Earthworms, also known as Lumbricus terrestris or angleworms, can grow up to 14 inches. They’re something that all of us in North America are familiar with. Most of us, at a young age, were introduced to the “slimy, gooey” things and learned to either love or loathe them.
Angleworms are generally liked by many in the United States with nicknames like:
- Fisherman’s friend
- Gardener’s buddy
- Earth diggers delight
Earthworms of various types have long been associated with healthy, productive soil.
What Do Worms Do for the Earth?
Earthworms offer many benefits to the gardener and are seen in healthy, organic soils. Many people believe that angleworms eat dirt. However, they eat the bacteria and fungi that grow on decomposing matter like a decaying plant. They give off “worm castings” which are a sort of manure and carbon dioxide filled with nutrients plants love.
There are more than 7,000 earthworm species divided into 23 families and over 700 genera. All of these earthworm populations have some aspects in common as they:
- Naturally till and aerate the soil.
- Accelerate the decomposition (composting) process.
- Help mix soils for more benefit.
- Are excellent “canaries” for monitoring a soil’s health.
Where are Earthworms Found?
Different parts of soil can contain different worm species. Each with different feeding strategies. Generally, these species are categorized into three main ecological groups. The groups are formed according to burrowing and feeding habits, and area of the soil.
All three groups are crucial to the structure of your garden soil and they include:
- Upper soil (Endogeic) species. This group of soil earthworms lives and moves along the upper soil strata. They feed mostly on soil and geophages but their burrows aren’t permanent. These angleworms fill their channels with cast material as they move along the soil.
- Surface soil and litter (Epigeic) species. This group can be found in or close to soil surface plant litter. The worms here are small in length and they adapt to different soil conditions on the surface. This means that they thrive regardless of temperature and moisture levels. However, they won’t survive in soils with low organic matter.
- Deep-burrowing (Anecic) species. These earthworms create long-lasting, quasi-permanent burrows. Their burrow systems can go as deep as several meters into the ground. The earthworms here consume surface litter that’s pulled through the burrows. It’s possible in some cases that they block the entrances to their burrows with cast or organic matter.
Are Worms a Sign of Good Soil?
Earthworms are great for the soil in your garden because they’re known to:
- Bury and shred decaying plants. Plant and crop residue are buried by worm castings deposited on the surface. Earthworms use these plants as food which they transport from the surface into their burrows.
- Mix and improve the soil. As the earthworms consume organic matter and mineral particles, earthworms poop out castings. Earthworms can move large amounts of soil from the lower strata to the surface. They can also carry organic matter down into deeper soil layers over periods of time.
A large amount of soil progressively passes through earthworms’ guts. It’s believed that they’ll turn over the top six inches of soil within two decades.
- Improve water-holding capacity. By breaking apart organic matter, earthworms loosen the soil and increase water-holding capacity.
- Loosen the soil and make it porous. Earthworms enhance porosity as they move through the soil. Some species make permanent tunnels deep into the soil. These tunnels can last long after the earthworm has died. This helps with soil drainage, especially during heavy rainfall.
Simultaneously, the tunnels minimize erosion due to surface water. The horizontal burrowing of other species increases overall drainage as they loosen the soil.
- Provide channels for root growth. The tunnels made by the burrowing earthworms have available nutrients from their castings. This makes it easier for roots to penetrate deep into the soil.
- Increase the soil’s microbial diversity. Earthworms get their nutrition from microorganisms like bacteria and fungi. However, there are more microorganisms present in worm castings than in organic matter.
As the matter goes through their intestines, it’s fragmented and inoculated with microorganisms. The increase in microbial activity aids the cycling of nutrients. It transforms them from organic matter to forms readily taken up by plants.
Red wigglers are commonly associated with compost, as they are:
- The most likely to appear in compost heaps.
- The ones used most often for vermicomposting (composting with worms).
- Faster than any other organism at the job.
An earthworm has been here!
How to Introduce Earthworms into Your Garden
You could purchase worms (they are sold by the pound in many garden stores) and just manually add them to the garden. This will work for the short term, but will not be very beneficial since worms are needed all season.
Encouraging earthworms naturally is the best way. It’s a case of “if you build it, they will come.” The better your soil for worm habitat, the more angleworms that will live in it. You don’t need to add earthworms, just encourage them to be there and they’ll show up on their own. They’ll improve your soil structure and make it easier for your plants to grow.
First, worms love organically-rich soil with a lot of nutrients and a neutral pH level. Start by doing basic tests on your soil (if you can) or just add a lot of organic matter to it. Till it in well and then add more on top, either as:
- Growing material (cover crops like clover or buckwheat).
- Or as mulch (clipped grass, leaves, straw, and other quality mulches work best).
