I’ve had tens of thousands of worms in my kitchen in years past, and I’ve never once tried to get rid of them. Now, after transitioning from full-time travel to a homestead, I’m acquiring several thousand more.
We don’t operate an invertebrate zoo. We’re using worms to help reduce our food waste and provide free compost for our garden.
Many people already know about the benefits of having a compost pile in their yard. However, vermicomposting is another option for reducing food waste and creating rich, fertile compost for your garden. This free compost can help you grow healthier plants with higher yields.
However, vermicomposting isn’t quite as simple as you think. If you’re not careful, your worm bin can turn into a smelly, wet mess you dread opening each day.
I’ve started and maintained several worm bins over the past decade, and I can tell you firsthand there’s a learning curve to vermicomposting. But starting a worm bin is a fantastic learning experience, especially if you have kids. Your worms can provide you with rich, high-quality, nutritious compost that’s far more beneficial than anything you can buy at the store.
What Is Vermicomposting?
Vermicomposting uses specific earthworm species to break down food waste and turn it into rich, nutrient-dense compost you can use in outdoor home gardening or container gardening. Red wigglers are most popular because they consume matter near the surface — unlike other worm species, such as night crawlers, that burrow much further down to feed.
Vermicomposting uses closed bins that create a dark, hospitable environment where worms can thrive, reproduce, and consume organic matter. When the worms digest the organic matter, they produce worm castings, which are worm excrement. These castings, along with uneaten organic matter in the bin and helpful bacteria, are the compost.
Pros of Vermicomposting
Most people don’t daydream about having a bin filled with thousands of worms eating all their food scraps and leftovers. However, vermicomposting is becoming more popular as people look for ways to live a zero-waste lifestyle and minimize their impact on the environment. And when done correctly, vermicomposting can provide you and your garden several benefits.
1. It Helps Eliminate Food Waste
According to the United States Department of Agriculture, Americans waste 30% to 40% of the food supply each year, which averages 218.9 pounds of food per person. The Guardian estimates this waste costs the average family of four over $1,600 per year.
One of the most significant advantages of vermicomposting is that you get to see how much food your household wastes daily or weekly. Every time you toss leftovers you didn’t eat or fruit that went bad, it’s like watching money go down the drain. That can motivate you and your family to make changes to reduce food waste and save money on groceries.
When you vermicompost, you don’t waste any food. You get rich compost and highly beneficial “worm tea” (a liquid fertilizer made from soaking worm castings in water).
2. It Helps Reduce Greenhouse Gasses
Vermicomposting benefits the environment by reducing greenhouse gas emissions.
When organic matter decomposes in landfills, it produces high levels of methane gas, which according to National Geographic, is a greenhouse gas 28 times more potent than carbon dioxide when it comes to warming the planet. Giving your worms your leftover food and kitchen scraps keeps all that waste out of landfills and helps reduce emissions. Although the food emits some methane as it decomposes, it’s dramatically less than the methane produced in a landfill.
3. It Leads to Better Plant Growth
A 2019 study published in the Journal of Pharmacognosy and Phytochemistry found significant increases in nutrients like potassium and carbon in vermicompost compared to soil without compost. And a 2016 study published in Ecological Engineering found that vermicompost stimulates the growth of beneficial fungi and bacteria.
All these nutrients provide an essential boost for plants, help aerate the soil, and aid with water retention. And there’s plenty of scientific research to back that up.
A 2008 study published in Bioresource Technology found that vermicompost improved root formation, shoots, and leaf area in some plant species. A 2007 study, also published in Bioresource Technology, found that soil enriched with vermicompost had significantly higher tomato yields.
Additionally, a 2006 Ohio State University research article published in BioCycle says that even minimal amounts of worm tea added to tomato plants positively affected growth and crop yield.
A 2009 Griffith University study published in the American-Eurasian Journal of Agricultural & Environmental Sciences notes that because vermicompost is rich in beneficial nutrients, microorganisms, and minerals, plants are better able to resist pests and disease.
4. It Provides Compost More Quickly
Depending on your compost pile’s location and temperature, it can take three to 12 months to get usable compost from a conventional outdoor pile.
With vermicomposting, most people get usable compost in three months or less. And you continue to get compost every two to three months after that.
5. You Can Compost Indoors
Even if you don’t have a backyard or garden, you can still try vermicomposting. Many people living in apartments keep a worm bin in their kitchen or closet to reduce their food waste and have a steady supply of rich compost for their houseplants or container garden.
