Environmentally friendly weed exterminator

It’s that time of year when unwanted greenery pushes its way up through every available crack in our patio stones, sidewalk and even in between our retaining wall and driveway. It is of course illegal to use most chemical pesticides and herbicides in Toronto now (not that I would use them if they were still allowed), but I’ve found an all natural and very safe herbicide which we can use on the little green opportunists.

The Weeds
Weeds making homes in the patio stones

After buying a commercial brand “natural” weed killer from Home Depot a couple summers ago, and discovering that it smelled an awful lot like vinegar, it got me thinking that there must be a way to make this stuff at home for a fraction of the cost (that product cost something like $9 for approximately a litre, and we were going through it pretty quickly).

Eco-friendly Weed Killer
Homemade natural herbicide

Online I found a recipe. All it uses is vinegar, salt and a bit of dish soap (I use biodegradable soap). The only other ingredients you need are a hot, sunny day and a spray bottle, and it works exactly the same way as the commercial stuff that cost 10x as much!

Eco-friendly Weed Killer

Environmentally friendly weed killer:

  • 1 litre of white vinegar
  • 1/2 cup of table salt
  • squeeze of biodegradable dish soap (this helps the solution stick to the plants)
  1. Mix together the ingredients until all the salt is fully dissolved.
  2. Pour into a good quality spray bottle. You might want to get a pump spray bottle (one that allows you to pump pressure into it) from a garden centre, if you’re doing a lot of spraying — it will save your hands from a lot of squeezing.
  3. Generously spray your weeds on a hot, sunny morning. The sunshine will help do the work of drying out the foliage and killing it.

Note that this stuff is not selective. If you spray it accidentally on your lawn, you’ll kill the lawn. Also note that some plants with thicker stems might require a couple treatments to kill them completely. It works best when weeds are small and tender, so pull out bigger weeds and spray small ones before they get big. I find I have to do this a few times each summer to control the little ones that like to creep up through the patio stones. I’ve also read that the salt can contaminate the soil for up to two years, making it harder to grow things you want to grow in it, but I have only ever used this solution on weeds that insist on growing in our patio stones, and since these are exposed to road salt all winter, I think they’ve adapted to the salinity.

Finally, and unfortunately, I’ve found that the salt is not so kind to the inner workings of the sprayer, and while I rinse and clean it thoroughly and pump clean water through it a lot afterward, the metal parts still tend to corrode. So obviously a plastic bottle with no metal parts is best, but probably hard to find.