Beneficial Insects
Garden Pests
Composting
Fertilize & Mulch
Garden Plans
Quick Tips
Specialty Gardens

Gardening — Vermiculture Composting

What is Vermiculture?

Graphic showing the vermiculture process. 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. This method is simple, effective, convenient, and noiseless. It saves water, energy, landfills, and helps rebuild the soil. The worm’s ability to convert organic waste into nutrient-rich material reduces the need for synthetic fertilizers.

We violate nature’s ability to complete the life cycle process when we send food down the garbage disposal, or bury it in a landfill. We deplete the soil and deprive nature from rehabilitating itself when we bypass this natural life cycle recycling process.

Does Vermiculture Benefit the Soil?

Vermicompost improves soil structure, texture, and aeration as well as increasing its water-holding capacity. Your plants will grow stronger and have deeper root systems for better drought tolerance and disease resistance.

Worms are necessary to help produce top soil. Worms help the environment by decomposing organic material (food and yard waste) turning it into a natural rich organic soil amendment. The end result is called vermicompost, worm poop, or worm castings. Vermicompost provides a tremendous source of nutrients for plants that dramatically improves the texture and fertility of soil. This replaces valuable nutrients taken out of the soil when fruit and vegetables are harvested.

Worms are necessary to help produce top soil. Worms help the environment by decomposing organic material (food and yard waste) turning it into a natural rich organic soil amendment. The end result is called vermicompost, worm poop, or worm castings. Vermicompost provides a tremendous source of nutrients for plants that dramatically improves the texture and fertility of soil. This replaces valuable nutrients taken out of the soil when fruit and vegetables are harvested.

Vermicomposting adds beneficial organisms to the soil. These microorganisms and soil fauna help break down organic materials and convert nutrients into a more available food form for plants.

Results comparing plants with and without using vermiculture. Like composting, vermiculture composting is nature’s way of completing the recycling loop. Being born, living, dying, and being reborn again. Adding compost to soil aids in erosion control, promotes soil fertility, and stimulates healthy root development in plants.

What Do You Feed Worms?

 Food scraps from the kitchen like fruit and vegetable trimmings, lettuce leaves, carrot tops, ground egg shells, orange peelings, banana peelings.
 Yard trimmings, grass clippings, leaves, and mulch are great for vermiculture.
 Anything but meat and dairy products.

Where Do You Keep Worms?

Red Worms or (Eisenia fetida) are the best type of worm for eating food waste. These worms are surface worms and stay in the top 18 inches of the soil. It is usually best to keep them in a closed container so you can keep the process going. Every three months the worms should be harvested separated from the castings.

Making a Home for Your Worms

Hands holding worms and worm compost. Obtain a worm bin. The worm bin is basically the home for the worms, and the place where they digest the organic material you will give them. Worm bins can be purchased from many online vendors, or from your local gardening or farm supply store. If you don't want to buy a worm bin, you can also build one on your own. Use rubber storage totes, galvanized tubs, wood, or plastic.

Material: Rubber is cheap, easy to use and durable. Galvanized tubs are somewhat costly but will last forever. Wood will eventually be eaten, and plastic cracks easily, but either will do in a pinch. Some people prefer wooden compost worm bins because they may breathe better and absorb excess moisture, which can be hazardous to the worms. Just don't use chemically-treated wood, which may be dangerous to worms or leach harmful chemicals into your compost. 5 gallon (18.9 L) plastic buckets now for sale by most hardware stores can be used - especially if you live in an apartment. Clean the 5 gallon (18.9 L) buckets thoroughly with soap and let them sit for a day or so filled with clean water before using as a worm bin

Ventilation:  Your bin should be well-ventilated, with several 1/8 inch (3mm) holes 4 inches (100mm) from the bottom (otherwise the worms will stay at the bottom of the bin and you may drown your worms). For example, you can build a worm bin out of a large plastic tub with several dozen small holes drilled out on the bottom and sides. Untreated wooden bins are naturally ventilated because of structure of wood.

Size:  The larger you make the container, the more worms it can sustain. Estimate 1 pound (0.45kg) of worms for every square foot of surface area. The maximum productive depth for your bin is 24 inches (61cm) deep because composting worms will not go further down than that.