Cons of Vermicomposting
When maintained correctly, a healthy vermicompost bin smells earthy and natural. It’s free of pests and noticeable insects. However, it can be challenging to keep a vermicompost bin’s environment at perfect levels to avoid these problems, especially when you’re still learning how to maintain that balance. So there are definitely some downsides to starting a worm bin.
1. It Can Create Odors
Worms can only eat so much food per week. If you put too much food in your worm bin, it quickly starts to smell. Poorly ventilated containers also develop foul odors and too much moisture.
If your worm bin is too wet, foul-smelling leachate (a dark anaerobic liquid that collects when too much moisture develops) can pool at the bottom. This leachate isn’t the beneficial worm tea so many gardeners rave about. It smells terrible and can drown your worms. It could also contain toxins or bacteria that can make you or your worms ill.
2. Maintenance Can Be Time-Consuming
Vermicomposting doesn’t require a daily commitment. However, it does take as much or more time than a conventional compost pile.
For example, your worms can process food scraps faster if you cut them into small pieces or process them in a blender. Many people don’t have the time or inclination to prepare their food scraps.
3. Harvesting Is Time-Consuming
Harvesting your compost can take an hour or more. But commercial worm bins have trays to make harvesting the compost much less time-consuming.
You don’t need a lot of gear to start vermicomposting. You can spend a couple hundred dollars buying meters and a commercial bin, or you can make your own for a lot less.
There are plenty of worm bins available on Amazon. These range in price from $50 to $150 or more.
The advantage of buying a commercial bin is that they come with several different levels. As the worms eat all the organic matter in one level, they migrate to the next level in search of more food. Once most worms have vacated a level, you can pull it out and harvest the compost inside. Since there are far fewer worms to deal with using this system, it saves a significant amount of time during compost collection. With a DIY worm bin, you’re going to spend a bit more time harvesting the compost every few months.
Most commercial worm bins have a drainage level at the very bottom to collect any leachate that forms. Many of these bins also have a spigot that makes it easy to drain off excess liquid.
The downside to commercial worm bins is the expense. However, they can save you time down the road, so it’s a definite trade-off.
There are several quality worm bins on the market, and each has its benefits and drawbacks.
Worm Factory 360 Composter
My favorite commercial worm composter is the Worm Factory composter, which costs $120 plus shipping. It’s the last commercial composter I purchased, and it’s high-quality, affordable, and easy to use.
The standard Worm Factory Composter comes with four trays, which is more than enough to get started. You can expand it with more trays, each costing around $25, if you have a significant amount of food to compost each week. So it’s an appropriate choice for larger families. There’s also a handy quick-tips sticker on the lid for troubleshooting problems.
Can O Worms Composter
The Can O Worms composter was the first commercial worm bin I purchased. This model held up well, but it only comes with two trays, which means you have to harvest compost more often. However, it’s a larger composter, with dimensions of 20 inches by 20 inches by 25 inches, so it can accommodate quite a lot of food. That makes it a suitable choice for families or people who generally produce a lot of food waste each week.
The Can O Worms composter sells for around $100. While it’s a quality product, it’s a bit expensive and you get fewer trays than with the Worm Factory 360. You can purchase more trays for $40 each to expand your composting capacity.
Hot Frog Living Composter
The Hot Frog composter, which sells for $130, is a fun worm bin from Uncle Jim’s Worm Farm. It’s one of the most attractive worm bins on the market, making it a better option if you’re keeping a worm bin in your kitchen or hallway. It also has maple wood legs, which elevates its style a bit more than other brands, and comes in four colors.
One unique feature of the Hot Frog is its moisture-retention tray along the outside edge. It helps keep the bedding along the walls from drying out. Other worm bins don’t have this feature.
The downside to the Hot Frog is that it’s a smaller system. It’s 3 inches smaller in diameter than the Worm Factory Composter, and you only get two trays. It’s challenging for larger families to use this bin unless they invest in additional trays, which are $40 for two. That said, this composter is ideal if you live in a small space. Some people have even stored it in their bathroom between the toilet and sink.
This composter has gotten rave reviews from past customers (4.8 stars out of 5 on Uncle Jim’s and 4.3 stars out of 5 on Amazon). Many reviewers say it’s an excellent beginner worm bin, especially if you have children (mainly due to its fun look and ease of setup).
If you don’t want to invest in a commercial worm bin, there’s good news. It’s relatively easy to make one yourself, and you likely already have some of the supplies you need around the house.
You can use almost any container. Most people use a plastic storage tub because it’s easy to find an empty one lying around the house — and if you can’t, they’re affordable.
Make sure any bin you choose has opaque sides. Worms hate the light and will not thrive in a clear plastic bin. The lid must fit tightly and have no holes.
