Do you have trouble with weeds coming up in your gravel driveway in the middle where your vehicles tires never touch, or NOT in the country but live in the city with interlock walkways etc., are you afraid of using chemicals, then just mix 1/2 and 1/2 equal parts of vinegar with water and soak these weeds popping up, saturate the area where the roots will be affected and do this on a day when there is no rain in sight, the weeds will turn brown and dry out, and if the vinegar mixture has saturated the ground it will kill of the roots allowing no re-growth.