A website from UGA Cooperative Extension

by Sabine Savoie, Fulton County Master Gardener Extension Volunteer

This article is part of Garden Buzz, a series from Appen Media and the North Fulton Master Gardeners, where rotating columnists explore horticulture topics like herbs, insects, and wildlife conservation. Find all Garden Buzz articles here.

Yucky! Slimy! Gross! These are the adjectives used to describe the unsung hero of the garden, the lowly worm. Yet worms do so much, from building healthy soil to helping us lead more sustainable lifestyles.

Using their grinding mouthparts, worms break down fallen leaves, twigs and even tiny pebbles. They create small tunnels in the ground, allowing air and water to get to the roots of plants. As worms tunnel through the ground, they loosen the soil, enabling the plant roots to spread more readily and take up nutrients from the soil. This is especially important when trying to grow plants in our famously hard, red clay. Best of all, they poop. It is this poop, also called worm castings (if you are in polite company), that is some of the best fertilizer around. No chemicals needed!

Pictured above is a worm bin, worms in bedding, a sieve, kitchen scraps, and garden gold (worm castings). Image by the author.

How can I get some of this fertilizer you may ask? Well, you can buy it, or you can grow your own with little time and effort. In so doing, you are also helping to lower your carbon footprint.

To get started, you need a large plastic tote (18” wide by 22” long by 14” deep) with a lid, some shredded newspaper, newsprint, or coconut coir and a bunch of red wiggler worms. The earthworms found in the garden will not survive in the tote, but the red wigglers will do just fine. Red wigglers can be purchased online.

About 9 inches from the bottom of the tote, drill holes all around the top of the tote and all over the lid. The holes should be about the diameter of a Sharpie pen. This allows the worms to breathe and the worm bin to ventilate. Don’t worry, the worms will not crawl out of the holes. They don’t like light. My bin is kept in a dark spot in the basement. The bin doesn’t get too cold in the winter and not too warm in the summer.

Shred your newspaper or newsprint. Avoid using colored newspaper, such as comics or ads. The finer the shred, the better. Moisten the shredded paper or coconut coir. You are trying to create the consistency of good garden soil. This will be used for the worm bedding. Do not soak your bedding material. The worms will drown. Make enough bedding so that it is about 4 inches deep once placed into the bin. Keep in mind that, as food scraps are added and decompose, they will also keep the bedding moist. If your bin is too wet, add more paper or torn up cardboard egg cartons. This will help soak up excessive moisture. Your worm bin should not smell bad. It may smell earthy, or if you are adding lots of coffee grounds, it may even smell a little like coffee, but there should never be a foul odor. A foul odor is usually an indicator of too much moisture. If your worm bedding is too dry, spritz it with a spray bottle.

Add the worms to your bin and give them something good to eat. They like fruit, such as banana peels, apple cores, strawberry hulls, melon rinds and coffee grounds, including the coffee filter. They like most any vegetable scraps. The food scraps to avoid are those high in acid, such as citrus, onions, garlic and tomatoes. DO NOT add meat, fats or seasonings. Chop up the food scraps. The finer the food scraps, the finer your worm castings will be. I like to add eggshells. The worms like to nestle up inside the shells. Occasionally I’ll finely grind eggshells into a powder and add it into the worm bin. The eggshell grounds help to keep the worms’ gizzards sharp. I feed my worms once a week and check up on them to see if they are thriving.

About every three to four months, it will be time to harvest the worm castings. To prepare for the harvesting, stop feeding the worms about a month in advance. This allows the worms to eat up any of the remaining food scraps. There are several methods of harvesting which can be found online. I like using a simple mesh sieve. The openings are large enough for the castings to fall through but not big enough for the worms or remaining eggshells to fall through. I prepare a fresh batch of bedding and transfer the worms and remaining eggshells to the fresh bedding as they are sifted out from the castings. The castings are bagged up and ready to be applied to the plants in your garden.

The plants will grow and get harvested. Parts of the plants will become kitchen scraps. The kitchen scraps will become worm food, and the cycle starts all over again. Not a thing in this process makes it into a landfill. Now that is sustainability. It’s a beautiful thing!

Happy gardening!


Learn More


This week’s “Garden Buzz” guest columnist is Sabine Savoie, a Master Gardener and Sandy Springs resident. Her favorite plants are natives and perennials. Sabine’s gardening goal is to make her property a place where wildlife and people can coexist in an urban setting. She delights in seeing fireflies in the summer and the return of Monarch butterflies in the fall.