Benefits of Worm Castings for Stronger, Healthier Plants and Better Crops

When composting worms munch their way through rotting organic material like kitchen scraps and turn them into worm castings they silently, bit by bit create an elixir of life for soil and plants that can revive spent soil and support plants to thrive from seeds to harvest. 

Some of the benefits of worm castings include adding nutrients in a readily available form over time, increasing soil and therefore plant health, increased pest and disease resistance and better water retention.

Taking the bigger picture into account, namely long-term soil, people and plant health, worm castings outperform artificial fertilizer thanks to their complex effects on soil health.

It’s the difference between eating wholesome organic food and existing on a diet of pills. The body will benefit from natural, biologically complex and healthy vegetables but will start to show signs of deficiencies if given only extracted minerals and vitamins even if those are beneficial to some degree.   

What are Worm Castings?

Worm castings, vermicasts, vermi castings, vermi-compost are all different names for worm poop, specifically worm poop from composting worms.

Composting worms play a huge role in turning fresh organic matter into stable organic material full of microbial life. They don’t do this alone but their food needs to have loads of microbes and fungi on it to make the material soft enough for worms to eat as they don’t have teeth to chew. In other words, composting worms feed on rotting, usually plant-based organic matter. Therefore, all the plant-based stuff that is past its sell-by-date and is turning into a mush is heaven for earthworms. 

They thrive on the micro-organisms there and what’s more, grind the food further down to very fine particles and add more beneficial enzymes and microbes while it passes through their gut. The earthworm is like a natural bio-reactor that improves and speeds up biodegradation and delivers worm castings, a super-refined compost that can jump-start and support numerous biological processes necessary for plants to grow and thrive.

Worm Castings as Fertilizer

Composting worms such as the red wiggler concentrate trace minerals and nutrients into water-soluble forms so they can be slowly and steadily absorbed by plants. 

How much nitrogen, potassium or magnesium, calcium or phosphorus does it contain? That will depend very much on what the worm was feeding on. 

In fact, it is very likely that the worm compost out of your worm bin will not necessarily compete with off-the-shelf synthetic fertilizer on an element by element basis. However, and this is hugely important, this doesn’t mean it’s less effective to grow healthy plants and improving the soil at the same time. 

This is because chemical fertilizers add chemical elements but nothing else. But plants need a healthy, biologically active environment. Chemical fertilizers do not add any microbial life to the soil, in fact they often kill it. This starts the paradox downward spiral of requiring more and more fertilizers and decreasing soil fertility. 

A chemical fertilizer is just that: a one shot wonder delivering nutrients just once and the rest is washed away, polluting groundwater and waterways, leaving behind a biological desert.  

Organic fertilizer such as worm castings on the other hand add minerals and nutrients in addition to a vast amount of beneficial microbes, bacteria in a much gentler way whilst also promoting a biologically more diverse and healthy soil.

Worm Castings as Soil Enhancer and Amendment

A Biologically More Diverse And Healthy Soil

Vermicastings contain beneficial bacteria, enzymes, microbes, fungi and nematodes. Some of those you would find in any compost, others only occur when compost has been digested by earthworms. The added microbes and enzymes allow vigorous growth and boost beneficial plant – soil relationships

Far Fewer Pathogens and Better Disease Resistance

There are several processes at play in vermicomposting which result in far fewer pathogens in worm castings compared to traditional compost. So far, research into the benefits of worm castings and the underlying processes and mechanisms is only scratching the surface of the underlying processes.   

Composting worms feed on fungi, extract toxins and aerobic bacteria. Some of these are potentially harmful and toxic for plants but do not survive the low oxygen levels in the worm’s gut.

Another reason could be that worm castings do not build up heat, allowing disease suppressing micro-organisms to survive and outcompete pathogens. 

Stabilizing pH level

Worm Castings themselves are chemically stable, yet have a very active, beneficial microbial life.

The ph level is 6.9-7. This neutral ph level allows plants to grow in soil which is either too acidic or alkaline. In this case, vermicasts act as a facilitator for plants and allow them to absorb nutrients which they couldn’t do in soil with too high or too low pH level. 

Higher Level Of Humic Acid For Better Soil

Humic acid is a part of humus, the fertile carbon-rich matter that generates the lovely smell of a damp forest floor after rain and looks dark and stimulates a diversity of micro-organisms. 

The main benefits of humic acids are increased water retention and nutrient absorption, both of which in themselves stimulate higher plant growth. 

Soil rich in humus and therefore humic acids make for a better soil structure in which roots can spread out more easily and grow stronger. This is beneficial for trees, shrubs, vegetables and flowers – so no matter what you grow in your garden, worm castings will be beneficial. 

Better Water Retention 

Regardless of the kind of soil you have, worm castings are likely to diversify the particle size and improve water management in the soil.  

The organic matter composting worms feed on is ground to finer particle size in their gut. Finer particle size provides more surface area for water to attach to and more water can be stored and slowly released to plants over time. 

In addition, worms add humic acid which results in worm castings that can absorb, retain and slowly release water to the plant. 

Safe, Clean And Odourless

Vermicasts are chemically stable and pH neutral. Finished worm castings therefore have a pleasant, forest floor smell. 

They also don’t require a curing or ageing period like typical compost. 

All of this means it’s easy to use and apply straight out of the worm bin or bag if purchased.

How To Use Worm Castings

Worm castings are easy to use in pots and gardens. The castings can be applied directly to seedling potting mix, established plants or used in worm casting tea.

Bottom Line

Benefits of worm castings have been well documented with regards to fertilization, increased water retention and pest/ disease resistance.

Vermicasts are a safe, renewable, 100% organic resource every keen gardener should employ.

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