Roundup Optima+ Weed killer is ideal for really large areas, 540 ml covers up to 810 m2. This concentrate multi-purpose weed killer is for use on unwanted vegetation. Absorbed by the leaves, it moves throughout the entire plant, above and below ground. Destroys annual and deep rooted perennial weeds such as grasses, dandelions, docks, bindweed and thistles. It is inactivated immediately on contact with soil and is then broken down by soil micro-organisms to allow replanting.