Soil Conditions Preferred by Earthworms

Earthworms don't like being out of soil.

Figuring out which comes first -- good soil or earthworms -- is like trying to solve the chicken-versus-the-egg puzzle. Earthworms prefer a loamy soil, but they also help create it. Give them organic matter to consume, as well as sufficient warmth and moisture, and they will make do.

Loam

Earthworms prefer loamy soil that is loose and rich in organic matter. They like plenty of leaves, manure, vegetable scraps, grass clippings, coffee grounds and other organic matter to drag down into their burrows. Like tiny plows, they spread it throughout the soil, breaking it into small bits through digestion and excretion.

Warmth and Moisture

The University of California at Davis notes that earthworms' needs are similar to those of plants. They need temperatures between 60 and 100 degrees Fahrenheit to thrive. Lack of moisture will cause them to shrivel, but too much rots roots and drives earthworms to the soil's surface where they may die.

pH Factor

Earthworms and plants don't like soil that is either extremely acidic (sour) or alkaline (sweet), conditions that can be gauged using a measurement called pH. In general, a pH measurement close to the neutral level of 7 is best.

References

• University of California, Davis: Earthworms and Soil Productivity
• Nature Watch: Worm Watch -- How Does an Earthworm Eat