By Talia Tinari

The bag arrives in the mail, and I quickly open it to make sure they are still alive. They are! They are a squirming, writhing ball of Red Wriggler worms. Their Latin name is Eisenia fetida, and among many other common names they are also known as the Californian earthworm. Native to Europe they are now found all over the world.  They live above the soil and are specifically adapted to eating decomposing organic material. Red Wigglers are a different species than the longer red earthworms (Lumbricus rubellus) that live below the soil.

This is my first foray into vermiculture, or vermicomposting, defined as “the use of specially bred earthworms, especially to aerate soil and convert organic matter into compost.” Vermiculture is an excellent way to compost in small garden spaces.

I tie up the bag and leave to run a few errands before taking them to their new home in the Santa Monica Community Gardens. Not an hour later I return to find a kitchen table and floor covered in red wrigglers, (and two bewildered dogs).

So, it is best to have your worm habitat established before ordering your worms and be ready to take them directly to their new home as soon as you receive them.

Worm habitat

There are several types of bins on the market that can easily be purchased online. They are usually composed of three or more layers.  The top layer is for compost, the middle layer for bedding, and the bottom layer for the collection of worm excrement, or ‘castings’ and the liquid produced from them, known as worm ‘tea’.

A worm bin can also be made from something as simple as a Rubbermaid bin with a top.  Holes can be drilled at the top of the sides for aeration. The compost can be deposited at one end, with the bedding in the middle, and castings then collected from underneath the bedding and compost.

Black and white shredded newspaper, cardboard or coconut coir can serve as bedding. The bedding must be moistened, but not fully saturated to create an ideal environment for the worms.

Your worm bin should be out of the sun and positioned where it won’t get too wet, in the off chance of a heavy rain.  Some people keep a worm bin in a garage or on an apartment patio, but I found that the collection of the castings and periodic cleaning of the bin was too messy, and would have been almost impossible without a hose nearby.

What do worms eat? What can be composted and what cannot?

Your worms should have a mix of greens (nitrogen-rich organic material) and browns (carbon-rich materials such as dried leaves and wood ash). In place of dried leaves or wood ash, brown coffee filters and untreated brown paper towels work well to fulfill the brown component. Nitrogen is important because it is found in chlorophyll, the compound that makes plants green and helps carry out photosynthesis (the process that converts the sun’s energy and makes plants grow).  Carbon is an element that is essential to healthy soil and sustaining all of life.

So, specifically, all uncooked fruit and vegetable waste, including citrus peels can be composted. It is also important to chop the greens into smaller pieces. For example, if you are composting a broccoli stalk, chop it first to avoid decomposition before the worms are able to eat it. Other peels and skins, such as banana peels and avocado skins can be composted but the avocado pit and other pits, such as those from stone fruits cannot.

Coffee grounds and their filters, tea and tea bags can be composted.  Clean, crushed, dry eggshells can also be composted.  Worms do need some ‘grit’ in order to digest their food.  Sand or fine gravel can be added to the bedding, but I found that eggshells pulverized in a blender worked just as well.

Cooked meats and dairy cannot be composted; neither can pet waste, as most dogs and cats are carnivores.  Meat and dairy will not be eaten by the worms and will attract unwanted rodents.

After they eat

In a couple of weeks they worm colony should produce beautiful brown tarry curds.  It is usually necessary to drain off the liquid and then scrape up the castings, which will have varying degrees of wetness. Sometimes the worms find their way into the castings, and they should be removed and put back in their bedding. This is a messy job. Wear gloves.  The castings and tea can be stored in recycled glass jars for when you are ready to fertilize your garden. Vermiculture is a sustainable process, providing a rich and natural source of fertilizer for small gardens.