Successful weed destruction requires several steps. When making the financial and time investment involved with laying sod in your yard, it’s wise to eradicate weeds through at least two steps. A non-herbicide, slow removal option involves solarizing the area with black plastic and sun for at least four to six weeks, but the success rate on this process is controversial. Lifting old grass out is exhausting and dormant weed seeds always remain behind. Spraying non-selective herbicides with glyphosate kills the growing grass and weeds, speeds up the timeline and increases the success rate.
One week prior to applying the herbicide, water the area to be treated to encourage plant and weed growth. After one week, apply a second treatment of herbicide. Glyphosate is rapidly translocated through growing plants but should not be applied if rain is forecast within two days after being applied. It works fast, but may require up to seven days to be fully absorbed in the roots.
Wait three days after applying the final treatment and then remove the dead grass and weeds. Wait a total of seven to 10 days following the second treatment before laying sod. Apply a thin layer of organic compost to the soil if desired and rake the exposed soil smooth before laying your sod.
As when using any herbicide, read the label and instructions carefully. Each set of product-use instructions will differ slightly. This non-selective herbicide kills any growing vegetation with which it comes in contact. It moves through the leaves into the roots, even on woody plants. How quickly it acts depends upon the type of plants, as well as temperature. Shrubs might not show damage immediately. Don’t spray on a windy day to avoid herbicide drift, and don’t spay near water. Keep children and pets out of the area until the spray has dried.