Wiggling worms work wonders with waste.
by Simon Hart, The Organic Mechanic
Today’s gardeners all want to increase our land's fertility and increase our green efforts at the same time.
With that as our aim, there is one option that stands out as a must-have for all backyard gardens — worm castings.
Worms break down all sorts of organic material during their digestion process. This process, known as vermicomposting,
will give you some of the highest quality soil amendments available and help create a more technical and successful
garden experience, while conserving resources.
Current research show extremely complex benefits from the use of worm castings in agriculture.A green technology,
vermicomposting is the epitome of the slogan: reduce, reuse, and recycle. Our growing knowledge of these largely
unnoticed creatures in the soil shows a fascinating connection between the worms and overall ecosystem health.
Their effects on soil biology, nutrient availability, and the complexity of their decomposition of organic materials,
are some of the things currently being studied.
Although we are just starting to understand the relationship between earthworms and healthy soils,
worms have been fascinating people for millennia. For example, Cleopatra, Queen of the Nile,
decreed that worms were sacred and not to be harmed. The Greek philosopher, Aristotle, declared them to
be the guts of the soil. The great biologist, Charles Darwin, who may have been best known for his theory of evolution,
started his scientific work looking at earthworms. He was fascinated by them and was utterly convinced that worms
were among the unsung heroes within the natural world. In 1881, he published his lifelong research on earthworms.
Given just a little space, time and knowledge, it is possible to grow your own castings. Not convinced that
it is worth the effort? Have a look at the benefits and then the actual work involved in growing worms and
supplying your own rich, microbial super-charged soil amendment.
Research shows that vermicompost stimulates plant growth even when plants are receiving optimal nutrition.
Improved seed germination, accelerated growth and development, increased productivity and yield are all
scientifically validated claims. Other benefits, such as disease prevention and the ability to repel
pests are possibilities; but there needs to be more study to understand the mechanisms behind these potential advantages.
When compared to regular compost, vermicompost stands out as the winner. Higher levels of plant-available nitrogen,
phosphorous, potassium, sulphur and magnesium make vermicompost nutritionally superior. Microbiology is also more
complex in vermicompost than standard compost. Why? Vermicompost is processed at a moderate temperature range that
never comes close to the 60 degrees Celsius or higher achieved in traditional “hot” (thermophylic) garden compost.
This means that your worm castings will have more microbes meant to live at normal temperatures than compared to
those in regular compost. Although the process is not entirely understood, it is also clear that worms release
more microbes than they ingest, meaning that they are actually creating microbes during their constant eating.
Many composters believe you need a temperature of 60 Celsius or higher to destroy pathogens. Surprising new
research results have shown that castings produced in a pathogen-rich environment actually contain no pathogens.
Dissections show that something happens within the first 5mm of the worm that completely removes pathogens.
Estimates say that there could be over 1,800 species of worms worldwide. Many of the worm castings available in retail
shops are produced by African nightcrawlers. However, this worm does have very specific growing requirements. A better
choice is Eisenia Fetida, more commonly known as a Red Wiggler, indigenous to most parts of the world.
This particular worm is extremely tough and adaptable, able to handle a temperature range from 0-35 Celsius,
and the eggs or cocoons can even survive short periods of complete freezing. This species is commonly used in
commercial vermicomposting and is easily accessed by hobby gardeners through internet sales and even some
municipal green waste programs.
Before you order your worms, you must ensure that they have somewhere to live. There are many small,
home-sized worm farm units available. Some are more efficient, some more complicated than others.
Remember that vermicomposting is a type of farming, not an industrial process, so bigger isn't necessarily better.
A savvy gardener will want to master the basics prior to a significant investment in equipment.
Some bins are even small enough to fit under the kitchen, and wherever placed, healthy worm bins produce no smell.
GIVING YOUR WORMS A HOME
To manage your worms properly, you need to consider five essentials:
- A hospitable living environment — The best worm farms have the best bedding. Things like straw,
peat moss, coir, newsprint, cardboard, and even dried leaves all make excellent bedding; and can provide
different benefits when blended together. You are looking to create a moist environment with lots of air
pockets and a high carbon to nitrogen ratio. I personally have found a blend of straw and coir to be an
excellent mix. A pH range of 5-9 is acceptable with a level of 7 being ideal.
- A good food source — Worms are what they eat, so their food source is very important.
Vegetable and fruit peeling are excellent, and coffee grounds are great when available. Kelp meal is a
good choice, but remember that worms are sensitive to salt. Corrugated cardboard is also a good food source
because of the high protein glue used to bind it. Commercially, there are many more food sources, including manures;
but for the urban gardener it’s fine to stick to what you might put in a standard compost bin.
- Adequate moisture — A damp environment is needed to get the job done and for the worms
to be happy while doing it. The moisture content in the bedding should be somewhere around 70-90 percent.
This means you may have to add water at the start; but as you pile the kitchen scraps into the bedding,
the moisture should balance out to a good range.
- Worms need to breathe — Ensure there is a good level of oxygen. If bedding becomes too compact
it will force worms out by creating an anaerobic environment, which kills worms and creates an odour that
you don't want in your garden.
- Protection from extreme temperatures — The Red Wiggler is a perfect worm for vermicomposting
because of its temperature range acceptance. However, you need to keep direct sun off your bin because
it can overheat the bedding. Remember, also, that direct sun is toxic to worms. Outdoor vermicomposting
does require some shelter planning, especially in Canadian winters that sometimes spill into the northern States too.
Adding grit to your bedding can help worms process more material. Inputs such as soil, powdered limestone,
rock dust, egg shells, and zeolite, can provide the abrasive material that worms use in their gizzards.
Note that all of these items will also provide extra benefit when added to your soilless mix as well.
My first experience with vermicomposting began last year when, to the horror of other members of the Greenstar team,
I placed a worm bin in my office. I was immediately reminded that if it started to smell that would be the end of it.
The pressure was on, so I put in my bedding and a half pound of worms and started the feeding frenzy.
I placed approximately 20kg of food waste in the bin over 14 weeks. I was amazed at how quickly the worms processed
material. And everyone in the office was stunned that there was essentially no smell other than a mild earthy aroma.
This first batch of quality vermicompost got me hooked, and I would like to pass this concept along as a
suggestion from one gardener to another.
Excitement is building and you want to use some of the black gold that has been growing in your worm bin!
The finished product will range from 10-50% of the original weight of the material. But don’t worry about this
perceived loss because the best ratio of castings to mix in your growing medium is about 10%.
You can add up to 40%, but over 40% seems to decrease its value, and castings can then actually slow plant growth.
It's fine either to use the worm castings as a top dressing or work it into your medium.
Without question, the addition of worm castings can provide gardeners with more vigorous plant development.
For those gardeners up for the challenge, small scale worm farming results in a burst of plant growth, while decreasing the
waste that leaves your house for the landfill.
Good luck with your first worm bin this season and may the resulting castings motivate you to build a larger worm farm in future.