Most worm bins fail quietly. A hot week bakes the bedding, a cold snap stops the worms eating, scraps pile up and start to smell, and by the time you notice, half the worms are gone. My Worm Bin is a free worm bin diary and worm bin simulator that watches the weather where you live and tells you what your bin needs before it becomes a problem.
What the worm bin diary does for you
- Knows your weather. Tell us your town and where the bin sits: indoors, in a garage, in the shade or in the sun. We turn the local forecast into an estimate of the temperature inside your bin for the next nine days.
- Warns you before heat and frost. If the bin is heading above 32°C (90°F) or towards freezing, you get an alert the day before with simple steps to protect the worms.
- Reminds you of every task. Feeding, moisture checks, fresh bedding and harvest dates are worked out from your own diary, so the reminders match your bin, not a generic calendar.
- Simulates your worm population. From the worms you started with, your feedings and the temperatures your bin has had, the simulator estimates how many worms you have now, how much food they can handle this week and when the castings will be ready.
- Keeps your records. Every feeding, reading and harvest is saved in your worm bin diary. Download it as a CSV file any time.
How the worm bin simulator works
Red wigglers eat and breed fastest between about 18 and 26°C (64–79°F). Below 10°C (50°F) they slow right down, and near freezing they stop. The simulator follows your bin one day at a time from the date you started it. For each day it estimates the bin temperature from your local weather and the spot the bin sits in, works out how active the worms were, and grows the population towards what your bin can hold, which is roughly 10 kg of worms per square metre of floor (2 lb per square foot).
It also tracks the food you log. Worms process about a quarter of their body weight a day in good conditions, so if you feed more than they can eat, the simulator notices the leftovers building up and tells you to skip a feeding. If you weigh your worms or push a thermometer into the bedding and log the reading, the simulator uses your real numbers instead of its estimate, and it gets more accurate for your bin over time. That is why a worm bin diary with real readings beats any generic feeding chart.
Worm bin reminders that know when to stay quiet
Reminders arrive as one short morning email, in your own time zone. By default you only get one on days when something actually needs doing: a feeding is due, the moisture needs checking, or the weather is about to turn. You can switch to a weekly summary, or turn emails off and just check your dashboard. Every email has a one-click link to stop reminders.
The forecasts come from the Norwegian Meteorological Institute (MET Norway), which publishes free, high-quality forecasts for anywhere in the world. Your worm bin reminders are only as good as the weather behind them, so we refresh the forecast through the day.
Getting started takes two minutes
- Create a free account with your email address.
- Search for your town, and choose where the bin sits and what kind of bin it is.
- Enter roughly how many worms you started with (by weight) and the date you started.
- Open your dashboard: your tasks for this week, the forecast for your bin and your first population estimate are ready.
Questions about My Worm Bin
Is it really free?
Yes. The worm bin diary, the simulator and the reminders are all free. There is nothing to pay and nothing to install. It works in any browser on your phone or computer.
What do you do with my location?
We only use it to fetch your weather forecast. Your location is stored rounded to about 1 km, never shared, and you can change it or delete your account and all of your data whenever you like.
How accurate is the worm bin simulator?
It is an estimate, built from published figures for red wigglers and the conditions in your bin. Real bins vary, so treat the numbers as a guide. The more you log, especially worm weights and thermometer readings, the closer it gets to your bin.
Does it work for an indoor bin?
Yes. Indoor bins mostly follow your room temperature, so you will see fewer weather alerts, but feeding, moisture and harvest reminders work the same way. If you are new to worms, our guide to starting a worm bin and the free worm tools are good places to begin.