Salt is destructive enough to plants that it has been used as a historical war tactic in order to kill the crops of enemies. The deicing salt that makes roads less slippery can also have a detrimental effect on plants when the salt gets intermingled with the soil. Fortunately, salt can also be used for good. If used properly, homeowners can use salt to kill weeds and grass.
Salt Application
While salt is effective at killing grass and weeds, it can seep into the soil and remain there for a long period of time. As a result, the soil can become difficult to grow other plants in. Gardeners who do not plan on using the plot of land to grow new plants might not mind this result. However, gardeners who want to use the soil at a later date might want to use a small pinch of salt, which is placed at the base of the plant. This salt will be enough to harm the plant but will dilute over time as it rains, leaving the soil suitable for future growth.
Water Solution
Salt can be put in a water solution, which can be added to a syringe and injected into the plant. Eight to 10 g of salt should be added per liter of water. However, the saltwater can also simply be sprayed on to the soil, as long as no future plants will be grown in the area. In water form, the sodium and chloride ions break apart and the chloride can easily be absorbed by the plants to the extent that they become toxic, according to the University of Vermont.
Vinegar Solution
Salt can be combined with vinegar to create a solution that will kill weeds and grass, according to GH Organics. Add 1 1/4 cup of salt to every gallon of vinegar. The effectiveness of this approach is maximized if the area is not watered for 24 hours on a hot day. Salt has the ability to absorb moisture and can cause the plants to thoroughly dehydrate. However, very cold days also work, since plants that are full of sodium lose their ability to resist cold, according to the University of Vermont.
Warning
Salt is capable of corroding some structures such as concrete and should not be used near them unless techniques are used to minimize the amount of salt that is used.
Removing Salt From Soil
When soil becomes too salty as a result of saltwater treatments, the salinity of the soil can be lowered by soaking the soil very thoroughly with water. Over time, the water will carry salt deeper into the ground away from the plants, according to Colorado State University. Burying a drainpipe in the soil to drain water out more quickly can be used if the water table is too low for the salt to be leeched far away from the plants. However, given the labor intensiveness of this project, the draining method is only used in cases where a lot of the land is salty.
