Winter Worm Composting – 02-09-09

Winter Worm Bed
My dad surveys temperatures in the winter worm bed

Good news on the winter worm composting front!

I was able to get over to my dad’s place on Friday afternoon to see how things were coming along. It was my first visit since adding a large amount of manure (and more straw) to the system, and I was very eager to see if the bed had warmed up at all. As you may recall, the bed wasn’t doing too badly by the time I got around to adding the manure – temperatures in the middle of the pile were in the 15 C (59 F) range.

Compost Thermometer

Temperatures have certainly climbed since then! I am very happy to report that throughout much of the bed temperatures are 20 C (68 F) or higher (see picture to right).

What impressed me even more than the maximum temperatures, was the fact that the warmth was so widespread. On one side, just in from the wall, there still seems to be a really cold zone (just over the freezing mark), but the rest of the bed is averaging 15 C (59 F) or higher. Surprisingly, I found some really warm zones only a couple inches in from the back wall!

Given the optimal vermicomposting temps in much of the bed, I was naturally curious to see what the worms were up to down below. I was pleasantly surprised to find lots of them up in the manure layer, just under the straw.

Red Wiggler Worm
Healthy looking Red Worm (Eisenia fetida) from the winter worm bed

There seems to be a lot of young/small worms in the upper zone, but I did find some spots with a fair number of decent sized worms as well. This small worm dominance didn’t surprise me too much – in my experience, the larger worms often tend to concentrate themselves further down in a worm bed.

In other (good) news…

It looks like we (or more accurately, my technically-gifted brother) managed to get the weather station system – mentioned in my second winter worm compost post – working as a remote temperature probe!

Burying Temperature Probe
Remote Weather Station Sensor Gets Buried in the Pile

We buried the receiver in a zone that should provide us with a rough estimate of the average bed temp – that is to say, it’s not quite in the middle of the heap, and it isn’t buried very deep either. It started in the 14-15 C (57-59 F) range just after being buried, and according to my dad’s latest report it is now up in the 20 C (68 F) range.

We’ve clearly reached an interesting stage in our winter worm bed experiment. Believe it or not, the challenge will now involve trying to maintain ideal temps throughout much of the bed, without having any zones overheating too seriously. What’s really nice about this particular system, as compared to my previous (much smaller) winter composting bin, is that the worms should be able to move away from overheating zones quite easily.

Weather will likely play an important role on both sides of the coin (cooling/heating) from here on out. It was mild on the weekend, and this week we’re are supposed to have a couple days WELL above freezing – but I have little doubt that we still have plenty of winter weather ahead of us. It will definitely be interesting to see how significantly the temperature in the system changes over the next few weeks.

As it stands, I’d say this project has been a resounding success! Previously, this would have been right around the time that I was forced to give up on my winter worm bins, since temps were continuing to drop.
In this case, we really got off to a slow start (which in hindsight might have actually helped us), but things have been improving ever since. As it stands, it looks like there’s a very good chance I’ll be able to start harvesting worms from this bed before the end of the month!

I’ll certainly keep you posted!

Previous Winter Worm Composting Posts

Winter Composting Extravaganza 2.0
Winter Worm Composting – 12-08-08
Winter Worm Composting – 12-15-08
Winter Worm Composting – 12-30-08
Winter Worm Composting – 01-23-09

**Want Even More Fun With Worms? Sign Up for the RWC E-mail List Today!**
Previous Post

Worm Inn Journal – 02-10-09

Next Post

Setting up a nightcrawler bin


    • Rich A.
    • February 9, 2009

    Will cocoons survive prolonged freezing temperatures in your experience?

    • Bentley
    • February 9, 2009

    Hi Rich,
    If they are directly exposed to temps well below the freezing mark for an extended period, it is safe to say that worm cocoons will likely be destroyed. If, on the other hand, they are buried down in a large amount of material (perhaps with snow over top), they should be able to withstand very cold winter temps. So, for example, if you had red worms in your backyard composter, while most of the worms would likely die during the winter, you would almost certainly have a new generation of babies hatching out once warmer temps arrived.

    Cocoons are definitely more tolerant than the worms themselves.


  1. You convinced me, Im going to try it next year in Maine.

    • Bentley
    • February 10, 2009

    Glad to hear! Hope you keep me posted on that.

    • Jbushy
    • September 8, 2009

    thanks very much for the updates on winter composting/bins. I began my first bin 8×5, this past spring and have been worried all along about what to do this winter. I live in Michigan the land of snow and crappy long winters. To date the bin has been extremely succesful. My father in-law is a dairy farmer so I have unlimited supply of moo-dung which sounds like a good top layer and food source for the winter…as long as I don’t use too much. In any case, thanks again and I will be checking in for your updates in particular. Happy wormin’!

    • Bentley
    • September 10, 2009

    Yeah, ‘moo-dung’ (haha) and straw would make a great mix. Anyway, do let me know how you make out this winter. I will certainly be writing more about this again once the snow starts to fly.

Leave a Reply

Your email address will not be published.

Get Your Free Vermicomposting Guide!

* Join the Red Worm Composting E-Mail List Today *