Worm Composting 101: The Complete Guide to Starting a Worm Bin (with Photos!) (2024)
In this post we'll walk through the basics of composting with worms and provide the steps for starting a worm bin. If you're new to worm composting this guide will cover all you need to know to get started, including:
- what worm composting is,
- the best type of compost worms to buy,
- how to start your first worm bin,
- worm bedding and what to feed your new squiggly friends
- Frequently Asked Questions (FAQs)
- and more!
Worm Composting for Beginners - What is Worm Composting?
Composting with worms means using live compost worms to process organic waste like food scraps, leaves, cardboard, manure and other material. As compost worms consume the organic matter, their digestive process turns the waste into worm castings (e.g., vermicast, vermicompost, or worm poop), a nutrient rich material helps plants thrive.
Red wigglers in a mix of compost and worm castings
This process is the result of 500 million years of evolution - the compost worms take in nutrient-rich material and "poop" out even richer material that helps plants grow bigger, faster, and stronger.
These worm castings do such a great job helping plants thrive that they are valuable soil amendments used by organic farmers, vineyards, greenhouses, and the cannabis industry.
What are the Best Compost Worms to Buy?
There are a variety of live compost worms that can be used for worm composting at home or in the classroom, but most people use compost worms (e.g., Eisenia Fetida, Eisenia Hortensis, Perionyx Excavatus) or nightcrawlers (African or European).
Red wigglers are a great compost worm for beginner and experienced worm composters!
Compost worms are usually reddish brown in color, grow to 2-4 inches in length, and sometimes have a yellow tip on their tail end. They are smaller than nightcrawlers but can consume 1/3 to 1/2 their weight in a few days!
Worm Composting for Beginners: What You Need to Get Started
Worm composting is easy to set-up in your home, classroom, or outdoors in your lawn or garden. Beginners can order a worm composting bin or worm farm kit, or simply start with a 5-15 gallon plastic storage bin.
If you are interested in purchasing a worm bin, check out our detailed review of the best worm compost bins to buy.
Also, it's important to think through where to place your worm bin (inside our out). If you are on the fence about where to keep your worm bin, we wrote a guide on what to consider and mistakes to avoid when deciding where to keep your bin.
Worm compost bins can be bought online or built at home.
The bins don't need to be too deep as red wigglers are surface dwellers and live in the top 3-4 inches of the soil.
In addition to the bin, you will need:
- Worm Bedding: Worms love compost or manure, but if you don't have any handy you can buy worm bedding for your bin. We sell a specialized worm bedding mix or you can build your own with a mix of topsoil, coconut coir, or peat moss AND shredded newspaper or cardboard. A good ratio is 75% top soil/peat moss and 25% shredded newspaper or cardboard. You'll need enough to fill the bottom of your bin to a height of ~4 inches. If your bin will be outside then we recommend a bedding depth of 24 or more inches so the worms have room to dig if temperatures get too hot or too cold for them.
- Live compost worms (we have a variety of sizes and options in our shop)
- A cover for the worm compost bin (NOTE - worms need air so this should not be an airtight lid.) A piece of cardboard or newspaper works fine for an indoor bin. If your bin is outside, it will need to be under a covered porch or patio (too much rain can drown worms).
How to Set-up Your Worm Composting Bin
Once you have the worm bin, worm bedding, and live compost worms, setting up the worm bin is a breeze:
Step 1: Gently wet the bedding (e.g., soil, shredded cardboard, etc). The bedding should not be soaked in water - a good rule of thumb is that when a handful of the bedding is squeezed, 1-2 drops of water wring out.
Step 2: Place the damp bedding in the bottom of the bin and spread it out evenly. It should cover to a height of 3-4 inches or so.
Step 3: Gently place the live compost worms and the bedding they were packed with in your worm compost bin.
Step 4: Place a small amount of food in the bin and sprinkle a little bedding over it (a cut-up banana works great to start and don't bury the food since compost worms eat on the surface!).
When starting out, we recommend a little more bedding (3-4 inches deep) and a little less food than pictured here!
Step 5: Place the cardboard or newspaper cover over the compost worms and place the bin in an area with moderate temperatures and away from the sun. If your worm bin is indoors, a pantry, closet, or garage works great. If outdoors, place in a shaded area away from the sun. Compost worms prefer temps of 65-85 degrees Fahrenheit.
Step 6: Check the bin once a day to verify the worms are acclimating and have started eating. Once the initial food is gone, feed the worms again.
Worm Composting Care Checklist
Once you've set-up your bin, bought your live compost worms online, and settled on a feeding and watering schedule, there's not a lot of work involved in worm composting.
At home I feed and water my worm bin once a week, but twice a week is a good benchmark to set when starting a worm bin.
Here's a quick checklist of to do's to ensure your compost worms stay healthy and happy:
- Feed the worms 1/3 of their weight and only feed after all food from the prior feeding has been processed.
- Verify the top of the bed is damp and there is no water accumulating on the bottom of the bin or in the base of the bin. Lightly mist the top of the bed if it is getting dry.
