Worm Compost and Worm Casts – is there any difference?
This article will hopefully explain the difference between worm compost and worm casts and the use and benefits of both, as the names suggest, both of these are produced by worms.
1. Worm compost
Composting worms live and feed on organic matter that range from fresh to really decomposed! this can be anything from natural heaps of leaves, dead grass and vegetation to the garden and kitchen waste we put in our compost heaps, bins and wormeries, as the material starts to break down it is invaded by a myriad of different bacteria, fungii and 101 different bugs and creatures it is these fungii and bacteria that the worms actually feed on, in doing so they continually move up and down through the layers looking for better food, somewhere to rest up and somewhere to lay cocoons (eggs). To enable them to do this they exude a mucuus allowing them to wriggle through the compost, this mucuus is full of benefits to plant root systems, of course, all the time they are feeding they have to get rid of their waste, basically worm poo and this is left in and eventually all mixed up in the compost, if the worms are removed before they have consumed (several times) all the organic material we then have “worm worked compost.”
2. Worm Casts
Worm casts are a different product entirely from worm compost, casts are essentially the pure poo from worms. When worms are living in a compost, they feed on it, if no more green waste is added they will eventually have eaten all the waste available, continually replacing it with an increasing percentage of casts, as the waste becomes less available they will also feed on the casts themselves, in fact, they can do this many times over (waste not – want not!) eventually all the material left is almost entirely worm poo, this is proper worm casts.
The use and benefits of each.
We can now see that there is a difference between the 2 products and this means there is a difference in the use and benefits of each.
It is easier to understand if we deal with worm casts first, as originally stated, casts are produced only when the whole amount of waste (or near enough) have passed through the worm, in doing so it is ground up into tiny particles and mixed together with different secretions, the resulting casts are not necessarily high in nutrients as often claimed but after they have “matured” they are absolutely jam packed full of hugely beneficial bacteria, fungii and other organisms. these qualities are utilised directly by plants via the root system providing the plants are already planted in soils with good structure, that is the job of the worm!
Now we can see that worm compost, due to its lower levels of processed material is not going to work in the same way as casts directly with plants, however, being a compost, they create a highly beneficial environment regulating air and moisture around the root system of plants particularly where the existing soil structure is not so good this in turn allows the roots to benefit from the casts within the compost. Because there is still compost (uneaten worm food) in and around the plant roots this will encourage worms to stay or even move into the area to feed and in turn they will raise the level of casts for the plants to utilize! As can be seen, it is very important that the right balance of processed and unprocessed material in the compost is achieved otherwise the conditions created for the plant will be wrong.
Whichever you use, worm worked compost or pure worm casts your plants can only benefit.