You also need to select the right size container for your needs. The best way to determine how big a bin you need is to collect all the food your family throws away during the week and weigh it. You need to provide 1 square foot of space in your bin for every pound of waste you add to the container each week. For example, a family of four typically produces around 6 to 8 pounds of food waste each week, so a 1-by-2-by-3-foot bin can accommodate 6 pounds of food.
It’s also vital to note that healthy and balanced vermicompost bins don’t create leachate. If this is your first worm bin, you’re bound to overfeed at some point, but you can add drainage holes to your bin if you have two identical or similarly shaped and sized bins.
Once you’ve chosen your containers, it’s time to turn them into a worm bin.
- 2 identical worm bin-suitable containers
- Drill outfitted with a 1/4-inch bit
- 4 bricks
- Using your drill, make ventilation holes spaced 1 to 2 inches apart around all 4 sides of the top edge of the bin you plan to use as your worm bin. (Do not drill holes in the lid. If you’re keeping your worm bin outdoors, you don’t want the rain to seep in.)
- Flip the bin over so the bottom is facing up. Use the same drill bit to make several rows of holes spaced 3 inches apart in the bottom of your worm bin. Space the rows 2 to 3 inches apart.
- Next, put the bricks in the corners of the hole-free bin you’ve designated as your collection bin. Stack the worm bin on top of the bricks inside the collection bin so the bottom is on the bricks and not touching the bottom of the collection bin. The idea is that any excess water in the worm bin will drip into the collection bin.
- When you need to empty the excess liquid, pull out the worm bin and dump the water in the collection bin outside or in the sink.
There are several other ways to incorporate drainage into a DIY worm bin, and all are easy and inexpensive to do. There are also other methods of building bins for those with the skills necessary. You can find full instructions on worm bins with drainage capabilities at Zero Waste Guy and Compost Junkie.
Bedding & Grit
Bedding is the bulky, moist material where your worms live while they settle in and start eating food scraps. The bedding also provides a good source of carbon. Cornell University Waste Management Institute notes carbon provides energy for the beneficial microbes that aid in the decomposition process. The bedding also helps absorb moisture and maintain airflow. Add enough bedding so your bin is three-quarters full.
There are many materials you can use for bedding, and your best bet is to use two or three different materials if you can. That allows you to use the strengths of each material to create a balanced bedding. Appropriate options for bedding include:
- Shredded newspaper is readily available, breaks down easily, and is inexpensive or free. Just avoid using any glossy paper, as it contains chemicals that might harm your worms.
- Peat moss helps maintain proper airflow in the bin. You can purchase peat moss at most garden centers. However, it’s costly over time. Also, read the ingredients on the label carefully to ensure it doesn’t contain chemicals, which can harm your worms.
- Coco coir is made from coconut husks. It makes excellent bedding for worms because it’s clean, absorbs moisture well, and breaks down quickly. However, it’s imported and relatively expensive, especially long-term. That said, if you have some left over from another project, you can toss the remainder in your worm bin.
- Straw is readily available in rural areas and very inexpensive. It’s beneficial to add to a worm bin because it promotes airflow. However, it doesn’t retain water well, so you must mix it with other materials, such as shredded newspaper, so the bin doesn’t get too dry.
You also need a top layer of material to help keep the worms from crawling out the first few days, which they’re prone to do in a new home. After roughly 48 hours, they become accustomed to their new home and stop trying to escape. You can use whole pieces of newspaper or cardboard for this layer. You can also discourage escapees by putting a bright light on the worm bin at night. A lamp placed on the lid works best. Worms avoid light, so they’ll stay safely inside to avoid it.
Also note that worms have a gizzard (just like birds), so they need sand or other types of grit, such as finely crushed eggshells or vermiculite, to help them digest their food. When you mix the bedding, add a handful of your grit and mix it thoroughly.
I recommend purchasing red wigglers from Uncle Jim’s Worm Farm. I’ve bought worms from this company several times, and they’ve always arrived healthy and strong.
The number of worms you purchase depends entirely on how much you want to spend and how quickly you want a fully operational worm bin. Under the right conditions, your worms will double their population every 90 days. That means if you purchase 250 worms, you’ll have 500 worms in three months.
Buying fewer worms costs less, but it takes longer for your worms to reproduce enough to handle large amounts of food waste. For many families, purchasing 500 worms is a good starting point. Worms self-regulate their population. When they reach the maximum number that can survive in the bin, their reproduction rate declines, so you won’t ever have too many worms.
Timing your worm purchase is also critical. Worms shipped in the middle of winter can arrive frozen and dead, while worms shipped during a heatwave can die from overheating. Whenever you purchase your worms, try to be home the day of the delivery so they’re not languishing in your mailbox for hours.
