Biocast Product Information

What is Biocast?

Biocast+ is a concentrated liquid vermicast biostimulant. That means that it’s an extract of worm cast (worm poo) which you add to water for convenient and flexible application to plants, in order to improve their health. It comes in two parts.

“A plant biostimulant is any substance or microorganism applied to plants with the aim to enhance nutrition efficiency, abiotic stress tolerance and/or crop quality traits, regardless of its nutrients content.”

Jardin, 2015

Part A

Part A is a living liquid with all the goodness of worm cast. Our production process focuses on proliferating beneficial microbes and enhancing natural plant-stimulating compounds which are created by the worms and microbes. It contains:

  • High counts of beneficial, plant-relevant fungi, bacteria and protozoa. Think of these as the workforce for your plant, shuttling nutrients, competing with microbial pests, and creating a favourable soil environment. They are fully stabilised and in a semi-dormant state in the Biocast bottle.
  • Fungally-dominant. Generally fungus (such as mycorrhizal fungi) is the microbial group most damaged and depleted in our growing environments, giving plants a positive response when it is added back in.
  • Plant-stimulating growth hormones. These are hormones which encourage plant growth, for example by stimulating new root growth.
  • Enzymes. These are released by the microbes to dissolve minerals and make them plant available.
  • Autoinducers. These are signalling molecules used for microbe-microbe and microbe-plant communication.
  • High amounts of fulvic acid. Fulvic acid helps to convey minerals through the cell wall, enabling more efficient utilisation by the plant, making it ideal for foliar application.
  • Small quantities of nutrients, in plant-available forms. This is not a fertiliser. The point is to use the microbes and their byproducts to unlock the nutrients already in the soil in a balanced way that is right for the plant. This makes Biocast safe to use on all plants, even natives.
  • No other additives – all compounds are the work of the worm and associated microbes. We’re not second guessing Nature!

Part B

Part B is a biological catalyst to wake the microbes from dormancy and put them in a state of proliferation at the time of application. It consists of a complex protein to feed the fungi, and a complex carbohydrate to feed the bacteria. All ingredients are naturally derived and certified organic.

How is Biocast made?


Firstly, we collect raw materials and precompost them to Australian standards. This kills weed seeds and pathogens.


Secondly, we feed the compost to our worms, who live in big continuous cast harvest beds. We collect the finished worm castings from the base of the bed without disturbing the workers.


Finally, we extract the goodness of the cast into the liquid in a brew using rainwater collected onsite.

Quality assurance

 At Island Biologicals we are proud to produce a high quality, reliable product. We do this by using the same ingredients in the same ratios at each step. We use set amounts of cast, water and time in the extraction process. Pre-composting is an important part of stabilising the microbe populations. We undertake regular microscopic review of Biocast to check all is as it should be, and we get annual independent laboratory testing.