Earthworms are very beneficial, and you will mostly find them in healthy organic soils. They eat fungi, bacteria and decomposing matter that then turn into worm castings when they excrete it. Their worm castings (vermicompost) are filled with nutrients that help to improve the soil and also help plants to grow healthily.
Soil that has earthworms present is much better at creating fertile conditions, than soil that doesn’t have any. They help to till the soil when they tunnel under the ground, and these tunnels help the moisture and air to get into the soil better. This then creates a much better environment for any plants that are growing within it.
These tunnels that they create help to serve as water reservoirs, that help to store water for plants to drink. They also hold air pockets that help bacteria break down organic matter within the soil.
There are many species of earthworms. But the most common advantage that they all have is that they increase the decomposition speed, they till and aerate the soil, they also help in mixing soils for it to be more beneficial.
A prime example of a worm is the red wiggler, which is easily the number one for vermicomposting. They are the popular choice for compost piles, garden soil, and they are perfect for worm farms. Because they are so good at their job, it is very wise to make sure you have a good population of them in your soil.
How to increase the population of earthworms in your soil
The easiest way to increase the population is to buy the worms and manually add them. You can buy them in stores and online, which is an excellent short term fix. But they still need the right kind of living conditions, and you will want them naturally to arrive and multiply.
To attract them, you need to have soil that that is ideal for them in their natural habitat. With the right kind of soil, they will naturally arrive without the need for you to manually add them. But what is the ideal living conditions for worms?
Worms are attracted to organically-rich soil that has plenty of nutrients, and a neutral pH level. Because of this, you need to make whatever changes that are necessary to achieve this type of soil. This can be done quite easily if you follow these simple steps.
Firstly, you need to check what the pH level is in your soil. You don’t want it to be too acidic or too alkaline, and ideally as close to neutral as possible. The easiest way to check it is with a pH testing kit. You want it to read as close to 7 as possible (below 7 is acidic and above 7 is alkaline).
If you have soil that is too acidic, you need to raise the pH level. Wood ash is a good way to do this by mixing it into your soil. If it is too alkaline, you need to lower the pH level. Compost or mulch can be mixed into your soil to lower the level. But it will take time for it to readjust.
Don’t get too stressed about this because a neutral pH level of 7 is their ideal living conditions, but they are still attracted anywhere around the 6-8 range. Although a 6 is much more preferred to an 8, and the pH level will naturally lower as you add organic materials.
Before you add any organic material, you must till first. Tilling is when you break up and plow the soil, using either hand tools (a rake, etc), or an actual tiller, and then mixing in the organic matter. When you are tilling, you need to go at least a few inches deep, but no further than 1 foot.
The best type of organic matter to add is anything compostable or well-rotted compost. This is perfect for adding material into the soil that will attract worms for them to feast on. When this is done, you should leave it for a couple of months. It’s not an overnight thing and will take time for any changes to take place.
After a couple of months, dig between half a foot to one foot deep, and check how many worms are there. You need to dig this deep because different types of worms prefer to live at different depths typically. You should be able to see an increase in population by this time, and your soil should be a lot more enriched and fertile.
This will provide perfect living conditions for the worms and will encourage them to stay and multiply. Anything that you plant in that space will grow much healthier than if you planted them a couple of months before, and with higher yields.
You will benefit from checking the pH level and how many worms are present, every couple of months. You can then monitor how your soil is performing, and if there are any issues, you can rectify them. Adding organic matter, compost, or mulches will sort out most problems.
The last thing you need to consider is when the temperature drops, but more importantly when the frost sets in and throughout winter. Worms tend to die off in the wintertime, especially red wigglers (because they prefer to dwell not too deep in the soil).
Before they die off, they lay their eggs first, and each egg typically contains multiple baby worms. This is how nature ensures that they carry on existing. But you can also help them to survive winter, by insulating the surface of the soil throughout the colder months. I have written a whole article on this here: This Is How You Can Make Compost Worms Survive Winter.
Earthworms are very beneficial because they eat organic matter, etc and excrete it into castings. These castings are great at creating fertile soil for plants to grow healthily. To encourage them and increase the population, you must provide them with the perfect living conditions. They love to live in a pH-neutral soil that has been freshly tilled, with plenty of organic matter, compost, and mulch to eat.
Creating this type of habitat can be done quickly, and with very little effort. But it takes a couple of months for anything to start to get going. They will naturally arrive, multiply, and can also be protected from the frost. You will end up with a more nutrient-rich type of soil, that has a nice population of worms, and is perfect for growing plants.