Rootblast super strength tough weedkiller 250ml is a systemic herbicide thats moved from the point of application leaves stems green branches cut stumps to kill the underlying roots first signs of control a yellowing of the leaves may take from a few days to 2 3 weeks to appear simply dilute with clean water and apply where needed no long lasting activity occurs in the soil after application and the ground may be planted after the treated vegetation has died backwarningcontains 360g