Farms often pack worms in a dry material, such as peat moss, so they slowly dehydrate. This dehydration puts them in a dormant state so they better survive the trip. So you need to put them in a moist bin as soon as possible. Most worm farmers recommend pouring a half cup of water over your worms as soon as you open the box and then immediately put them in their new home.
Food Compost Container
Find a storage container to store food scraps in during the week. While you can use any size or type of container for scrap storage, you’ll likely be happier splurging on a food compost pail with an activated charcoal filter. These food compost pails do an excellent job of keeping odors at bay, and the tight-fitting lid helps prevent a fruit fly infestation.
Worms eat a wide variety of things we usually throw out. And while they have voracious appetites once they get going, there are some do’s and don’ts for feeding them.
Scraps your worms will thrive on include:
- Most Low-Acid Produce Scraps and Peelings. Worms love apple rinds, banana peels, cucumber ends, and almost anything else that comes from the garden. Cut harder produce byproducts, such as avocado shells and banana peels, into quarter- to half-inch pieces. Otherwise, they will sit in your worm bin for months or years. Add tomatoes in a limited quantity. They’re acidic and will upset the worm bin’s pH balance.
- Eggshells. You can add eggshells to your worm bin if you crush them into small pieces. There’s no need to rinse them, but don’t put the eggs themselves (raw or cooked) into the bin.
- Beverage-Brewing Remnants. You can also toss in coffee grounds and filters, loose tea, and tea bags (just make sure you take the staple out of the tea bag if there is one).
- Some Paper Products. You can add shredded cardboard or newspaper, torn up paper plates, and paper towels to your worm bin. Just don’t add paper towels you’ve sprayed with cleaner or used to clean up grease or other meat waste, which could attract unwanted pests, especially if your bin is outdoors.
Some foods create foul smells and attract pests. Avoid foods and materials such as:
- Meat Scraps, Bones, and Fats. Avoid putting meat products and byproducts (other than eggshells) into your worm bin. These can attract unwanted pests and rodents and quickly become rancid and smell foul.
- Dairy Products. Products containing milk, including butter, cream, cheese, yogurt, and milk, should never go into the worm bin for the same reason you should avoid meat products.
- Fats, Oils, and Sauces. Don’t add fats, such as bacon drippings, vegetable oil, or olive oil to the worm bin.
- Organic Outdoor Material. Leaves and grass clippings can introduce unwanted pests into your worm bin. These materials can also quickly add too much heat when they break down.
- Moldy or Rotten Food. Some molds that develop on rotting food can harm your worms. It’s safer to put moldy or rotten food in an outdoor compost pile.
- Citrus Peels and Other Acidic Foods. Most worms don’t eat highly acidic foods. These foods also throw off the worm bin’s pH balance. Avoid pineapple, onions, lemons, limes, and high quantities of tomatoes.
- Spicy Foods or Sauces. If your foods contain any hot peppers, keep them out of the worm bin.
Setting Up Your Worm Bin
It’s a good idea to get your worm bin set up before you order your worms. That gives you plenty of time to gather the supplies you need and troubleshoot any problems before they arrive.
- Worm bin
- Bedding material, such as shredded newspaper or cardboard, dried leaves, or coco coir
- A handful of grit (such as sand, eggshells, or vermiculite)
- Spray bottle and fresh water
- 1/2 cup food scraps
- Several whole sheets of dampened newspaper or cardboard
- Food scrap container
- Fill the bin half full with bedding material and add the grit. You only need to add a handful of the grit, regardless of the size of your bin, as the worms need only a small amount to aid digestion.
- Using the spray bottle, wet the bedding thoroughly. Add enough water that the bedding is damp but not dripping. To test the bedding’s moisture level, spray it thoroughly with water, pick up a handful, and squeeze it. The bedding should compress and feel damp but not drip. If it drips, you’ve added too much water. To reduce the moisture, add some dry bedding and mix it thoroughly with your hands.
- Using your hands, dig a small hole in the center of the bedding. Take the worms out of their bag and place them in the hole. Moisten another layer of bedding to the same degree, and cover them with it until the bin is 3/4 full.
- Add the food scraps. Dig a hole in the bedding on one side of the worm bin. Put the food in this hole, and cover it with more moist bedding.
- Layer the whole sheets of dampened newspaper or cardboard on top of all the bedding, covering it completely.
- Put the lid back on and leave them alone for 7 to 14 days so they can get settled in. Once they’ve eaten the food scraps you initially left in the bin, you can begin adding more food.
