Does salt really kill weeds?
Yes, it works and works well.
When used properly, salt can and will kill your weeds.
Do I need special garden salt?
It may sound silly but we get asked this an awful lot.
No, any salt will do, even regular old table salt.
Is it safe to use salt as a weed killer?
Yes, salt is one of the safest & most natural herbicides you can use. Alongside hand weeding we recommend you try it before using any other herbicides.
The benefits of using salt as a herbicide:
- It's super cheap and readily available.
- It's natural and is unlikely to do any harm.
- Works quickly and suppresses regrowth.
- Overuse won't harm the environment.
- Can be used near edible crops.
The disadvantages of using salt as a herbicide:
How does it work?
Salt is easily dissolved in water. When applied to a weed it is quickly absorbed where it makes the plant to retain more water causing it to wilt and die.
It will take up to 10 days to be fully absorbed by the plant. Depending on weather conditions and the size of the weed.
How to use salt as a weed killer:
2 parts salt to one part water. The stronger you make it the better it will work, this is the minimum dose for effective use.
Just sprinkle it on:
No need to dilute, you can just pour it right from the container onto your weeds and the rain will do the rest.
In a spray bottle:
A small hand sprayer is useful for small areas or precision spraying in soiled areas with ornamental or edible plants.
Spray the solution onto the leaves, stem and around the roots. Take care not to use too much or it may soak into the soil and other surrounding plants.
In a pressure sprayer:
For accurate dispersal across a wide area this is the best method. Dilute as per the instructions above and spray onto the weeds leaves, stems and around the roots.
With hot water:
A large pot is best, just pour it onto your weeds, they will quickly die. Remember to be safe around scalding water.
Combine salt & vinegar for an effective weed killer. Works especially well on hard surfaces like paving & gravel.
Add a small squeeze of dish soap to the salt and water solution for a more effective weed killer.
The soap is a surfactant which will make the uptake of the salt by the plant both quicker and more efficient.
How effective is it?
Salt is highly effective against small weeds. It is much less so against deep rooted perennials and larger weeds.
Because you need a large amount of salt it's best used on a small scale. In the cracks of paving or in localized areas.
Precautions to take:
Salt is pretty safe as far as herbicides are concerned.
There is no need to use safety gear when using it on it's own.
However it can be harmful to your soil health. Apply too much salt and nothing will grow in that area for a while.
Salt and grasses don't mix, if your preparing to clear and area to plant grass then don't use salt to clear the area.
The critters living in your soil won't take to being doused in salt either. This may cause long lasting damage to your garden, be careful and remember: DON'T OVER DO IT!
What are the alternatives?
As noted above salt is an excellent herbicide for small scale weed control. If you have invasive weeds or larger deep rooted perennials it won't be effective enough to permanently kill them, only killing the bits it touches.
If you have a large area to cover or large weeds consider these alternatives before using salt: