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Keeping Compost Worms Healthy And Happy: A Complete Guide

Keeping Compost Worms Healthy And Happy: A Complete Guide

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Paul Brown

For some time now I have been using worms to recycle organic waste and food scraps into valuable soil medium for growing plants. The process, called worm composting or vermicomposting, allows worms to feed on the nutrient-rich food scraps and then turn these into nutrient-rich compost. It is an excellent way to reduce waste and help the environment. Best of all, I can do it indoors which makes it great for someone living in an apartment or cold environment where traditional composting isn’t practical.

But how do you know if your compost worms are happy and content? You can tell that compost worms are happy and healthy if they multiply and produce compost that does not stink. The key to happy and healthy compost worms is to give them a good home, adequate food, and maintain the right conditions in the compost bin.

For those who are new to composting, there are several factors to be considered when setting up a compost bin. It helps to know how much food is adequate for the worms, what environmental conditions are right for them, and what things should be avoided.

How to Tell Whether Compost Worms Are Happy

You can tell that your compost worms are happy and healthy by looking out for three signs:

  1. They reproduce. Worms can easily double their population every 90 days, given the right environment. So even with only a few worms at the start, you can expect them to multiply, fill the compost bin, and eventually meet whatever demand for recycling organic waste that you have.
  2. They produce compost. Worms need to eat to produce worm castings. And for them to do this, they first need to stay alive and thrive.
  3. The compost does not stink. A bin with a healthy environment for worms should not smell foul. If the bin stinks, it may mean that there are too many food scraps that the worms cannot keep up with and cannot digest. The scraps may be too big to break down, or there is food waste that shouldn’t have been added in the first place.

How to Keep Compost Worms Happy and Healthy

Several things guarantee that compost worms are happy and content.

1. Adequate Feeding

Ensure that worms have enough kitchen scraps, but don’t overfeed them.

People tend to throw in every little fruit and vegetable scrap into their compost bin, but the worms might not be able to keep up. This would cause unconsumed food to mold and rot. When this happens, the bin can begin to smell.

If you are noticing that the food is not being consumed before it begins to decompose, ease off of the amount you are feeding and see if the worms can catch up. Click here to learn how long red wigglers can go without food.

2. Feeding the Right Food

Even compost worms need a healthy diet. Their ideal diet consists of:

  • Non-acidic vegetable scraps
  • Non-acidic fruit scraps
  • Grains
  • Teabags
  • Coffee grounds

Other compostable materials like grass clippings, herbivore animal manure, hair, and shredded brown cardboard can also be added.

Avoid giving them food scraps that would take too long to break down, as well as food items that can quickly spoil the bin. Examples of food items to avoid are:

  • Processed food
  • Oily food and sauces
  • Yogurt
  • Meat scraps
  • Leftover dairy products
  • Pineapple and other acidic fruits
  • Watermelon rinds and other food that is hard to break down*

Note: Melon rinds can actually be great for worms when you have a healthy population. Just manage the amount you put in at one time since it can day a few days for them to break it down.

Moreover, when choosing the right food, make sure that food scraps are cut into smaller pieces as they break down faster. Doing this will discourage pests like flies and rats and will help reduce odor.

If you notice that your worms are not eating, something is likely out of balance. Read my troubleshooting guide for worms that won’t eat.

3. Ensuring the Right Conditions for the Compost Bedding

Worms like their bedding moist, so the compost bin should not be left to dry out. At the same time, it should not be flooded with water. People often refer to the liquid that drains from the bottom of a bin as worm tea but it’s not. It can actually be toxic. But it is a sign of adequate moisture in the bin. You can read more about the liquid and troubleshooting it in this article.

Here’s how to test if the moisture level is just right:

  1. Pick up a handful of bedding and squeeze it.
  2. See if it feels like a properly wrung-out sponge. It should feel wet, but water should not come out.
  3. If it doesn’t feel wet, add some water. If water comes out after squeezing, add more bedding material to even out the excess moisture or bore additional drainage holes at the bottom of the container. It may also help to add additional air holes along the top to facilitate moisture evaporation. Click here to learn more about the importance of air holes for maintaining proper moisture levels.

Do this moisture test regularly.

A dried-out bin would dehydrate the worms and leave them unable to breathe and tunnel effectively. On the other hand, a bin that is flooded or too wet would drown the worms. A bin that is too dry or too wet would be stinky because the worms would die out and won’t be able to eat the food scraps.

4. Remembering to Harvest Worm Castings

Don’t allow the compost bin to fill up with worm castings. It’s time to harvest finished compost or worm castings when the worms have gone through all the bedding material, and the bin is already full of dark brown and earthy compost.

It is also time to harvest if the worms have already been in the bin for at least three months.

5. Maintaining the Right Temperature

Composting worms thrive at a specific temperature range. Place the bin at an ideal location, and don’t leave it too hot or too cold.

In the summertime, make sure that the bin is not in direct sunlight. First, they don’t like the light. But more importantly, a worm bin baking in the sun all day can literally cook them. Bedding temperatures above 84 degrees Fahrenheit can result in worms dying (source). So pick a shady area and check in on the bedding temperature every now and then. And here’s a “cool” trick. On warmer summer days, use ice instead of water for moisture. It melts slowly, allowing for a more even distribution of moisture. At the same time, it cools the bedding for the worms.

Meanwhile, a temperature of below 50 degrees can slow them down. A temperature that is below freezing point could kill them so during the winter seasons they should really be kept indoors or at least in a garage or insulated shed. I also recommend using bin blankets for a little extra protection when keeping them in a garage or shed.

If the environment conditions are right and they are fed appropriately, you will have healthy and happy worms that will focus their time on turning kitchen scraps into soil. If the environment is out of balance, however, you will likely find them trying to escape their bin.

Compost Bins For Healthy And Happy Worms

Providing a good home for compost worms is very important for them to thrive. You can build your own (more on that later) or buy a manufactured vermicomposting bin. These commercial containers and beddings are designed to provide the right conditions for the worms to be healthy and to make harvesting compost easy. Below are a couple of the most popular manufactured worm farms. Note, if you are considering this as a project for kids, consider a see-through worm farm designed for this purpose.

Worm Factory 360 Worm Composting Bin

This is a stackable worm bin that comes with four trays (but is expandable to eight) and has a fluid collection reservoir and spigot to drain excess fluid. The lid converts to a stand to help while harvesting castings and it comes with the popular “What Can Red Wigglers Eat” Refridgerator magnet.

The way stackable bins work is that you usually begin with one tray. As the food and bedding are composted, you add another tray on top. The worms will move upward and continue composting food items as you add trays. You are then able to harvest from the trays below as the worms move out of them. Pretty nifty concept.

This is a complete starter kit that comes with a DVD instruction manual and some bedding material. Just add food and worms. It is a great option for someone just getting started.

Click Here to get the latest pricing (link to Amazon)

4-Tray Worm Factory Farm

Similar to the Worm Factory 360, this system also uses the tray principle that allows you to continuously add food to a top layer where the worms slowly migrate to while leaving behind finished castings and compost in the lower trays. it includes a reservoir and spigot like the Worm Factory 360 but where this model stands out is in its size.

At only 9 x 12 x 8.5, this tray would be at home in an apartment without taking up too much space. In fact, it’s about half the floor space of the Worm Farm 360. And it generally costs quite a bit less as well. The only downfall is that less space means less composting can take place. So it really comes down to personal preference and needs.

Click here for pricing on the 4-Tray Worm Factory Farm (link to Amazon)

Worms Can Be Just As Happy In A DIY Worm Bin

Instead of buying a commercial worm bin, consider going DIY. Get a large shallow plastic box with a lid. The ideal plastic container should be eight to twelve inches deep. A box that is 20 inches in width by 30 inches in length is also a good size.

Bore ventilation holes on the sides of the box and drain holes on the bottom of the box.

Worm bin air holes
Air holes on the sides of a DIY worm bin

Pro tip: Worms like a dark and moist environment, so make sure that the box is opaque or plan to keep it in a dark area.

The lid of the box will ensure that the moisture is retained and helps to keep rodents out if placed outside. Be sure that you place a tray under the bin to catch the drips from the drain holes. A great way of doing this is to get two identical containers and set the main one (with holes in the bottom) inside the other. It creates a space where excess fluid can drain away from the bedding.

Worm Bedding Is Important For Healthy Worms

The bedding material for the compost provides the food source for the worms. It also helps moderate the bin’s moisture levels, controls odor, and ensures proper aeration.

Typically, the worm bedding is made of dry leaves or shredded newspaper or cardboard. There should be enough of these materials to fill half or a third of the bin.

Soak the bedding as worms prefer their environment to be at about 75 percent moisture level. Shredded newspapers can be soaked in water for a few minutes. It can help to soak cardboard and paper boxes overnight.

After soaking, wring the bedding material out until these are moist but not dripping. Place the bedding in the bin. Add something gritty such as fine sand, soil, sawdust, leaves, cornstarch, or ground eggshells. The gritty material will help the worms grind up the paper and the food as they don’t have teeth.

All About Those Happy Compost Worms

How Do Worms Turn Garbage into Compost?

Some of the questions beginners ask about compost worms are:

  1. What kind of worms are used for compost?
  2. How many worms to get?
  3. How to feed the worms?
  4. How long do compost worms live?
  5. How do worms multiply?

What Kind of Worms to Use

There is a right kind of worm to use for vermicompost. The most common worms using are called red worms or red wigglers, also known as Eisenia fetida, and they are available from a worm farm or a composting supplies provider. You can even buy them online and have them delivered to you (link to Amazon).

Manure worms, also called as Lumbricus rubellus, can be used as well but I don’t have any experience with them. I can tell you that you don’t want to use regular earthworms for this. Earthworms (nightcrawlers) are not the same as compost worms and require a different living environment to thrive.

How Many Worms are Needed to Get Started?

The amount or number of worms you should get depends on how much food scraps your household generates each day and how big of a bin you are planning to use. This ensures that the worms have enough food and space.

Most vermiculture experts recommend starting with a small number of worms. That translates to around two pounds of wigglers, or roughly 2,000 worms, for every pound of food waste per day. Seriously, I would recommend just getting around 250 to start. You can always add more. But, if you are wanting to go all-in, there is a simple formula for determining how many worms you need.

Do an audit of the household’s food waste and track the average amount of food scraps generated. Here’s how:

  1. Collect a day’s worth of scraps that the worms can eat and place them in a plastic bag.
  2. Weigh the bag of scraps.
  3. Do this every day for a week and record the weight of scraps.
  4. Get the average weight, which is the daily average food scrap.

That’s the sciency way to go about it. What I did was to simply start with 250 and learn how much they could eat. I can add more worms later and increase the amount of food. If you want to know more be sure to read Vermicomposting: How Many Worms Are Needed?

Putting the Worms in the Bin

Make the worms feel at home by digging down until the middle of the bedding then placing them there instead of just leaving them on top. Put the lid back on and leave the worms alone to settle in for about a week. Within this time, the worms will feed off the bedding.

Feeding the Worms The Right Way To Keep Them Happy

Start feeding the worms scraps after about a week. It is also best to feed them in small amounts once a week. Feeding the worms more than they can process will result in the compost bin stinking. Worms can go up to two weeks without food so I really suggest starting light and adding more food as you go.

Ideally, compost bins should not smell. The rotting food items that the worms have not eaten yet are one of the most common reasons for nasty odor in a worm bin.

Here are tips to avoid food rotting in your worm bin:

  • Cut food scraps into small pieces so it is easy for the worms to eat them before they start to spoil.
  • When putting in food scraps into the compost bin, make sure to cover them with moist paper and dirt. The reason for that is because exposed scraps could attract fruit flies and other pests.
  • Observe the worms and check if they are eating the food scraps. Remove the scraps that they haven’t eaten for a while, as this means that they don’t like them.

How Long Do Compost Worms Live If They Are Healthy?

There are a lot of crazy answers on the internet about this but I’ve checked a lot of literature and cross-referenced several university agricultural websites. Compost worms can live 2-7 years on average assuming they are healthy and provided with the essentials of living that they require. (Example source of this information).If one dies, it is hardly noticeable. A worm’s body is about 90 percent water, so it will just shrivel up and mix with the compost.

Inside the bin, new worms are born, and old ones die all the time. Read this if you are noticing clusters of dead worms.

