Unwanted plants leach nutrients and moisture from the soil, depriving other plants and detracting from the attractiveness of a garden. You can remove weeds from driveways and paths by using salt and vinegar, which act in different ways to kill plants. It is not recommended to mix the two together into a single solution. Use salt and vinegar separately in a two-pronged approach for difficult-to-kill plants, while controlling damage to the soil and desirable plants.
Cover plants you wish to keep with a moisture-proof plastic tarp or rubbish bag. Cover the ground around the plant with plastic so the vinegar does not contaminate it and kill beneficial micro-organisms.
Spray full strength white or cider vinegar liberally with a spray bottle onto the plant you wish to kill. Vinegar is a desiccant, leaching water from the plant and causing the top part of the plant to die. Not all plants are vulnerable to vinegar and may require several applications. The roots may not die, depending on the type of plant and how far along it is in its growth. Young plants die more quickly than mature plants.
Cover the treated plant with a moisture-proof plastic tarp and do not water the area around it for two to three days until it is evident the plant is dead.
Spot-treat weeds in driveways, patios and paths by spraying vinegar full strength onto the weeds. Take care that excess vinegar does not drain onto grass or into gardens.
Treat plants only located in an area without vegetation you want to keep. Salt is a desiccant but stays in the soil for a long time, not allowing other vegetation to grow.
Treat a plant you wish to kill by digging a small hole around its base. Use a salt shaker to sprinkle salt sparingly into the hole for a small plant, using more salt for larger plants. This process may require several applications as you determine how much salt is necessary to kill the plant without doing damage to the soil around it.
Fill the hole with dirt to cover the salt. A small amount of salt will dissipate after several rainfalls. Large amounts of salt can damage the soil for months or even years.
Start by using vinegar and salt in areas where damage is not likely to spread. This way you can gain experience in how much to apply to achieve your desired results.
Salt acts best to kill the plant root when sprinkled directly onto and around the base of the plant, while vinegar is a defoliant that kills the top of the plant. Mixing salt and vinegar into a solution may be appropriate for car parks or gravel driveways, but the combination of the two is difficult to control during application and can damage surrounding plants and soil.