If compost worms are the recyclers of the garden ecosystem, the worms living in the soil itself are the engineers. These worms spend their lives moving through the soil, quietly reshaping the structure beneath our feet.

Gardeners have long noticed that where worms are plentiful, plants tend to thrive. The reason is simple: worms improve soil structure, aerate the ground, and help water move more easily through the soil. In many ways, they function as nature’s plow.

Two common groups of worms responsible for this work are nightcrawlers and field worms.

Nightcrawlers – The Deep Tunnel Builders

Nightcrawlers are among the most familiar worms gardeners encounter. These larger worms create deep vertical burrows that can extend several feet into the soil.

Unlike compost worms, nightcrawlers come to the surface mostly at night to gather food. They pull leaves, plant debris, and other organic materials down into their burrows where...