We keep hearing the same thing from people who want to stop using Roundup: “Okay, but what do I use instead?”
It’s a fair question. Most of us didn’t grow up reading herbicide labels or studying plant biology—we just want something that works, isn’t toxic, and ideally won’t cost the earth (in more ways than one).
That’s why we’re creating this growing library of glyphosate-free options—so you can make up your own mind about what’s right for your garden, school grounds, or green space.
One product that recently came onto our radar is Weed Blast Concentrated Natural Weedkiller, made by Green Kiwi. It’s locally developed, doesn’t use glyphosate, and claims to be safe for kids, pets, and pollinators. Let’s take a closer look.
See It in Action
We can talk about effectiveness all day—but sometimes it helps to see for yourself. Here’s a short demo from Green Kiwi showing Weed Blast in action on a weedy patch of ground:
It’s not a high-budget production, but that’s kind of the point. This is a real-world spray, made by a local company, doing what it says on the label. And while every property is different, this gives you a feel for how it performs on contact.
What Is Weed Blast—and What’s in It?
Weed Blast is a concentrated herbicide that relies on strong fatty acids (we assume things like pelargonic acid or similar) to kill weeds by breaking down their cell walls. Sunlight helps speed up the process, which makes timing your application important.
The company says it’s effective against a wide range of common weeds:
Dock, ragwort, dandelion, clover, grasses, oxalis, hydrocotyle, moss, mould—even tougher customers like old man’s beard. It’s also biodegradable and safe to use around pets and people once dry.
It comes in a few sizes, and a 2L bottle goes a long way—up to 100L of spray depending on how strong you mix it.
We like that it’s made in New Zealand. Supporting local solutions matters.
Yes, It Works. But…
Like most contact-based weedkillers, Weed Blast doesn’t move through the plant systemically like glyphosate does. That means:
- It kills what it touches (especially leaves and stems)
- But roots, bulbs, and deeper systems may bounce back unless you reapply
In other words, stubborn weeds might need a few follow-up sprays.
You’ll also get the best results on a hot sunny day, when the fatty acids can do their work quickly. It’s not a “spray and forget” solution—but that’s the trade-off for ditching the synthetic chemicals.
Any Downsides?
We want to be as upfront as we can—because no product is perfect.
Here are a few things to keep in mind:
- We don’t know exactly what’s in it. The label says “fatty acid-based,” but doesn’t list the exact ingredients or their concentrations. That makes it tricky to fully assess safety or compare to other products.
- It might irritate skin or eyes. Like most strong acids (even natural ones), it should be handled with care. Protective gloves and eye gear are a good idea.
- Effectiveness depends on weather. Cloudy or cool days reduce its impact, and rain shortly after spraying will wash it away.
- It doesn’t kill roots. Persistent weeds like kikuyu or convolvulus might grow back unless repeatedly targeted.
- Cost. Natural products are rarely as cheap as conventional herbicides. While the concentrate goes a long way, upfront costs can be higher.
Still, for many people, the trade-off is worth it.
Where to Find It
Weed Blast is available online from Green Kiwi and possibly from select garden stores.
We recommend checking the dilution guidelines and safety instructions carefully before use. You’ll also want a reliable sprayer, as some home-use sprayers can clog or struggle with concentrated products like this.
Final Thought
We don’t sell Weed Blast. We don’t get anything if you buy it. One of our supporters simply told us, “This is what I use—and it works.” So we looked into it.
Is it the answer for every weed problem? Probably not. But it’s one more glyphosate-free option you might consider adding to your toolkit.
We’re profiling more alternatives in the weeks ahead—like Contact Organics—because change doesn’t start with regulators. It starts with us.
Click here to learn more about natural alternatives to glyphosate.
Disclaimer:
This article is provided for informational purposes only and does not constitute an endorsement. We’re sharing this information to help raise awareness of glyphosate-free alternatives. No More Glyphosate NZ has no financial ties to the makers or sellers of this product. We simply believe New Zealanders deserve to know what safer options exist — and we encourage everyone to do their own homework before making changes.
Image Source & Attribution
The feature image on this page incorporates a photo by annazelena, which was then combined into a custom graphic using Canva. Explore their full portfolio here: https://www.123rf.com/profile_annazelena.
