Nature's Secret Gardener: All About Earthworms

Earthworms live within the soil, burrowing both vertically and horizontally at different depths. During these when they are burrowing, earthworms are actually eating the soil and extracting waste that helps improve the quality of the soil. The burrows created by earthworms are also beneficial because they loosen and aerate the soil, making it looser and helping the dirt absorb water more readily. As earthworms perform their gardening tasks within the soil, the gardener can expect beautiful growing results in flowers and vegetables.

Earthworm Anatomy

Earthworms are usually a reddish-brown color. The typical earthworm is a few inches long, although some earthworm species can grow to be significantly longer than this. Earthworm bodies are segmented, with each tiny segment having small bristles that enable them to move through the soil. A typical earthworm body contains between 100 and 150 segments. The earthworm segments provide both strength and flexibility. The digestive system of earthworms has multiple regions for processing the soil they eat. As the soil moves through the mouth and the pharynx, it progresses to the esophagus and then to the crop. From the crop, food moves to the gizzard for grinding. After the gizzard, the intestines continue the digestive process before the waste products are released back into the soil.

Overview of Earthworms – The United States Botanic Garden provides detailed information about earthworms, including diagrams about how they live beneath the surface of the soil.
Earthworms Help the Environment – Explore earthworm anatomy with pictures and simple descriptions about the anatomical systems of these creatures.
Earthworm Information – The Colorado State University shares information about three different types of earthworms, the anecic, endogeic, and epigeic.
More About Worms – Cornell University shares details about earthworms, such as the fact that earthworms eat their individual weight in soil every day.
Learn about Earthworms – The University of Florida teaches readers about earthworms with pictures and simple descriptions of these creatures.

Soil Benefits from Earthworms

The waste products excreted into the soil by earthworms are called worm castings. These worm castings are natural fertilizers that have a direct impact on the overall quality of the soil, improving the mineral level. Soil aeration is also extremely beneficial for overall soil quality. As worm tunneling loosens soil, not only does it absorb moisture more easily, but plant roots also grow more effectively and easily through the soil.

The Living Soil Earthworms – The United States Department of Agriculture provides information about earthworms, including how they benefit garden soil.
Did You Know…Earthworms (PDF) – Soil with earthworms present in it is richer in nitrogen, phosphorus, magnesium, carbon, calcium, and potassium.
Using Earthworms to Improve Soil Health and Suppress Diseases (PDF) – The Connecticut Agricultural Experiment Station provides education about how to use earthworms to improve soil composition.
Benefits of Earthworms – Explore the many benefits of earthworms in soil, including the aeration and enrichment of dirt to make it better for plant growth.

Earthworm Composting

With a bin, some earthworms, bedding, and food for the worms, you can easily produce your own compost to use for your vegetables and flowers. Even a standard plastic storage container can serve as a composting bin as long as it has a snug lid. Bedding consists of compost, shredded newspapers, cardboard, leaves, or sawdust. After adding the worms to the bin, provide them with regular amounts of food such as vegetable scraps and coffee grounds. You will also need to provide the correct temperature for the worms in the bin, ideally between 59 and 77 degrees Fahrenheit. Within three to six months, you should have a supply of compost.

Home Composting with Earthworms (PDF) – Explore the process of composting with earthworms to learn how you can make your own compost for gardening.

Invasive and Exotic Earthworms

Although many earthworms that have lived in the soils of North America are technically exotic, these typical earthworms have not caused harm to ecosystems; however, additional types of exotic earthworms, such as an Asian earthworm, are becoming a threat to soil. Some of these worms exhibit unusual behavior, such as jumping. Some exotic worms also have a high metabolism, which enables them to live in areas densely populated with other worms. A forest populated by an invasive species of earthworm may exhibit marked decrease in understory growth due to changes in soil composition.

Exotic Earthworm Information – The Natural Resources Research Institute explains potential risks with recent invasions of exotic earthworms. Changes in soil structure seem to be resulting in declining plant growth.
Invasive Earthworms in the Northeastern USA and the Horticulture Industry (PDF) – The negative impact of invasive earthworms is changing how forests in New England grow due to shifts in soil composition.