Making A Worm Bin

June 12, 2013

Making A Worm Bin (Vermicomposting – Indoor Composting with Worms)

By Dawn Pettinelli, Associate Extension Educator, PSLA. (Written 2014, updated 2025)

making a worm bin, dirt in a plastic container

Looking for a low-tech way to recycle kitchen scraps while at the same time creating a great soil amendment, right in your own home? If so, vermicomposting, or in layman’s terms, composting with worms might be just the solution you are looking for. The basic premise of vermicomposting is that worms live in a container of moistened, shredded paper bedding into which food wastes are placed. The worms consume both the bedding and the kitchen scraps, and produce nutrient-rich castings that are added to gardens or planting mixes. A well-maintained worm bin should not smell and can recycle at least one pound of food waste for every pound of worms per week.

There are several ready-made worm bins on the market. Some consist of stacking trays with a liquid collection pan at the bottom while others are more simple plastic or wooden units. Most beginning worm farmers make their own bin out of a 5 to 10 gallon dark-colored, plastic storage bin with a lid. Do not purchase clear or translucent plastic bins as worms need a dark environment. As a general rule of thumb, each ¼ lbs. of worms requires about one square foot of space so the size of the container depends on how many worms will be acquired.

Drill

1/8 to ¼ holes in the top, sides and bottom for oxygen to enter and for any liquid to drain. The number of holes varies although there are usually at least 2 rows of holes going around the sides and at least a dozen on the bottom and top. This smaller bin can be set inside a larger bin, other plastic container or foil roasting pan. The reason for this second container is to collect any excess liquid which might seep out if a lot of watery fruits and vegetables are feed to the worms and not enough absorbent bedding is added.

Newspaper is usually the bedding material of choice because of its widespread availability. Other bedding materials include shredded non-glossy office paper, non-corrugated cardboard (corrugated cardboard contains glues) or coconut coir that is sold in brick or pellet form and expands with water. Shred the newspaper or paper and soak in a bucket of water. Wring the paper out and place it in the worm bin fluffing it up somewhat and filling the bin 1/3 to ½ full of bedding. If mixing coconut coir in, soak that material first as well.

Worms do not have teeth. They digest their food in their gizzards and need grit to do this. Place a handful or two of very fine sand or soil into the bin and mix it into the moistened bedding. Because garden soil can harbor eggs of sowbugs, slugs, and undesirable (for composting) earthworm species, microwave each handful of soil for 90 seconds on high. Loosely cover the soil with plastic wrap or a paper towel before microwaving.

Learn more about what type of worms to use and how to feed and care for them; read the full article on our Soil Nutrient Analysis Laboratory website.

Questions? Contact:

UConn Soil Nutrient Analysis Laboratory
Department of Plant Science and Landscape Architecture
Phone: 860.486.4274
Email: soiltest@uconn.edu
Website: soiltesting.cahnr.uconn.edu