Spring is upon us. With the snow off the ground (for now at least), and little new growth to obscure our view of the soil, it is easy to see the early stirrings of earthworm activity. Earthworm castings, neat piles of worm poop deposited on the surface as the worms busy themselves with their soil-work, are already accumulating on the lawns and parkways. Although nothing seems as natural or as necessary as this silent toiling, earthworms are, in fact, not native to the Chicago area.
As crazy as it may sound, nearly every earthworm you’ve seen in Chicago is an import! Native or not, their presence in gardens is often welcome as they increase soil fertility, making for bigger plants. However, in natural areas, where plant and animal communities have developed over thousands of years on worm-less soils, earthworm presence can be disruptive to these communities. Worms may be excellent companions in our vegetable plots, but are not so welcome in our natural areas.