Earthworms – your garden’s best friend

Wednesday, December 16, 2015

When we think about a garden’s soil teeming with life we generally think of tiny microbes that can only be viewed with a microscope.

But, there’s one major player that needs no magnification—earthworms. These industrious creatures burrow into the soil, improving its structure from the surface down, and producing castings that feed the earth and provide nutrients to plants.

Around the world there are about 7,000 species of earthworms. They live in most countries, except hot, arid deserts and very cold regions with permafrost.

No matter where you live, these squirmy wigglers bring huge benefits to the garden as they chew their way through the soil, forming small pathways for water to drain, oxygen to reach the roots and carbon dioxide to escape.

Earthworms that live close to the surface typically eat organic matter, like grass clippings and dead leaves. Worms living lower grind their way through the soil gleaning fungi, bacteria and other bits of organic matter trapped between the soil particles.

For the most part, earthworms ingest soil and the like at a rate up to 30 times their body weight each day. All the while, their up and down and sideways movements deposit nutrient-rich castings to plant roots, redistribute organic matter and allow water to penetrate. The lubricating mucus earthworms secrete helps bind soil particles, open pores and help prevent caking and erosion of the soil. They also help prevent runoff in rainy areas.

There are three main categories of earthworms found in the garden—shallow-dwelling, field worms and deep-dwelling night crawlers.

In my area, shallow-dwelling field worms are most common. They live in the top 6 to 12 inches of soil for about a year or two, creating horizontal tunnels and secreting their castings wherever they travel.

Field worms are primarily active in the spring, when the soil is moist and the temperatures are moderate. Hot, dry soil sends them deeper into a resting stage, but they perk up in the fall with early rains or irrigation, then return to a resting stage to wait out a cold winter.

Deep-dwelling night crawlers are rare in my area, but more common in the east and mid-west, where they dig vertically into the soil creating tunnels several feet deep. When they slink to the surface to gather food and slide down to digest it, then back up again they deposit their castings and plant residue on top of the soil.

Like field worms, night crawlers burrow deep into the soil during hot spells, then perk up with spring and winter rains. Some studies claim they can travel up to 60 plus feet in one night. Night crawlers can live 3 to 4 years, if they’re not collected for fishing bait.

Another category of earthworm is the red worm, those debris loving wrigglers that thrive above the soil in leaf litter and compost bins or worm bins.

For most of the year in my area (the Central CA Coast) earthworms are dormant, curled up in little balls just below the soil’s surface encased in a protective covering lined with mucus.

No matter which type of earthworm you have in your area they are a powerhouse worker in the garden and should be cultivated, encouraged and protected, so they can produce maximum benefits for your vegetables and flowers.

Leave a Reply