The Homeowners Column

The Homeowners Column

Earthworms - Where being slimy isn't all bad

Photo of Sandra Mason

Sandra Mason
State Master Gardener Coordinator

Rain may be a welcome event for gardeners but I think the earthworms don't share our excitement. I assume their wanderings across streets and parking lots have more to do with their flooded homes than getting to the other side. If you are slimy and live in the dark a parking lot is not the place to be once the sun comes out. We humans just don't have an affinity for slime once we get past the age of eight. However as gardeners and agriculturists we shouldn't underestimate the power of a bunch of earthworms.

According to University of Illinois, a population of 500,000 earthworms per acre could:

  • Produce a drainage system equal to about 2,000 feet of 6-inch drainage tile.
  • Produce 50 tons of castings (a fancy word for worm poop) - an equivalent of roughly 1/3 inch surface applied manure per acre. That's like lining up 100,000 one pound coffee cans filled with castings.
  • Add 2 pounds of nitrate nitrogen, 15 pounds of phosphorus, 36 pounds of potash, 45 pounds of magnesium and 250 pounds of calcium to each acre of soil annually.

Most people see worms as fish bait or as carcasses to step over after a hard rain. Earthworms get no respect for all the work they do. In one acre of land, there can be more than a million earthworms improving our soils for growing healthy plants.

Worms help to increase the amount of air and water that gets into the soil. Their tunnels create a network of "pipes" so rainwater and air can infiltrate soil. Worms help to loosen the soil without tilling. Earthworms are like free farm help. They help to "turn" the soil—bringing down organic matter from the top and mixing it with the soil below. Worms tunnel deeply in the soil and bring subsoil closer to the surface mixing it with the topsoil. Earthworm slime contains nitrogen, an important nutrient for plants. The sticky slime also helps to hold clusters of soil particles together for good soil structure.

Worms leave behind (literally) castings that are valuable as a fertilizer. Worms also break down organic matter, like leaves and grass into nutrients that plants can use. Worms can eat their weight each day. And yet they stay so slender.

Having worms in your garden is a good indicator of healthy soil. Worms won't survive in really lousy soils. Worms live where there is food, moisture, oxygen and a favorable temperature. If they don't have these things, they go somewhere else.

To get earthworms in your garden it is pretty much a "Build it and they will come" philosophy.

Here are some simple tasks to encourage worms in your garden:

  • Add organic matter regularly by loosening soil rather than turning it over.
  • Use mulch especially shredded leaves; keep soil covered all year either with mulch, compost or cover crops.
  • Spread compost over gardens in the fall.
  • Till only when necessary.
  • Use little or no insecticides on soil.

Some gardeners choose to farm worms by making a worm-composting bin. Worm composting, vermicomposting, is a good way to get rid of your kitchen vegetable scraps and a source of compost for garden plants. The worms used in worm composting are not the same worms we find as earthworms. These are the fish bait kind called red wrigglers. Just stop by the bait store. I'm sure the worms would appreciate being rescued from their watery doom.

A distance learning presentation on the basics of vermicomposting will be held on Thursday September 9 at 1:30PM and repeated at 6:30PM at the UI Extension office at 801 North Country Fair Drive Champaign. To register call 217-333-7672 or register online Check out for some really fun facts about worms.

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