Types of Composting Worms

How many species of worms exist on our planet?  Go ahead, take a guess.  Nope.  Not even close.  There are approximately 7000 species of worms and most are not well suited to composting.

So what are all those worm species doing all day?  Most spend their day plodding through the various layers of our soil, eating, crawling, investigating.  As a whole, worms have a tremendous impact on our soil structure and health.

Not all worms are equal

The two types of worms that most gardeners want to see in their soil are burrowing and feeding worms.

Burrowing worms aerate the soil as they construct horizontal pathways underground.  This allows nutrients and water to move through the strata of the soil more easily benefiting the plants as a result.  Though burrowing worms, also known as endogeic worms, will feed on organic material they tend to live below the surface.

Feeding worms tend to be surface dwellers and dine exclusively on decaying organic material like leaves and plant material.  These types of worms are called epigeic worms and they are not very skilled at burrowing.  They thrive in very loose organic-rich soils like those in the worm composting bin.  They could thrive in your garden if it has a sufficient top layer of loose organic material.

Though both types of worms are welcome in the garden, it’s the composting worms that we’re interested in for this article.  They are the workhorses that turn otherwise wasted garden and kitchen scraps into black gold, an asset for any garden.

Which worm species is king of the composting worms?

There are several worms species in the epigeic family that are suitable for the composting process, including red wigglers, redworms, European nightcrawlers, African nightcrawlers, and the Malaysian Blue Worm.  But the true champ is the red wiggler, a runaway favorite of all composting worms with gardeners.  They reproduce at a fast pace, are content to live in close quarters with their cousins, eat like teenage boys, and consume a variety of organic materials.  Plus, they are most suited to our climate here in North America.

These little composting machines are built to do exactly what they do.  In an established worm bin, red wigglers will eat as much as half their weight each day.  And doubling their population in 90 days, you can imagine just how quickly they could consume the food scraps from the typical American kitchen.

You can learn more about the anatomy of the red wiggler and use this nifty diagram in your class.