If you use a product like Round Up, you'll be able to read on the label that the product is a contact vegetation killer that translocates to the roots of the weeds but does not travel in the soil. It biodegrades in the presence of sunlight and fresh air and if applied according to label directions will not move into the soil and bother the lawn. An alternative is to pour boiling water on the weeds in the cracks of the sidewalk. The water will kill the weeds on contact. Hope this information helps! |