Worm castings, why, what & how.

Worm castings, why, what & how.

Worm poo? As a fertiliser? Yes! While it might sound gross at first, worm castings are considered as a staple in the world of soil. There are many advantages to worm castings. 

Zoomed in shot of worm castings texture

Why worm castings?

There are many advantages to worm castings. 

  • it is a 100% organic fertiliser that is also effective against many pests like spider mites and aphids. 
  • It is packed with lots of nutrients and minerals that help boost the plant’s growth. 
  • It also retains moisture well, similar to coco coir. It is a great alternative to chemical-based products used in most potting soils. 
  • Worm castings also release nutrients slowly, meaning they can’t burn your plant! 
  • It improves soil aeration and drainage. 
  • Worm castings have a better humus level, and better fertilisation potential than regular compost. 

While worm castings are great, there are also some disadvantages. 

  • Worm castings take a pretty long time to make if you do it yourself, about 90 days to a year. 
  • It is also a bit more expensive than chemical fertilisers, but they are on the cheaper end of the spectrum when compared to other organic fertilisers! 

What are worm castings

Worm castings act as an organic form of fertiliser, produced from earthworms. Worm castings are created in compost bins. They act as a natural fertiliser that can both be bought and created yourself. 

Worm castings tea

Tea?! From worm castings? Yes! If you don’t feel like adding actual worm castings to your soil, consider making a tea. By just adding a few spoons of worm castings to some lukewarm water, you will have a fertiliser tea full of nutrients you can use to give your plants a boost.

How much worm castings to add to the soil?

This depends on a number of reasons, while too much is never a good thing, quite a big part of your soil mix can consist of worm castings. There are a few things to consider. 

  • Worm castings hold a lot of moisture, don’t add more than 10% for cacti & succulent plants. 
  • Young & sensitive plants need about a ratio of 1:2 worm castings to soil
  • For most other plants, a ratio of 1:3 or 1:4 worm castings to soil is perfect.

I have had success with mixing up to a ratio of 1:1, however the soil will retain more moisture than usual potting mix. Take this into account when watering.

How are worm castings created

Worm castings are created in compost bins, also known as worm bins. Things like leaf litter, garden waste and kitchen scraps can be thrown in as food for the worms, the worms eat through the waste and leave you with piles of worm castings to use for your plants. 

Worm castings

Critters in your worm castings

Worm castings can (as you might have guessed) live worms. This is not a problem! Along with isopods & springtails that also tag along they will attack rotting plant matter, dead roots and other things your plant doesn’t like. They leave the living parts alone and turn the thrash into plant food! 

How long does worm castings stay fresh?

Worm castings last around 6 months, this is also the time the worm castings stay active as a nutrient in the soil. You can replenish the worm castings in the soil by removing the top 20% of the soil, replacing it with worm castings and mixing it in carefully by hand. When you water it, nutrients will flow down onto the roots!

Purchase your worm castings here.

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1 comment

I would like to know more please.


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