Worms

Worms, or wyrms as they were originally called, don’t technically exist. 

Wyrms referred a huge collection of tubular, limb-less critters back in the 1700’s. Of course, we all know what I mean when I say worm, right? Sure, we’ve all seen earthworms and red wigglers. But what about the 3-foot bristle worms, or the 22-foot African giant earthworm, or, are you ready for it? What about the 190-foot oceanic bootlace worm?!!? Crazy, right?

Earthworm and land planarian

Worm description

Well, clearly, we don’t ave any 190-foot worms in our gardens. What we do have is long, squishy bodies that are easier to describe by what they don’t have. Worms do not have legs, true limbs, scales, lungs, a brain, a true digestive system, or a circulatory system. They breathe through their skin, which needs to be moist at all times. Dehydrated worms become paralyzed.

You may be surprised to learn that many worms are not actually able to move themselves with muscles, the way we do. Instead, they move through the soil by the act of feeding. If you think about it, worms are one big food tube. Food is sucked into the mouth and passes through a pharynx, esophagus, crop, gizzard, and intestine, before being pushed out the other end. While worms do not have eyes, per se, some of them do have light sensing organs.

Types of garden worms

There are three different types of garden lifeforms that fall under the worm category:

• round worms (Nematoda)
• segmented worms (Annelida)
• flatworms (Platyhelminthes).

Nematodes are round worms. Earthworms are segmented. And flatworms, such as land planarians are, well, flat. The flatworms and roundworms are known as helminths and tend to be parasites of one form or another.

Worms improve soil

Worms are an important part of decomposition, whether it is happening underground or in your compost piles. Worms improve soil structure and soil health, making life a lot easier for your plants. As worm populations increase, drainage and porosity, or permeability also improve.

As worms eat, poop, and die, they create mucous-coated soil clumps, or aggregates, that have spaces for water, roots, and air to move through. These spaces, called macropores and micropores, are important factors in soil health. For example, in sandy soil, the spaces are very large and leaching can be a problem, while clay particles are very tiny and they hold tightly to water and nutrients, and often have compaction problems. Worms help offset those problems by helping to break down and decompose organic materials, improving soil structure, adding nutrients, and being part of the nitrogen cycle. Worms are an important part of the soil food web and they help keep plant and tree roots healthy.

Food for worms

Did you know that earthworms like coffee? It ends up that sprinkling coffee grounds around your yard is a good way to reduce compaction and a couple of fungal diseases. For some reason, worms tend to pull coffee ground deeper into the soil. We don’t know why. We do know that worms will eat dead plant material, insects, insect eggs, fungi, bacteria, dead animals, and even cardboard and paper.

While we may all end up as food for worms, more often than not, it is the worms who become the entree. Worms are commonly eaten by birds, amphibians, reptiles, and many mammals. Skunks, moles, shrews, raccoons, and rats will all gobble a worm, given the opportunity, as will centipedes, beetles,  and even other worms, such as land planarians.

Worms that are not worms 

Caterpillars, such as the impressively large Achemon sphinx moth, carpenterworm, and tomato hornworm larvae are commonly referred to as worms, as are tiny pink codling moth larvae, apple maggots, armyworms, cutworms, inchworms, naval orangeworms, and destructive green cabbageworm larvae, as are the microscopic larvae of dryberry mites. The larval form of click beetles are also called wireworms. And some people call grubs worms, too, but I have no idea why  Each of these not-worms is simply a developmental stage in a process of metamorphosis..

Help the worms in your yard

Worms do not have much of an arsenal when it comes to defense. The best way to help the worms in your yard is to create a healthy environment that meets their needs. If you build it, they will come. These tips will help you create a worm-friendly habitat in your yard:

• top dress beds with aged compost
• mulching
• plant green manures and cover crops
• keep soil moist but not soggy
• harvest crops by cutting mature plants off at the soil level, leaving the root system in place to slowly decompose
• use no-dig gardening methods 
• avoid slug baits that contain metaldehyde or carbaryl, and use iron phosphate instead

If you happen to use tower gardening or other containerized methods, you can always rescue a few worms stranded after a rain and add them to the pot. They and your plants will be better of! And if worms really fascinate you, you can also raise your own. This is called vermiculture.

Your yard may look quiet on the surface, but there is a lot going on underground. Even when given time to rest, or go fallow, there are still billions of processes happening in the soil beneath your feet, and worms are an important part of those processes.

Finally, there is a new threat in the world of soil organisms. This one is the Asian jumping worm. There will be more on that soon.