering added nutrients to the plants.
Edible plants can be harvested immediately after application and children and pets do not need to be excluded from areas being treated.
The RHS said slugs and snails were the number one pest in 2016.