Caring for Your Worm Bin
Thankfully, worms don’t require a lot of attention. However, there are a few things you need to do weekly to make sure they’re happy, healthy, and thriving.
Feed Your Worms Weekly
The less you disturb your worms, the happier they’ll be, so it’s best to feed them once per week.
When it’s time to feed, open the lid of the bin and dig a hole in the bedding with your hands or a garden trowel. If you use a trowel, dig carefully to avoid injuring your worms. Put the food scraps into the hole you’ve dug, and cover it with enough bedding so that no scraps are visible. Covering the food scraps thoroughly discourages fruit flies and other pests.
In the beginning, you need to monitor how much food your worms eat each week. Don’t add more food until your first half cup of scraps is almost gone. Remember, the bedding also serves as food for your worms, so they’re not going to starve. As the population increases, you can add more food each week.
Monitor Moisture Every Few Days
It’s essential to keep an eye on the moisture content of the foods you’re adding to the bin each week. Some foods, such as watermelon rinds, berries, and tomatoes, are very high in moisture. Adding too many can lead to a wet bin and cascading odor and pest problems. Conversely, if you add too many dry foods, such as bread crusts or oats, your bin won’t have enough moisture for the worms to thrive.
That’s why it’s best to keep an eye on the moisture level every few days. And you can do that without disturbing your worms.
Open the top of your worm bin and peel back the top layers of newspaper or cardboard. Take a handful of the bedding and squeeze it gently. If it drips, the bedding is too wet. To correct this, add several handfuls of dry bedding to soak up excess moisture and avoid adding overly wet food scraps until the bedding is drier. You can also use a moisture meter to quickly and easily check moisture levels.
If you have a DIY bin, check the drainage bin every several days. Worms might try to escape through the drainage holes, and if there’s standing water at the bottom, they can drown.
Bedding that’s too dry is not a common problem, but it does happen. If you squeeze the bedding and it crackles or crumbles, it’s too dry. Spray it with water until it’s thoroughly moist but not dripping. You can also add some wet foods to boost moisture levels. Worms don’t have lungs. They take in oxygen through their skin, and they depend on exterior moisture to keep their skin moist enough for that oxygen to pass through. Your worms can suffocate when the bedding is too dry.
Pay Attention to Temperature
Temperature is also a critical component to monitor. Worms thrive when temperatures range between 55 and 85 degrees F. When temperatures are outside this range, your worms eat and reproduce less. More important, when temperatures are below 35 degrees F, your worms will freeze. When they’re above 90 degrees F, they will overheat and die. Bring them inside when outdoor temperatures increase or decrease to dangerous ranges.
Retrieving Your Compost
There are a couple of different ways to harvest your compost, and the method you choose depends on what type of composter you have.
Each time you harvest your compost, add another handful of grit to the bedding to help aid digestion.
Commercial Worm Bin
Commercial worm bins make harvesting compost as quick and painless as possible.
Your compost is ready to harvest when you notice all the worms have migrated to upper trays looking for food, leaving lower trays with almost no food scraps and full of rich compost.
When that happens, take out the bottom tray and set it on the ground (outdoors) or a tarp (indoors). Dig through the compost and look for any worms left behind. Place them back into the worm bin. When the tray is free of worms, you can use the compost as needed.
To harvest compost from your worm bin, you must first separate the worms from the soil. There are a few ways to do it, but the most common is to take out handfuls of compost (which still has the worms inside) and make small piles on your driveway or tarp-covered floor. Worms don’t like light, so they will gravitate toward the interior center of the compost pile. After waiting 15 to 20 minutes for the worms to move to the interior center, collect the worm-free compost from the top and edges. In the small pile that’s left, pick the worms out of the remaining compost and place them back in the worm bin.
Vermicomposting is a fantastic way to reduce food waste and help reduce greenhouse gasses. And if you have a home garden or container garden, there’s no better way to get rich, nutritious compost for your plants.
The hardest part of maintaining a healthy worm bin is keeping it balanced. And like many people, that’s where I made the most mistakes early on.
I set up my first bin with 500 worms. I fed them daily, and it didn’t take long before the bin was emitting foul odors and swarming with fruit flies. Opening the lid was an exercise in gag reflex control, and I was ready to dump the entire bin in the backyard and be done with it.
My mistake was a common one: I added more food than the worms could possibly eat. The food rotted before the worms could get to it, and moisture quickly overloaded the bedding.
That’s why it’s crucial to go slowly in the beginning and only add small amounts of food scraps until you get a sense of how much your worms are eating each week. When a worm bin is in balance, it’s fascinating to see how efficient the worms are at turning waste into valuable compost.
What questions do you have about vermicomposting? Are you interested in setting up a worm bin?