Cover:  The bin should have a cover to prevent light from getting in and to prevent the compost from drying out. Choose or make a lid that can be removed if your compost is too wet. Use a canvas tarp, doubled over and bungee-corded on, or kept in place with wood. Burlap sacks also work well, and can be watered directly. Place the worm bin in a cool area to protect it from excessive heat. If you're keeping your worm bin outside, consider placing it in the shade, under a tree, in the garage or shed, or along the side of the house.

Try keeping the outdoor temperature in the bin between 30 and 70 degrees Fahrenheit, along with at least 4 inches of moist bedding in the bin. This should be an ideal home for your compost-zapping worms.

Building Your Ecosystem

Getting started with vermiculture. Prepare the bedding for your worms. The bedding is the natural habitat of the worm that you're trying to replicate in your compost bin. Fill your bin with thin strips of unbleached corrugated cardboard or shredded newspaper, straw, dry grass, or some similar material. This provides a source of fiber to the worms and keeps the bin wellventilated. Sprinkle a handful of dirt on top, and thoroughly moisten. Allow the water to soak in for at least a day before adding worms.

Over time, the bedding will be turned into nutrient-rich compost material by the worms. When you harvest the composted soil, you'll have to introduce new bedding into the worm bin again. Canadian peat moss, sawdust, (rinsed) horse manure, and coconut pith fiber are also great for composting.

Avoid putting pine, redwood, bay or eucalyptus leaves into your bedding. Most brown leaves are acceptable in vermicompost, but eucalyptus leaves in particular act as an insecticide and will kill off your worms

Choose which worms you want. There are several varieties of worms that that are bred and sold commercially for vermicomposting; just digging up earthworms from your backyard is not recommended. The Internet or local gardening club is your best bet for finding a worm vendor near you. A pound of worms is all that is recommended. The worms most often used, Eisenia fetida (Red Wigglers), are about 4 inches long, mainly red along the body with a yellow tail. These worms have a healthy appetite and reproduce quickly. They are capable of eating more than half their own weight in food every day.

Another variety to consider are Eisenia hortensis, known as "European night crawlers." They do not reproduce quite as fast as the red wigglers, but grow to be larger, eat coarser paper and cardboard better, and seem to be heartier. They are also better fishing worms when they do reach full size.

However, as with any non-native species, it is important NOT to allow European night crawlers to reach the wild. Their voracious appetites and reproductive rates (especially among the red wigglers) have been known to upset the delicate balance of the hardwood forests by consuming the leaf litter too quickly. This event leaves too little leaf litter to slowly incubate the hard shelled nuts and leads to excessive erosion as well as negatively affecting the pH of the soil. So, do your best to keep them confined!

Maintaining and Harvesting Your Compost

Feed your worms digestible amounts regularly. The bedding of your compost bin is a great start, but the worms need a steady diet of food scraps in order to stay healthy and produce compost. Feed your worms at least once a week in the beginning, but only a small amount. As the worms reproduce and grow in numbers, try to feed them at least a quart of food scraps per square foot of surface area each week.

Worms eat fruit and vegetable scraps; bread and other grains; tea leaves; coffee grounds; and egg shells. Worms eat basically what humans eat, except they are much less picky!

If you can process your scraps before you introduce them into the compost bin, you'll find that your worms will eat them quicker. Worms go through smaller-sized food more quickly than they can larger-sized or whole food. In this respect, they are also like humans.

Mix the scraps into the bedding when you feed the worms. This will cut down on fruit flies and will give the worms more opportunities to eat. Don't just leave the scraps on top of the compost heap.

Maintain Your Bin

Keeping your bin elevated off the ground, using bricks, cinder blocks, or whatever is convenient will help speed composting and keep your worms happy. Worms are capable of escaping almost anything, but if you keep your worms fed and properly damp, they should not try to escape. A light in the same area will ensure your worms stay put.

Sprinkle the surface with water every other day. You want your bedding to have the dampness of a wrung-out sponge.

Add more cardboard, shredded newspaper, hay, or other fibrous material once a month, or as needed. Your worms will reduce everything in your bin quickly. You will start with a full bin of compost or paper/cardboard, and soon it will be half full. This is the time to add fibrous material.