Learn What Size Vermicomposting System (Worm Farm) You Need to Compost Kitchen Scraps
How to Conduct a Family Food Waste Audit to be Sure your Worm Bin Fits your Family’s Needs
Worm composting (Vermicomposting) is a form of composting in which you feed your vegetable food scraps to a specific type of earthworm called red wigglers (scientific name: Eisenia Fetida).
How many composting worms do you need? This article will teach you how to measure your food waste, calculate how many composting worms you need, and determine what size worm bin you should use to compost all your food scraps.
How much food waste does your family produce?
Before you can calculate how many composting worms you need, you must track the average amount of veggie food waste that you or your family creates. Below you will find simple instructions for how to track food waste and conduct a family food waste audit.
- Collect a day’s worth of vegetable food waste that could have been fed to your
worm farm. - Be sure to only collect the types of food waste that worms can eat. For more on this, read Feeding Your Worms
- At the end of the collection day, place all veggies scraps in a plastic bag and weigh it. A small kitchen scale or fish scale works well.
- Repeat each day for one week, then average the results together.
- You now have your daily average food waste.
How many red worms (composting worms) will it take to eat your average daily household food waste?
- Amazingly, red wiggler composting worms eat roughly half their weight every day!
- So, if your daily average food waste is 2 lbs, you will need roughly 4 lbs of composting worms to eat that amount each day.
- In this scenario, 4 lbs of worms is your optimal worm composting herd.
What size worm bin do you need to house your optimal worm composting herd?
- Assuming that temperature and moisture conditions are ideal and there is plenty for a worm population to eat, your worm population will expand to the size of its habitat (worm bin and worm bin bedding).
- Composting worms feed in the top inch of worm bedding so the next step is to calculate how many square feet you need on the surface of your worm bin.
- One pound of red wigglers for one square foot of surface area in a worm farm is a
good, healthy ratio (1:1). - So, if your optimal worm herd it 4 lbs, you will need a worm farm with at least 4 square feet of surface area.
- Many plastic storage bins fit this size and make excellent worm farms. For more on setting up a very simple starter worm bin using a plastic storage tote read: Make Your Own Simple Worm Bin
- If you need a larger worm composting herd, you will also need a larger worm composting container to hold the worms. For instructions on building your own custom worm composting container read: How to Make a Homemade Worm Composting Container
How many red worms are in a pound?
Since all of our calculations are based on weight, you don’t actually need to know how many worms are in a pound. However, just because it is fun to know roughly how many worms are in your worm herd: most worm composters use the estimate of 1000 red wiggler worms in one pound. Therefore, if you have 4 lbs of composting worms in your vermicompost bin, that means you have around 4,000 worms working for you!
How many composting worms should I start with?
In our example so far, you need to have a total of 4 lbs of composting worms to eat all the food scraps that your family produces. To get up to 4 lbs of red worms you can do one of two things:
- Buy 4 lbs of composting worms. This is the simplest but also the most expensive way to reach your optimum worm herd.
- Grow some worms. Another approach is to start your worm farm with 1 lb of worms and let them reproduce. This is a slower approach but it will save you money.
Now that you know how many composting worms you need to meet the needs of your family, you are ready to Build your Worm Composting Container or Buy your Worms!
If you found this article helpful, please share it with a friend. Thanks! Happy worm farming.
