“Another great product from the Dr.Greenthumbs team.” – Jason Smith
“…noticed a massive decrease in gnat numbers! Happy days!” – Josh Van Limbeek
What Exactly Is Insect Frass?
Insect frass is the nutrient-rich castings of black soldier fly larvae. Pack it full of beneficial microbes, a naturally high chitin content and a balanced N-P-K profile, and you’ve got an organic powerhouse that out-classes ordinary compost or worm castings for microbial diversity and plant-available nutrition.
Why Gardeners Swear By Frass
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Explosive microbial life – up to 20 × more biology than worm castings means faster nutrient cycling and healthier soil.
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Chitin triggers plant immunity – roots detect chitin fragments and switch on natural defence pathways against pests and pathogens.
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Improved soil structure & water-holding – frass feeds the fungi and bacteria that create fluffy, well-aggregated soil.
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Eco-friendly & odour-free – produced from food-waste-fed larvae, it turns trash into garden treasure.
Pro Tip: Pair frass with a quality living-soil mix like TurboDirt for an instant biology boost.
How to Use Dr Greenthumbs Insect Frass
|
Setting |
Rate |
Frequency |
|
Potted plants |
1–2 Tbsp over the surface, water in |
Every 4-6 weeks |
|
Garden beds |
50–100 g / m², mix into top 5 cm |
Each season |
|
Fruiting trees |
250–500 g around drip line |
Spring & Autumn |
|
Potting mixes / hydro media |
15–30 g per 30 L |
At pot-up |
(1 heaped Tablespoon ≈ 3-4 g)
Frass vs Worm Castings: The Quick Low-Down
|
Insect Frass |
Worm Castings |
|
|
Microbial density |
⭐⭐⭐⭐⭐ |
⭐⭐⭐ |
|
Chitin content |
High |
Nil |
|
Application rate |
Low (economical) |
Moderate |
|
Odour |
Neutral |
Earthy |
|
Pest-control boost |
Yes |
Minimal |
If you want to see how worm castings perform on their own—and where frass outshines them—our Worm Castings Australia: The Complete Gardener’s Guide breaks down the biology, nutrient release and real-world results.
Step-by-Step Application
- Top-dress & water – Sprinkle the recommended rate and water immediately to activate microbes.
- Brew a frass tea – Soak 1 cup of frass in 10 L of de-chlorinated water for 24 h, then drench soil or foliar-spray. And if you're stacking this tea with other organic inputs, the Kelp Meal: Australia’s Ocean-Powered Fertiliser (2025 Guide) shows how kelp hormones pair with frass to supercharge stress resistance and growth.
- Charge your compost – Add a handful per 20 L of compost to accelerate decomposition.
Frequently Asked Questions
Q. Is insect frass safe for edibles?
Absolutely. It’s an organic input and leaves no harmful residues.
Q. Will frass attract pests?
No. In fact, the chitin helps plants deter sap-sucking insects.
For growers chasing an even stronger phosphorus and calcium boost—especially in fruiting crops—our Seabird Guano: The Ultimate Aussie Grower Guide 2025 explains how to integrate guano without upsetting soil balance.
Q. Can I overdo it?
It’s pretty forgiving, but stick to the rates above—less is more thanks to the dense biology.
Ready to Super-Charge Your Soil?
Grab a bag of Dr Greenthumbs Insect Frass (High Calcium & Chitin) today and see the difference for yourself. Your tomatoes, chilies and citrus will thank you!
Happy growing from the team at Dr Greenthumbs—proudly helping Aussie gardeners cultivate thriving, chemical-free gardens since 2012.
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