I have just cleared an area of my garden of all weeds and grass. Could you please advise as to what weed killer I could use to kill any roots left in the soil before I plant any shubbery?
Root/Soil Weed Killer
Most of the root killers I know of are for septic systems. Maybe someone else has an answer. Usually, plants/shrubs, etc are killed before cutting them off so the herbicide can penetrate the leaves to the roots thus killing the whole plant. Round Up is one such product. I don't use chemicals but have great success in killing off unwanted plants by cutting them off to the ground, laying down heavy layers of newspaper and then making openings where you are planting the shrubs. Water them well and then add mulch to hide the newspaper. This is great for you soil because the worms love it and kind to the environment. You can also use landscaping fabric beneath the mulch but it does not feed the soil.
Most of the root killers are intended for septic root clogs but maybe someone else has a solution for you. Normally, plants are killed PRIOR to cutting them off with a product like RoundUp. It kills the roots, too, so no further action is required. A friendly environmental answer is to put down a weed block fabric or heavy layers of newspaper and cover with mulch after you plant your shrubs. Newspapers break down and you may have to do this every couple of years to keep our weeds, grass, etc., but worms love it and it will improve your soil. You can also use plastic but it breaks down and you have tons of tiny pieces of plastic to clean up plus it does nothing to improve the soil.