How Worms Reproduce

Worms are hermaphrodites, which means that each one is both male and female at the same time. However, two worms are still needed to mate and reproduce. Mating involves the two worms lining up in opposite directions near their clitellum or band, where their sexual organs are found.

For about 15 minutes, the worms are attached as they exchange sperm cells. Several days after mating, eggs come in contact with the sperm cells, forming a cocoon. This cocoon separates from the worm, and fertilization occurs. There are two to five baby worms contained inside one cocoon.

The baby worms live in the cocoon for at least three weeks, depending on the environmental conditions. During the winter, for instance, baby worms may stay in their eggshells for several weeks more until the air warms up again.

A great book for those just getting started with vermicomposting is The Worm Book For Beginners (2nd Edition). It’s available in paperback or on Kindle at Amazon. Click here for current pricing.

Worm Castings

Create a favorable environment for compost worms, and they will eat the food waste and produce compost or worm castings. This is just worm waste, but it makes an organic form of fertilizer. Finished compost looks brown and earthy.

You will notice over time that there is less and less bedding in the compost bin. After three to five months, the bin will be filled with finished compost, which means that it’s time to harvest the worm castings.

How to Harvest Worm Castings

Harvesting means removing the worm castings from the bin. When they are in high concentrations, these castings will be unhealthy for the worms. Therefore separating the two helps maintain a healthy environment.

There are several methods for harvesting worm castings. Here are two of the common ones:

Moving Everything

This method involves pushing all the contents of the worm bin to one side, leaving the other half empty. While doing this, remove any large pieces of undecomposed newspapers or food. Put fresh bedding on the empty side of the bin while also burying fresh food scraps.

Over the next two to three weeks, the worms will migrate to the side where the fresh bedding and food are. As they do this, they will conveniently leave their finished compost behind in the other half of the bin. Once migration is done, remove the finished compost and put fresh bedding on the empty side.

You can further facilitate the move by covering only the new side of the bin. The worms will move to where it is dark. Moreover, the old side will dry out, and this will encourage the worms to leave for the new, covered, and moist side.

Hands-On Method

This method involves dumping all contents of the worm bin onto a sheet of paper or plastic. Make several cone-shaped piles, each containing worms, bedding, compost, and undecomposed food. As the individual piles are exposed to light, the worms will move to the bottom where it is dark.

Take out the top layer of compost from the pile and remove undecomposed newspaper bits and food. Let the remainder of the pile sit under the light for a couple of minutes as the worms burrow down. Afterward, remove the lower layer of compost.

Repeat until all the worms in all piles have moved down to the bottom. Collect the worms and put them back in the compost bin with fresh bedding.

Here’s a short video from YouTube on how to harvest castings.

Worm Casting Harvest - Quick and Simple!

Other Things to Avoid When Worm Composting

To make sure the compost worms stay healthy and happy, there are a few more things to keep in mind.

  • Do not mix fresh horse, chicken, or cow manure into the bedding. Fresh manure emits gases, and this will raise the compost bin’s temperature.
  • Do not dispose of plastic, aluminum foil, or glass in the compost. Avoid adding sponges and rubber bands.
  • When using paper and cardboard as bedding material, do not include those with colored printing on them. Colored inks can be toxic to worms.

Benefits of Worm Composting

Using worms to recycle organic kitchen waste and create compost to fertilize plants is easy once one gets the hang of it.

Other reasons why people should give worm composting a try include:

  • Worms work all year, even during the winter. Even when it gets cold, you can just move the compost bin indoors or to an insulated shed. This is what first attracted me to vermicomposting, a way to continue composting through the winter months.
  • Worms work fast. Worms can eat the food scraps and convert these into compost for plants in less than two weeks.
  • Worm castings are good for plants. Top-dress plants with finished worm compost and they will grow healthy. This is because worm castings are very rich in nutrients and would make perfect fertilizers.

Keep Compost Worms Happy and Healthy 

Compost worms can help households reduce and recycle organic waste, so there won’t be any need to throw it out. And the compost they produce is beneficial for gardens, flower beds, potted plants, or anything else that thrives in nutrient-rich soil.

So, learning how to keep compost worms happy and content is a small price to pay for all the benefits people can enjoy from them.

Read all of our vermicomposting articles to learn about setting up, troubleshooting, and maintaining a happy and healthy worm farm.