Written by Sarah Worley

Imagine creating your own nutrient rich soil booster right in your own home, using nothing but trash, water, air and … worms? If you think that sounds crazy, think again. Vermicomposting has become one of the latest must-do green projects for anyone looking to reduce waste and promote healthy living, and is considered a viable indoor composting option. According to Norman Q. Arancon and Clive A. Edwards  in the Soil Ecology Laboratory at The Ohio State University “soil analyses after the vermicompost applications showed marked improvements in the overall physical and biochemical properties of the soil”.

So, what is vermicompost and how do you get it? Vermicompost, also known as worm castings, is the end-product of the breakdown of organic matter by certain types of earthworms. Most vermicomposters use red-wigglers or red worms (Eisenia fetida) in their compost bins. Red wigglers are surface dwelling worms that live in rich organic matter as opposed to dirt. These worms need to be introduced, they aren’t normally found around homes or in gardens.

To get started vermicomposting you need worms, bedding, waste material and a bin to put it all in.  Most home vermicomposters use medium sized Rubbermaid type tubs that can be found at most hardware and large box stores like Wal-Mart, Lowes or Target. Once you have your bin you need some sort of bedding for the worms to live in; shredded newspaper, cardboard or even aged straw. The bedding needs to be damp, similar in wetness to a rung out sponge. You’ll want to fill your bin about halfway up with the bedding materials.

Next you need waste materials, the “food” for the worms. This includes waste vegetables and fruits, aged animal manure, coffee grounds, breads (starchy items), tea bags, and ground up egg shells. You’ll want to avoid meat and dairy products, oil products, chemicals, and human or pet waste. You want to make a thin layer of these items on the top of the bedding, and maintain that layer as needed. Most people keep a container in their kitchen for the waste intended for the worms, and feed them with it every couple of days or as needed.

Finally, you need the worms! Again, you’ll want to make sure you get red-wigglers, not the worms you might find out in your garden. Red-wigglers can be ordered, there are many companies that now sell them just for vermicomposting purposes. Check out SLO County Worm Farm or Red Worm Composting to order and for more information.

So, what now? After about 3-6 months, depending on the size of your bin and the number of worms you have, you’ll find that all the bedding and scraps have been turned into a dark brown earthlike material. This is your vermicompost, a nutrient rich additive for your soil and garden! The easiest, but most time consuming, way to harvest your castings is by piling the compost under a lamp or in the sunlight and slowly removing the outside layers of castings. Red-wigglers are sensitive to light and will go to the darkest area they can find, so as you strip away layers they will dig deeper into the pile. Soon enough you’ll be left with a pile of worm-free castings and another pile of worms. You can use these worms to repopulate your bin and start all over again!

Now that you have your worm castings, you can use them as you would any other organic fertilizer. Many people top-dress houseplants, so each time they water, the plant gets a dose of nutrients straight to the roots. It can also be used for transplanting plants; add a small scoop to the bottom of the hole before you put the plant there. Another very useful option is to brew some “compost tea” with it. Imagine a giant tea bag with worm castings in it, soaking in a bucket of water. You can use a piece of pantyhose or even a dishtowel tied up with the worm castings. After a few days, the water will be filled with the nutrients from castings and can be poured on plants to give them a boost.

Worm castings contain much needed nutrients, including nitrogen and phosphorous, and some studies show that plants can have a 137% increase in growth when worm castings or vermicompost tea is used. So, add this fun and even educational project to your list of green living options today!


SLO County Worm Farm. Web. 08 Aug. 2011.

Red Worm Composting. Web. 08 Aug. 2011.

Munroe, Glenn. “Manual of On-Farm Vermicomposting and Vermiculture.” Organic Agriculture Centre of Canada. Web. 8 Aug. 2011. <>

About the author

Sarah Worley

Sarah is a wife and mother living on the central coast of California. She runs a small CSA where they have a myriad of farm animals including chickens, goats, pigs and bees. They grow a large percentage of their fruit, vegetables and meat and strive for sustainability and self-sufficiency on their 2 acre patch of heaven.

1 Comment

  • Let us continue to grow and maintain our beautiful organic gardens and sustainable energy systems and agriculture.