often sold commercially as fishing worms.
Earthworms are all muscle, so they are mostly protein. They grind up soil, digest dead organic matter, and produce perfect manure for potting soil. They are unique in having glands that produce calcium to sweeten the soil. They like sweet soil, and they make it sweeter. Almost all plants grow best in sweet soil, the exceptions being the acid-loving plants like hydrangeas and blueberries.
When earthworms die, they add nitrogen to the soil. While they live, they add it in the form of liquid and solid waste.
Thoroughly modern, they are bisexual, each one have a male and a female gland. They line up like elevens and later an earthworm egg rolls off the outside. Each egg contains many babies. The mature worms are quite fragile and die easily from heat, sunlight, or a lack of water. The eggs survive almost anything, so the spread of compost means the growth of the earthworm population.
The digging and tunneling of an earthworm is very important to the garden. Earthworms pull organic material down into the soil, digest it, and deposit their manure (called castings) in the soil or on top. Their castings are perfect for plant growth, so this must have been planned by the Creator. If not, the plants must be grateful for the cleverness of their vermicular friends. Who better to live near the roots than a guy who aerates the soil, builds tunnels for rainwater to seep down, fertilizes the soil, and leaves dozens of children to continue the work?
Many people make fun of the lowly work of the earthworm, but up to a million worms might be at work in a fertile acre of ground. They collectively move about a ton of soil a day, without damaging the growing plants. They deposit an enormous quantity of castings per year.
Charles Darwin studied earthworms for 40 years and gave them credit for burying ancient monuments by adding a little soil each year to the top. Sadly, he missed entirely the agricultural value of the earthworm.
One of the prevailing myths of gardening holds that sand added to clay soil will make the clay easier to work. Ha. The best addition to clay soil is compost, because compost will multiply the earthworm population and mix the humus material with the clay.
Clay soil is very high in minerals and ion exchange, so the addition of compost will make it the ideal medium for almost all plants, thanks to the earthworm.
Sandy soil will not hold water, stay in place, or support demanding plants like corn and pumpkins. Adding compost will mix humus in with the sand, thanks to earthworms. That will hold water in place, keep the soil from blowing away, and feed plants.
Finished composted will be dark, earthy smelling, and full of earth-worms. A compost pile will finish from the bottom up because of the soil creatures working their way up from the soil at the bottom.
