Liquid plant biostimulant from vermicompost tea

worm castings tea

When I worked in either hydroponic or organic professional greenhouses for many years, one of the problems of applying the solid form of the high quality compost such as vermicompost or worm castings inside the greenhouse was, it would leave dirty and messy debris everywhere on the floors, in the pipes, and at the filters. That’s the practical issue and has to be solved to support the natural way of farming or organic farming. And it’s important, as the application of the worm castings shows amazing results in the growth and production of plants.

All greenhouse growers are practical and use the right calculation of the costs and benefits to support the homogeneity of the growth rate and the optimum yield of the horticultural and agricultural plants. The most valuable critical comment of using worm castings for a large scale application is that the matrix content of the castings fluctuates. Results depend on the organic wastes used as a feedstock of making vermicompost, so the quality and quantity of the nutrients are inconsistent. That means worm castings can not be categorized as a fertilizer, but we call it a plant additive or biostimulant.

According to the European Biostimulants Industry Council (EBIC), crop biostimulants include diverse formulations of compounds, substances and microorganisms. When applied to plants or soils, they improve crop vigor, yields, quality and tolerance of abiotic stresses. Biostimulants operate through different mechanisms than fertilizers, regardless of the presence of nutrients in the products, so they are complementary to crop nutrition. The application of biostimulants can significantly reduce the use of chemical fertilizers and pesticides up to 50%.

The application of solid form of worm castings on the lawns, vegetable and fruit farms in the field is no problem as the vermicompost can be mixed with the soil. The worm castings are rich in beneficial soil microorganisms, fulvic and humic acids, plant growth regulators or plant growth hormones, and available nutrients that will make the plant much healthier. The density of the composting worms or red wigglers to produce the high quality of worm castings or vermicompost made from organic wastes should be at least 0.5 – 1 lb. per square foot (2 – 4 kg. per square meter).

Recently, the liquid form application of the worm castings tea or vermicompost tea has become popular, because it’s more efficient and effective for the plants, and the cleanliness of the greenhouse can be controlled. The application of liquid form or the vermicompost tea to the plant requires less quantity of the worm castings compared to the solid form of the vermicompost. The vermicompost tea can reach the stems, leaves, and roots faster. Research studies have shown that filtering the finished vermicompost tea before application to the plants reduces the risk of dispersing weed seeds that might be found in solid vermicompost.

In addition, the vermicompost tea is more active than solid vermicompost and the beneficial microorganisms in the vermicompost tea suppress the population of plant pathogens. Possible mechanisms for the plant disease suppression by vermicompost tea may be antagonisms between plant pathogens and beneficial soil microorganisms, competition for plant pathogens infection sites, or destruction of plant pathogen propagules such as spores.

The other important benefits of the vermicompost tea have been documented in many scientific publications. Application of the vermicompost tea will speed-up the germination and healthier growth of the horticultural and agricultural plants. Although available nutrients are present in vermicompost tea, these are not the main reasons for the increase in germination and growth of the plants. The beneficial microorganisms, plant growth regulators such plant hormones, fulvic and humic acids are the most probable cause for germination, growth and yield increases of the plants.

The process of making vermicompost tea can be as simple as 123. Place the pure and high quality of vermicompost in hessian sack or fabric bag, put the sack or bag in the drum or container and fill the container with non-chlorinated water. The ratio of the vermicompost : water can be 1 : 10. Agitate and aerate the liquid really well for at least 24 hours and keep soaking the vermicompost in the water (see the photo above). A small amount of molasses can be added to the system as a source of energy for the beneficial soil microorganisms to thrive. Stir and filter the vermicompost tea, then it’s ready to spray to the plants.

Please visit our website at to buy the high quality worm castings or vermicompost, or for instructions to make it using the resource-organic waste management available in your location.

– Bintoro Gunadi

BRW card back
  1. erol ozalp said:

    we are interesting,liquid vermicompost machinery line and technical adviser

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