Glyphosate kills both annual and perennial weeds, but you will need to reapply every four months to a year, to keep on top of weed growth. This ready-to-use selective weed killer will take down the common broad-leaved grass invaders, but leave the actual grass alone to do its thing. We found it to be especially effective on moss and it brought worn patches in the lawn back to life as well, though it took a few applications and a couple of months. The weed killer comes as a concentrate which you dilute down and can then spray/water onto your weeds. The Resolva 5 Litre 24H Ready to Use Power Pump Weedkiller works as it should and is especially effective on dandelions.

You could sharpen your hoe and tackle the blighters before they get too comfortable or, of course, you could take a live and let-live approach, leaving the dandelions and creeping buttercup to nurture the bees.Yellowing of leaves and stems may appear within 48 hours after application though that is only the initial sign of the effect.

However, it's important to note that the World Health Organisation (WHO) considers glyphosate to be 'probably carcinogenic' to humans, and that glyphosate is the subject of several international court cases relating to cancer in humans. Selective weedkillers destroy weeds without causing harm to nearby grass and are often used on lawns, whilst the non-selective ones kill everything in their vicinity so care should be taken not to get any spray on plants, this is one of the reasons why you should not spray in windy conditions.

Our top pick for an eco weed killer, as it’s visibly effective on such a wide range of space invaders, including stinging nettles, dandelion, thistle, chickweed, horsetail, ground elder and grasses. Some species are poisonous and others cause skin irritation to humans and animals in case of contact. The before-and-after photos below highlight the change over a week, but the initial progress was apparent within hours.