Natural Weed Killers: The Ultimate Guide

As environmental consultants in Melbourne, we understand how difficult it can sometimes be to manage the weeds in your garden effectively without compromising your plants. Synthetic weed killers tend to be effective – and they’re not necessarily bad to use – but they do have their downsides – especially if you’re growing your own produce. If you have pets wandering around your garden, then you definitely don’t want them eating anything that has chemical weed killer residue on it.

On top of this, if you have allergies or asthma – then, depending on the product, they could be harmful to you. That’s why we recommend using natural weed killers – and we’re going to spend today telling you about some different ingredients, combinations and preventatives that work a treat.

Boiling water

Believe it or not – but boiling water will kill weeds, or, more specifically – it’ll burn them. Pour the water over the weeds you want to kill, and they’ll die away – leaving no residue behind. This is highly effective and easy to do as it’s literally just boiling water. This option is best suited for large conglomerates of weeds.


Vinegar is great for killing weeds, as it can be a herbicide. You can go about this in two ways. For minor weeds, the vinegar you have in your kitchen should be sufficient when applied directly and plentily. If you’re facing a larger growth – then there is specific horticultural vinegar that you can pick up from Bunnings.

This product’s higher acetic acid content helps kill weeds. It’s important to note that you should avoid using vinegar on rainy days as the water will wash it away. The sun will make the vinegar more effective so be sure to apply it on a sunny day.


Salt will destroy salt and concrete. Whilst it is a weed killer – it should be used with care. If any salt gets on your driveway or pathway then you should wash it off as soon as you can. Simply apply the salt to the leaves of the weeds and they’ll begin to wither. Combine it with water to turn it into a more effective spray.

If you’re looking to really clear out a large area, then our Melbourne-based environmental consultants recommend mixing salt with vinegar in a spray to really do some damage to the weeds. These two ingredients are great at drying out the weeds – and, as we mentioned earlier, doing this on a sunny day where the sun can enhance this process is ideal.

Dishwasher detergent

Add dishwasher detergent to your natural weed killer to give it some extra power. It will act as a surfactant – breaking down the waxy coating that some plants produce to protect their leaves. The easiest and most effective example would be adding this to a salt and vinegar mix. The surfactant will ensure that the natural weedkiller cocktail sits on the plant (where it is most effective) instead of being absorbed by it.


This technique really only works for low-growing weeds or as a preventative measure – but it’s very effective, not to mention economical. Simply lay sheets of newspaper over the weeds (or over the area you’d like weeds to not grow). The lack of sunlight will stunt the growth and eventually kill them.

Put mulch on top of the newspaper as well to help prevent new weeds from growing. Since newspaper is a compostable item and great at decomposing – you can leave it under the mulch, and it’ll provide nutrients to your soil. This makes newspaper a double-pronged tool as it can really help your garden in two different ways.

Edging and barriers

Installing physical fences and barriers around your plants is a great way to stop weeds from growing. Whilst it’s not a solution for already-established weeds – it is a long-term preventive that is highly effective and also adds a great design element to your garden.

Looking for environmental consultants in Melbourne?

Keeping weeds out of your garden can be safe and cost-effective if you know how to go about it. We hope that you can take something out of our guide to natural weed killers. Using fewer chemicals can also mitigate build-ups in your garden or your land. If you do think your soil has become toxic – then you might need to enlist the help of Alpha Environmental.

Our Melbourne-based environmental consultants are fully trained, qualified and equipped to handle a variety of environmental tasks including soil testing, Phase I, II & III ESA’s as well as groundwater assessment.

If you’d like to get in touch with our environmental consultants in Melbourne, then please give us a call on 1300 039 181. Or, you can contact us by filling out the enquiry form found on our website.