The best weed killer will show visible results within 1 – 2 days. My advice is to look for a large capacity that will treat a surface area of at least 100 m² as these will generally offer the best value for money. Prioritise weed killers that kill the entire plant, including the roots, to prevent the weed from re-sprouting . Systemic weed killers are slower to work than others but can kill even the most resistant plants like brambles and briars. Note that systemic weed killers are sometimes called industrial weed killers. Post-emergence weed killers are designed to be applied to the weed after sprouting, while pre-emergence weed killers (also known as residual) are applied to soil before growth begins.

One downside of this weed killer is that it makes the soil unusable for a period of time. This is fairly disappointing if you’re wanting to get planting. The instructions state that it takes a ‘growing season’ to wear off, meaning potentially an entire spring or summer!Speed of Results: Ideally, we were looking for fast-acting products that showed results within 24 hours. Any product that achieved this was rated higher. If the product also killed the roots within a 2-week window, this was also deemed highly effective. We marked down any weed killers that took 7 days to show the first signs of success, and those that took even longer received the lowest rating. Other (residual) weed killers are applied to the soil which then prevent species of weeds from germinating and ever appearing.

Forks, trowels and hoes are good to have in the armoury against stubborn weeds. But sometimes you need something more. An effective weed killer can help truly eliminate weeds, keeping your garden looking pristine. Plus, they’re not only useful in the battle against common weeds; certain weed killers can get rid of brambles, nettles and thistles as well. This easy mix liquid concentrate formulation is approved for use all around the garden, on gravel areas, paths, drives and along fences. It can be used to clean up weedy areas before planting vegetables, flowers, shrubs and to renovate overgrown areas. Apply using a garden sprayer. Rotate nozzle to ‘spray’ or ‘stream’, hold sprayer approx 50cm from the target weed to lightly wet the leaves and avoid run-off. It leaves no harmful residue and it’s very easy to deploy. It should kill the weeds in your garden and their roots, before degrading in the soil without leaving any damaging substances in its wake. Its real strength, though, is that it can control weeds that other weed killers tend to struggle with, including horsetail/mare’s tail and ground elder, as it did on an overgrown bank and a disused veg bed where other weed killers had failed miserably. It’s a good bet if you need a powerful weed killer but you don’t want to spray something really nasty on your plot.There are also some products on the market referred to as “natural” weed killers. Corn gluten is one ingredient which you’ll find used in some selective, pre-emergent weed killers. Corn naturally secretes a chemical that kills other nearby plants. That chemical is found in significant concentrations in corn gluten. However, it is generally not effective against common lawn grasses which is what makes it a great option for pre-emergent weed control in lawns. Flazasulfuron works on weeds when they first start growing, as well as when they are in their ‘adolescent’ stage. It’s absorbed by the roots and then works its way through the rest of the plant. This weed killer is very effective, destroying weeds at the roots within 2 weeks. The smell alone is enough to indicate that it’s exceptionally powerful, so while it is very effective, a lot of care needs to be taken during use. It worked on all the weeds I treated it with.