Does bleach really kill weeds?
Short answer..... YES, it will kill weeds.
Before you go all gung ho and start spraying those pesky weeds with bleach please read the rest of this article.
In addition to being an excellent spot cleaner. Bleach is also a useful and deadly weed killer.
Be warned, it was not designed to be used as a herbicide and it isn't as good as a long lasting or extra strong weed killer.
Is it safe to use bleach as a weed killer?
Short answer.... NO.
There are much more effective and safer alternatives.
Bleach is a hazardous chemical, it will affect your soil health and leave harmful residues wherever it is sprayed. It may also stain or clean your concrete / slabs etc.
It may also seep into ground water, try vinegar instead. If you don't intend to plant in the area or it's a hard surface such as a weed infested driveway then look into long lasting weed killers.
It can also be harmful to those critters living in your soil in addition to your local wildlife and of course your pets.
Please note, the use of bleach as a herbicide may be illegal where you live. Please check with your local authority.
How does it work?
The same things that make bleach a terrific spot cleaner and disinfectant also enable it to be an efficient herbicide.
Bleach is poisonous to humans, the same applies to plants and other animals. It soaks into the roots of the plant destroying them as it would any other living organism.
After bleach has been poured on an area, the soil pH becomes very high, and nothing will grow there for quite some time (often several months).
Find out how long bleach takes to kill weeds - click here.
How to use bleach as a herbicide:
If you really must use bleach as a weed killer then please follow the instructions below:
- Wear safety gloves & eye protection at all times.
- Use on a calm day to prevent accidental spraying.
- Wait a few days before pulling out the dead weeds.
- Try a little to test the effectiveness.
- Exclude children and pets from the area.
- Use too much.
- Allow kids or pets near till it's dry.
- Spray near plants you wish to keep.
- Use on/near lawns or edibles crops.
- Use near sources of water.
- Use in aquatic environments.
- Use on a day forecast for rain.
- Mix with other chemicals
Bleach can either be diluted and used in a spray bottle or used undiluted and smothered in between the cracks of paving, slabs or other hard surfaces.
Apply on a warm, calm day with no forecast for rain.
If it rains the bleach may seep into other plants or areas of your garden killing everything.
Wind may blow the bleach onto other plants or persons when spraying.
How effective is it?
Bleach will kill most small weeds, it does take time and I cannot stress this enough - it is not as effective as a commercial weed killer.
Bleach will not work against larger or invasive weeds like Ivy, Brambles or Knotweed.
Please be careful when using bleach, it can stain paving, harm soil health, insects and it is very harmful to aquatic creatures - never use bleach near sources of water.
We tried bleach as a weed killer, the first picture below was before applying bleach, the 2nd is 1 week later - you can see the weeds are starting to die but it's not as effective as weed killer
Do you recommend it's use?
Most, including us recommend against it's use.
Over using bleach can kill grass, moss, plants, trees and harm insects and animal life. It can also seep in to the ground water and have other serious environmental effects.
It may also be illegal where you live.
If you really must use it restrict usage to the cracks in your paving and use sparingly.
It would be a smarter, safer & more effective choice to use one of the alternatives listed below.
What are the alternatives?
Bleach is a harmful chemical.
Used sparingly it is an effective weed killer but there are many safer and more effective choices:
If you don't mind using chemicals to kill weeds then your best choice is probably a commercial weed killer.
They are designed to be used as herbicides and as long as you read the label and follow the instructions they are a more effective and safer choice.
I have a bad problem with weeds coming through the cracks of my travertine pavers. If i use a weed whacker to cut the weeds flush to the paver and then spray bleach will that work and keep the weeds down a while for at least 2months due to the fact I am not always at my Florida home I go back and forth about every 6 to 7 weeks.
Should work but check on a small area first, don’t want to damage your pavers
I used concentrated bleach, that is, the one which is used for disinfecting swimming pools („liquid chlorine“, which in fact is sidupium hypochlorite solution) to clean off the black algae and moss from my roof tiles, and it worked amazingly well. That is what professional cleaning services use for that purpose as well. Some of the bleach got onto a small section of my grass, which was full of weeds anyway. Of course it killed off both the grass and the weeds that it came into contact with, but my wife then put fresh grass seed onto that area, and it grew immediately, and is now the part of my lawn with the most grass, and the least amount of weeds..