- As the bed begins to get fully processed (after ~6-8 weeks) - it will start to resemble wet coffee grounds and should have the look of felt from a pool table. This means that most of the bedding will be worm castings. Worms can't live in their poop for long, so at this point you will want to either start a new tray in your worm bin or add 2-3 inches of new bedding to the surface of the bin.
To add new worm bedding, mix carbon (e.g., shredded cardboard or shredded newspaper) and new bedding (aim for a ratio of 75% bedding and 25% carbon) and place it on the surface of the worm bin.
Remove any food before doing this step (or wait until the worms have eaten all of the food!).
Place new food on the surface of the new bedding and the worms will migrate up and begin eating again.
That's really all there is to it getting started worm composting. Compost worms don't require a lot of TLC once they are established in their new home, and as noted above they prefer quiet and solitude to do their work!
Worm Composting FAQs
Q: How Many Compost Worms Should You Buy?
Given the excitement around starting a worm bin, there's a tendency to buy more live compost worms than you actually need.
We recommend starting with 1 pound of live compost worms. You can always add more later after you get comfortable caring for the worms! Over time, a density of ~ 1 pound of compost worms per 2-3 feet of square footage in your bin is a good benchmark.
Q: Where Can I Buy Live Compost Worms?
Most compost worms are sold online, so it's easy to purchase them via the web and have worms delivered to you in a few days. We offer live compost worms for sale in a variety of order sizes at Brothers Worm Farm.
Q: How Deep Should Worm Bedding Be in the Worm Bin?
For compost worms (e.g., Red Wigglers), bedding only needs to be 3-4 inches deep since these worms live in the top few inches of soil. It's ok to have more bedding than this but the worms won't process the bedding (into castings) past the first few inches.
Nightcrawlers burrow deeper into the soil so worm bedding should be 8 to 12 inches if you have nightcrawlers.
Pro Tip: If your worm composting bin will be outside then we recommend a bedding depth of 18-24 or more inches so the worms have room to dig if surface temperatures get too hot or too cold for them.
For outdoor worm composting, give the worms 18-24 inches of worm bedding.
Q: What Should I Feed Compost Worms?
Compost worms are fantastic eaters and will eat just about anything. But there are foods that can harm them or lead to poor bin conditions, so it's important to stick to a few basics.
The "Go" List includes most raw/uncooked fruits and vegetables as well as the following items:
- Worms have a sweet tooth so most fruits are a great idea (just limit the amount of citrus). Compost worms love bananas, grapes, melon, pears, berries, peaches, apples, and avocado (but not the pit or rinds)
- Green leafy vegetables (e.g., romaine)
- Soft veggies like pumpkin and squash
- Pulp from juicers
- Crushed egg shells
- Coffee and tea grounds in small quantities (too many can lead to an acidic bed which can harm the worms)
- Shredded cardboard, egg cartons, and paper towels
- Most leaves (as long as they haven't been treated with pesticides or herbicides)
- Citrus fruits in small quantities
The "No Go" list for feeding worms includes:
- Dairy, cheese, and milk products
- Meat or other animal products
- Cooked foods (due to oil and salt content)
- "Spicy" foods like peppers, onions, garlic, and ginger
- Tomatoes or tomato sauce (it's too acidic for worms)
- Foods cooked with oils
- Foods high in salt content
For more on what, how much, and when to feed your compost worms, we wrote a Compost Worm Feeding Guide with tons of tips and info.
Q: How Do I Feed Compost Worms?
The key to feeding your compost worms is moderation. Over-feeding, along with temperature, is one of the easiest ways to quickly kill your worm population.
We recommend the following:
- For the first feeding, feed 1/5 to 1/4 of the weight of your worm population. For example, if you bought 1 pound of red wigglers, feed them 3-4 ounces of food scraps.
- Never feed your compost worms until all food from the prior feeding is consumed/processed.
- Don't bury the food! Compost worms are surface dwellers and will generally not eat food that is more than an inch or 2 below the surface.
- After the first feeding, feed the worms 1/3 of their weight. So if you purchased 2 pounds of worms, feed them 2/3 of a pound of food at a time.
- Worms should finish each feeding in 24-48 hours - if they do not then wait until the feeding is completed before adding more food, and remove older food after 4-5 days if the worms have not touched it.
Q: How Much Should I Water a Worm Composting Bin?
Similar to over-feeding, there is a tendency to over-water when getting started worm composting. This can lead to factors that are not beneficial to your worm population, or conditions that can outright kill the worms.
Worms need a damp, but not wet, environment to thrive. Here're a few rules to go by when watering your worm bin:
- Never pour water into a bin. This will lead to over-watering or inconsistent moisture throughout the bin. We've found a spray bottle or light mister works best.
- Water your bin with a light to moderate misting 1-2 times per week.
- Don't let water accumulate in the bottom of your bin. If water accumulates, this is a sign you are watering too much so adjust your watering schedule and amounts!
- Make sure the top inch or so of your bin is the most moist part of the bin. The bedding should get more dry as it goes to the bottom of the bin.
For a more on watering your compost bin, see our When, How Much, and How Often Guide to Watering Worm Composting Bins.
If you have any questions or comments, shoot us an email, read more about troubleshooting worm compost bins, or check the other worm composting tips and how to articles on our blog. Thanks for reading and happy farming!!