Worm Composting Basics: A Summary Guide to Getting Started
In this post we'll walk through the basic steps to getting started composting with worms. 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 use, how to set-up your first bin, what to feed your new squiggly friends, and more!
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 or vermicompost). This process is the result of 500 million years of evolution - the live worms take in nutrient-rich material and "poop" out even richer material with high microbial activity. These 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?
There are a variety of live worms that can be used to compost at home or in the classroom, but most people use compost worms (e.g., Eisenia Fetida, Eisenia Hortensis, Perionyx Excavatus, etc) or nightcrawlers (African or European). Compost worms are voracious eaters and can survive and thrive in a broader range of conditions than their nightcrawler cousins, so they are the preferred worms for composting. 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 are voracious eaters and can consume 1/3 to 1/2 their weight in a few days!
What Do You Need to Start a Worm Bin
Worm bins are easy to set-up for your home or classroom. You can order a worm bin or worm farm kit, or simply start with a 5-15 gallon plastic storage bin. The bins don't need to be too deep as compost worms are surface dwellers and live in the top 4-6 inches of the soil.
In addition to the bin, we recommend:
- Bedding: A mix of topsoil or peat moss and shredded newspaper or cardboard to use as bedding for the worms. 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 12 or more inches so the worms have somewhere to go if temperatures get too hot or too cold for them.
- Live worms (e.g., compost worms)
- A cover for the 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 then a more secure lid will be needed. Too much rain can drown worms so the lid should not allow water in and should have drain holes in the bottom if it will be in an area where it can be rained on.
How Many Worms Should You Buy?
Given the excitement around setting up your first worm compost bin, there's a tendency to buy more worms than you actually need. We recommend starting with 1 pound of live compost worms for every square foot of bin space you have. You can always add more later after you get comfortable caring for the worms!
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 in a few days to your doorstep. We offer live compost worms in variety of order sizes at Brothers Worm Farm.
Setting Up Your First Worm Bin
Once you have the bin, bedding, and live worms, setting up the bin is a breeze:
Step 1: Gently wet the bedding )e.g., soil, shredded cardboard, etc). The bedding should not be soaked in water as that will result in water accumulating at the bottom of the bin (which can lead to bin conditions that harm the worms). A good rule of thumb is that when a handful of the bedding is squeezed, 1-2 drops 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 worms and the bedding they were packed with in the cardboard bedding.
Step 4: Place the cardboard or newspaper cover over the worms and place the bin in an area with moderate temperatures and away from the sun. If your 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 5: The following day after the worms have acclimated begin feeding them.
What to Feed your Compost Worms
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 not 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)
- Pumpkin and squash
- Pulp from juicers (avoid citrus)
- 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)
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)
- Citrus fruits
- "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
How to Feed Your Compost Worms
The key to feeding your 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 1/5 to 1/4 pound 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 to 1/2 of their weight. So if you purchased 2 pounds of worms, feed them 2/3 to 1 pound of food at a time.
Watering Your Worm Bin
Similar to over-feeding, there is tendency to over-water worm bins when getting started. 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.
- Watering your bin around once 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.
Caring for Your Worm Bin
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 maintaining your bin.
Here's a quick checklist of to do's to ensure your compost worms stay healthy and happy:
- Feed 1/4 to 1/2 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 - it will start to look like wet dirt and should have the look of felt from a pool table - you will want to mix in a little carbon (e.g., shredded cardboard or shredded newspaper) directly with the fruits and vegetables you are feeding them. Aim for a ratio of 90% food and 10% carbon.
That's really all there is to it. 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.
Thanks for reading! If you have any questions or comments, shoot us an email or check the other tips and how to articles on our blog. Happy farming!!