Worm Composting

Red Wiggler (Eisenia fetida)
Red Wiggler (Eisenia fetida)

Download this page as a PDF, for printing

Where can I get worms?

In Buffalo, Caesandra Seawell and Kevin Hayes of the U-Pick Worm Farm are selling worms to local worm composters.

The current price of worms at our U-Pick Worm Farm is 10 cents per worm.

If you’d like to buy some worms from us, just email caesandra@caesandra.com.

How does worm composting work?

Simply put, you make a nice home for red wriggler worms with some shredded paper bedding, add your kitchen garbage, and the worms, together with other organisms, eat your garbage and produce an excellent compost for your garden or houseplants. They also reproduce prolifically, so you only need to buy your worms once.

What are the benefits of worm composting?

Worm composting is a handy, convenient way to compost your kitchen and garden waste. You can compost with worms if you don’t have a garden or yard because of smaller space needs. Worms can decompose organic matter without as much physical effort on your part as traditional composting in bins or compost piles.

Benefits to Soil

  • Improves its physical structure & water-holding capacity
  • Enriches it with micro-organisms
  • Microbial activity in worm castings is 10 to 20 times higher than in the soil and organic matter that the worm ingests
  • Attracts deep-burrowing earthworms already present in the soil

Benefits to Plant growth

  • Enhances germination, plant growth, and crop yield
  • Improves root growth and structure

What kind of worms should I use?

The best worms for composting are the species Eisenia fetida, commonly known as redworms or red wigglers. These worms are famous garbage eaters. They are NOT what’s usually called earthworms, as they don’t live in the soil, but rather are attracted to and live in decomposing matter.

Where will my worms live?

To be happy and healthy, worms must have:

  • Stable temperatures
  • Appropriate moisture
  • Food
  • An absence of light

So you’ll need a box or bin of some kind, bedding such as shredded or torn paper, and a lid to keep the light out. As for food, most households produce an abundance of “waste” that worms love to eat. Usually, having too much worm food is a more common occurrence than not having enough!

Worm bins may be made of new or, better yet, used plastic, wood, Styrofoam, or metal containers. Bins need holes or mesh for aeration, and a spout, holes or a lattice of sticks in the bottom for excess liquid to drain into for collection. Wooden bins will eventually decay and need to be replaced. Worms are very sensitive to chemicals or other pollutants, so make sure you’re using a clean, non-contaminated container. Plastic storage bins are a very common and reasonably low cost container.

Worms used in composting systems prefer temperatures of 55 to 70 degrees F. If a worm bin is kept outside, it should be placed in a sheltered position away from direct sunlight and insulated against frost in winter. Some backyard composters build a bottomless worm bin that sits on top of or is built into the ground. If the worms can escape adverse conditions by burrowing down, their survival and success increases greatly.

We don’t recommend keeping your worms outside in the winter, as freezing temperatures will kill them. Sometimes their cocoons will survive and hatch in the Spring, but it’s better if the worms can live inside, even if the temperature falls below 55 degrees.

Most of the time, cool temperatures just slow their activity but doesn’t kill them; when it warms up, they get right back to work, eating and reproducing.

Earthworm Anatomy (Portuguese)
Earthworm Anatomy (Portuguese)

How do worms produce compost?

Worm compost is the byproduct of the worm’s natural life cycle of eating garbage and excreting liquid and solid waste. Worms, bacteria, insects and fungi are the major catalysts for decomposing food waste in healthy soil; a worm composting bin is just the creation of an ideal environment for those organisms to do their thing.

What will my worms eat?

Home worm composters usually feed their worms kitchen and garden waste. This includes all fruits and vegetables (including citrus and other “high acid” foods); vegetable and fruit peels and ends; coffee grounds and filters; tea bags; plate scrapings, moldy bread; leaves and grass clippings (not sprayed with pesticides). Bedding such as shredded paper also breaks down completely and becomes part of the end result, the worm compost.

There are few food wastes vermicomposting can’t compost, although meat waste and dairy products are likely to putrefy, and in outdoor bins can attract vermin. Small animal bones and eggshells will often not decompose completely, but will eventually break down when added to garden soil. Green waste should be added in moderation to avoid heating the bin by way of traditional non-worm composting.

You don’t need to cut or shred your garbage, though that will speed decomposition. Most of us let the worms and their decomposing friends do the work instead.

What about problems?

ODORS: When closed, a well-maintained bin is odorless; when opened, it should have a rich earthy smell like a forest floor. Bins must be oxygenated – if decomposition becomes anaerobic from excess worm food added to the bin in wet conditions or layers of food waste have become too deep, the bin will begin to smell like ammonia. To restore healthy conditions and prevent the worms from dying, the smelly, excess waste water must be removed and the bin returned to a normal moisture level. To do this, first reduce your addition of food scraps with a high moisture content and second, add fresh, dry bedding such as shredded paper to your bin, mixing it in well.

PESTS: Pests such as rodents and flies are attracted by certain materials and odors, usually from large amounts of kitchen waste, particularly meat. By eliminating the use of meat or dairy products in your worm bin you decrease the possibility of pests.

FRUIT FLIES: In warm weather, fruit flies will breed in the bins if fruit and vegetable waste is not thoroughly covered with bedding. This problem can be avoided by maintaining the proper temperature, to allow worms to continue eating the waste and allow the beneficial microbes to continue blooming. Sometimes covering the entire bin with a towel or sheet will cut down on fruit flies.

Where can I learn more?

A well known book all about worm composting is “Worms Eat My Garbage”, by Mary Appelhof (ISBN 978-0977804511). A visit to your local library or a little web browsing will provide an abundance of information to help you succeed.

March 2014