Occasionally add light water and poke the soil with a compost fork (do not turn it).
After a few weeks, dig a cubic foot of soil and notice how many worms are present. There should be a considerable increase. By the end of the season, and thanks to the earthworms’ hard work you should have:
- Lots of worms per foot.
- Very rich, healthy soil with more organic matter.
Once the soil is healthy, just maintain it and the worms will stay, no matter what you’re growing in it.
As they thrive, they reproduce in a unique way as each is both male and female. According to the Earthworm Society of Britain:
“Earthworms are hermaphrodites, meaning they have both male and female reproductive organs.
When two earthworms are ready to mate they adopt a head-to-tail position, cover themselves in a layer of mucus, and exchange sperm. The saddle produces a mucous tube which detaches and moves forward along the body, collecting on the way the earthworm’s own eggs and the sperm received from its partner.
Fertilization occurs in the mucous tube which is shed from the front end of the earthworm. This dries in the soil to become an egg capsule, from which one or more young earthworms will eventually hatch. Many species can reproduce several times a year.”
How to Maintain a Healthy Environment that Encourages Earthworms
The quality of your soil affects the population size of the earthworms in your garden. You, therefore, need the perfect soil conditions for the right number of angleworms.
In order for earthworms to appear in your garden and increase in number, ensure that you:
- Till your soil less often. You want to minimize all traffic on your soil, especially in wet conditions. Heavily compacted soil strains earthworm activity as it makes it hard for them to move through. You should also reduce plowing as it reduces night crawler numbers. Over time, you’ll find more of these earth creatures in zero-tilled areas than in plowed ones.
- Improve drainage. Mounding soil and draining it in wetter areas is a good way to prevent waterlogging. Angleworms need just the right amount of moisture and aerated soil.
- Introduce compost and manure in your garden. Many earthworm species find animal dung appealing for its nutritional benefits. You can ensure that earthworms get enough food by applying these farming practices:
- Green manure crops: These are fodder crops that are turned into the soil. They supply organic matter that benefits the future crop. You can graze, slash, or even pulverize present crops and then leave them on your soil.
- Permanent pasture. This practice supplies organic matter when roots and leaves die and decay. Manure from grazing animals and slashings provides organic matter in a pasture.
- Rotations. You can rotate your pasture with crops to help build up organic matter and angleworm numbers.
- Crop stubble. Stubble is considered a great source of organic matter. Leave it to rot onto the soil instead of burning it. Otherwise, you’ll be destroying your surface organic matter and reducing earthworm numbers. Sow crops into the stubble by using minimal cultivation techniques such as:
- Direct drill
- Aerial sowing
- Minimum tillage
- Don’t remove organic matter on the soil’s surface. To protect soil from extreme temperatures like drought and frost, organic matter is crucial. When it’s covering your soil, it reduces the unwanted effects of climatic extremes by retaining moisture.
In fact, you should add organic mulch to your soil for better moisture and a cooler temperature. Your friendly little creatures can lose 20% of their weight on a daily basis in castings and mucus. Mulch reduces moisture evaporation and decaying organic matter holds it in the soil.
You can use leaf litter, dead roots, straw from dead plants to feed earthworms. These are the main agents in combining soil with dead surface litter. This makes the leaf litter more accessible to decomposition by the microorganisms in the soil.
- Stop using chemicals. Fertilizers, like ammonium sulfate that are highly acidifying, and some fungicides are bad for your crawlers. They reduce earthworm numbers and ruin your soil structure, creating a peaty surface.
The perfect soil needs:
- The right amount of moisture as angleworms are made up of 80% water. It shouldn’t have too much moisture, however, as angleworms breathe through their skin.
- To be loamy and not too sandy. If it’s overly sandy, then it will dry out faster, which takes away moisture.
- A balanced pH level, preferably at 7, although levels between 5 and 8 will do.
- Temperature between 50 and 60 degrees as angleworms are cold-blooded creatures.
- Seasons affect populations. Adult earthworms die in the summer and young ones hatching in the fall.
Learn How to Take Care of Your Garden and Grow More
Knowing how to increase the number of earthworms in your soil is only part of gardening like a pro. There’s a lot more that goes into it and you need to ideally find all the crucial information in one place.
Luckily, the Gardening Channel is that place. It’s a website with everything you need to know about gardening. Here you can find advice, techniques, and knowledge about:
- Different plants to liven and beautify your garden.
- Various fruits and vegetables you can grow at home.
- Proven organic gardening methods.
- Pests, diseases, and other threats to your green corner.
- How to take care of your soil.
- Nutritional information for a healthier lifestyle.
- Reviews on helpful gardening products.
- And so much more…
Become a gardening expert today by exploring the world of the Gardening Channel.