Rock salt and table salt are basically the same thing: sodium chloride. But rock salt is unrefined and also in bigger chunks, while table salt is ground smaller. Rock salt is frequently less expensive and may be employed to cover a bigger area if you need it to destroy plants. It can change the salinity of the soil for years, so use it on your yard with care.
Concentration in Water
It doesn’t require much rock salt to effectively kill plants in your yard. Mix 1 cup of rock salt with 2 cups of water. Add it to spray bottle or pour it straight above the plants that you want to kill. Using boiling water helps dissolve the rock salt and destroy the plants boiling water hurts their leaves like it will your skin.
Just a few grains of rock salt are sufficient to kill plants. Sprinkle the salt across the base of the plant and allow it to naturally break down at the soil’s moisture. For small weeds, like dandelions, you might only need four or three chunks. For larger plants, try out a few of this salt. It works relatively fast, so if you don’t observe the plants wilting in around 2 days, add a little more rock salt about the plants’ bases. Watering the plants shortly after adding the rock salt will allow it to dissolve into the dirt.
A major problem with using rock salt even in small concentrations is that is tends to remain in the dirt for years until water leaches it outside. The salt increases soil salinity, which dehydrates the roots of plants and keeps them in absorbing nutrients that are necessary. If you include too much rock salt and it starts to change plants that you want to remain, in addition to ones that you wish to kill, start watering the plants deeply every day to try to flush the salt out of the dirt. You may not have the ability to conserve those plants, because it could take weeks of daily watering to return the ground into a feasible salinity, but it is possible to restore the dirt so that new plants may grow.
Where to Use It
Salt doesn’t always stay where it’s set — it may be washed off into your flower bed or lawn, killing large swaths of plants that you want to keep. Some salt-tolerant plants like the bigleaf hydrangea (Hydrangea macrophylla) can endure a bit of runoff, but not a complete concentration of rock salt applied nearby. Apply the salt on a day with no chance of rain to allow it to soak in where you want it without the prospect of runoff. The best places to use rock salt are those in which you don’t ever need plants to grow, like cracks in your driveway or along fence lines.