Soil Microbe Booster
Frass and Biochar
Feeds the soil rather than just the plant, built on frass, an all-natural fertiliser made from insect manure.
- 240 million CFU per gram of frass
- Up to 200x the nutrients of castings
- NPK 4:2:2, plus iron, copper and zinc
- Chitin activates plant defences
For Christmas, order by 16 December, or 18 December in WA. All dates
A blend of frass and biochar that feeds the soil rather than just the plant. Frass is an all-natural fertiliser made from insect manure, bursting with nutrients and good microbes. Biochar is a charcoal-like material made by heating raw matter without oxygen. Separately they do good things. Together they bring a tired potting mix back to life, and the numbers are published rather than implied: 240 million microbes per gram and an NPK of 4:2:2.
Key Features
- Microbial load. 240 million colony forming units per gram of frass.
- Nutrient density. Holds up to 200 times more nutrients than worm castings or compost, with more microbial diversity.
- The analysis. NPK 4:2:2, plus iron, copper, zinc and other trace nutrients.
- Chitin. From insect exoskeletons, it activates the plant's natural defences against pathogens like root rot and increases nitrogen availability.
- Biochar. Improves the soil's capacity to hold nutrients and water, buffering both dry spells and overwatering.
- Credentials. Carbon-negative, sustainably sourced and Australian made.
Pūrē Standard
- It feeds the soil, which is the part most plant care forgets. Liquid feeds hand the plant nutrients directly. This rebuilds the biology of the mix so the soil can do its own job, which is a longer game and a better one.
- Carbon-negative, and that is not a small claim. Biochar locks carbon into a stable form rather than letting it return to the atmosphere. Combined with frass, which turns food waste into fertiliser via black soldier fly larvae, the whole product is a waste-to-resource story.
- The chitin is the clever bit. Insect exoskeletons trigger a plant's own immune response, so you are prompting the plant's defences rather than spraying something at a problem after it appears.
- Published numbers, not adjectives. 240 million CFU per gram, NPK 4:2:2, named trace elements. Very few soil amendments will give you a figure.
- Not vegan, and we would rather be upfront. Frass is insect-derived, made from black soldier fly larvae. That is why this does not carry our Vegan tag.
Overall score:
| Category | Score |
|---|---|
| Performance | ⭐⭐⭐⭐☆ (4.5/5) |
| Low-Tox & Material Safety | ⭐⭐⭐⭐⭐ (5/5) |
| Sustainability | ⭐⭐⭐⭐⭐ (5/5) |
| Manufacturing Transparency | ⭐⭐⭐⭐☆ (4.5/5) |
| Packaging | ⭐⭐⭐⭐☆ (4/5) |
How to Use
- Repotting. Stir through new potting mix at 1 to 10% of the mix by volume, targeted at the root zone.
- Existing plants. Sprinkle around the root ball as a top dressing, roughly every three months.
- Compost. Blend in at 1 to 10% by volume to speed up decomposition.
- Timing. It can be used year round.
- White mould. Any that appears is natural and not harmful, and it disappears once the booster is used.
Product Details
- Ingredients. Frass (insect-derived fertiliser, from black soldier fly larvae) and biochar. NPK 4:2:2, with iron, copper, zinc and other trace nutrients, plus naturally occurring chitin.
- Size. 500ml.
- Credentials. Carbon-negative, sustainably sourced, Australian made in Melbourne.
- Not vegan. Frass is insect-derived.
- Shipping. We hold this in stock in Perth and ship it within Australia. Quarantine rules can restrict soil products into the Northern Territory and Tasmania, so please contact us before ordering to either.
Choose options
For Christmas, order by 16 December, or 18 December in WA. All dates
Our Take
Plant Runner is made by people who keep plants alive for a living. This booster feeds the soil rather than just the leaves, which is the part most plant care forgets. A quiet fix for tired, sulking indoor plants.
Pūrēly Organic
Good to know
Frequently asked
What is frass, exactly?
An all-natural fertiliser made from insect manure, specifically black soldier fly larvae fed on food waste. It holds around 240 million microbial colony forming units per gram and up to 200 times more nutrients than worm castings or compost, with more microbial diversity too.
What does the biochar do?
Biochar is a charcoal-like material made by heating raw matter without oxygen. It boosts the soil's capacity to hold nutrients and water, which buffers plants through both dry spells and overwatering.
Is it vegan?
No. Frass is insect-derived, so this does not carry our Vegan tag. We would rather tell you plainly than let the plant-based framing imply otherwise.
How do I use it?
When repotting, stir it through new mix at 1 to 10% of the volume, targeted at the root zone. For existing plants, sprinkle it around the root ball as a top dressing every three months or so. You can also blend it into compost at 1 to 10% to speed up decomposition.
There is white mould on it. Is that a problem?
No. It is natural and not harmful, and it disappears once the booster is used.
Can it be shipped anywhere in Australia?
Not everywhere. Plant Runner cannot ship soil products into Western Australia, the Northern Territory or Tasmania due to quarantine restrictions. If you are ordering to NT or TAS, please get in touch before you order.
