Worms and compost: the science of verminculture

Vermiculture is the process of using worms to decompose organic food waste, turning the waste into a nutrient-rich material capable of supplying necessary nutrients to help sustain plant growth. Simply put, it is nature’s own fertilizer and compost that is easy, simple, and effective.

Vermiculture is good for areas that do not put food waste into backyard compost piles to avoid attracting pests and possible odors. Worm compost bins are often described as the equivalent of an organic garbage disposal and offer the ideal solution.

Vermiculture can be used indoors or out, making it ideal for those living in an apartment or with little to no yard. Kids love it and school demonstrations on worm composting are always a fun and educational. Bins can be made with purchased plastic containers or built from wood or cinderblock, and constructed into an easily manageable, compact size.

There are two types of worms used in composting: redworms (the red wiggler) and brown-nose worms. Most people use the red wigglers as they are easily obtained, however they are different from your average night crawler. In order to create a healthy living environment for these industrious creatures, insure that your worms have what they need to thrive: a dark, moist environment, air to breathe, and food to eat. Worms double their population every 90 days, so your initial procurement of worms should be your last.

Indoor bins are normally made from 5 to 10 gallon plastic tubs with a snap-on lid. The length and width of the bin is more important than the depth. One square foot of surface area is needed for each pound of food waste to be added each week. Punch small 1/8-inch air holes around the sides of the bin about 1 inch apart. Don’t punch holes in the bottom as the liquids from the compost will drain out.

Outdoor bins can be made larger. Up to 4 feet wide by 3 feet long by 2 feet high. Keep the size manageable and remember that you will need to maintain it and cover it with a tight-fitting lid. You can recycle a barrel, trunk or old drawer, but stacking cinder blocks to the desired size is very easy to do.

Create bedding that fills the bin one-third to half full by soaking a large quantity of shredded newspapers, office paper, cardboard or even leaves. Don’t use anything with colored ink on it as the ink is toxic to the worms. Squeeze the water out the bedding so that it is no longer dripping and place it into your bin. Fluff it up to provide some air pockets. In the beginning, put in a small amount of soil, sand, leaves, sawdust or ground egg shells to provide the worms with grit which they need to break up up their food. Later on, the worm castings will provide any additional grit needed.

Place your worms into the middle of the bedding and cover them with dirt before closing the lid tightly. Worms need moderate temperatures to survive inside a container. A general rule of thumb is that if you are comfortable, they are comfortable – which usually means no hotter than 90 degrees or colder than 40 degrees. If you keep your bin in the garage, you may want to move the worms indoors in the winter if the area is not heated. Leave the worms alone for about a week so that they start eating the paper bedding before you begin adding your food scraps.

If you keep a plastic, lidded container under your sink or in your refrigerator, it is easy to collect your fruit and vegetable scraps, egg shells, coffee grounds and filters, and tea leaves and bags. Do not include meat, fish, cheese, oils or butters, or animal products. When adding your food scraps to the worm bin check it occasionally to insure the bedding is still wet. If it has started to dry, spray enough water onto it to thoroughly wet it.

At the end of each week, check to see if the food you’ve added has been eaten. Worms usually eat a pound of food per week for every square foot of surface space in their bin. The smaller the pieces of food waste are, the easier they will be for the worms to consume.

When most of the bedding has been eaten, harvest the worm castings and add new bedding. The easiest way to do this is to move everything over to one side of the bin. If there are any partially decomposed materials, pick them out and place them on the empty side, add a little food on top, and cover it with some fresh shredded paper.

Within a few weeks, the worms will finish whatever is left in the large pile and move over into the new bedding looking for more food. It is then easy to scoop out the finished compost. This material is nature’s fertilizer and can be used for anything from house plants to outdoor gardens. It is completely non-toxic and safe to use around kids and pets.

You may repeat the process, but remember your worm population will be constantly expanding. Consider releasing some worms into the wild (if temperature appropriate), or giving some to a friend who may want to begin their own worm farm.