Some questions from Vadim:
I’ve built a flow through worm bin and got the habitat established. The system has been functioning for about 2.5 month now. If I dig a little into the bedding material, I can see good population of red worms evenly distributed throughout the bin, fair amount of worm castings and mixture of bedding material and some food I’ve been feeding them.
Here are the questions I have:
1. When I add more food for worms (mostly vegetable food scraps, etc.), I try to bury them under the bedding material. Is this OK, or should I just add them to the top only without mixing?
2. How much should I feed the worms? I try to add food only occasionally, since I can still see come food that is not fully digested. Do I need to wait until all of the old food is gone, or just add new material and let the worms feed at will. After reading various posts, I do not want to overfeed them, but I want to make sure they have enough food and encourage the population to increase.
3. The winter is coming and I plan to move the bin into an unheated shed. We don’t get too severe frosts here (South-Eastern Washington State), but I wonder if that will be enough to get the population through the winter. Anything else I need to do to help them along?
1) Burying food wastes is always going to be the best approach. This exposes the materials to more microbes, encourages the worms to feed sooner, and helps to avoid invasion from flying pests like fruit flies (or helps to suppress them if they are already in the material). A good strategy is to always keep a really thick layer of absorbent bedding over top of the main composting zone. This way you will always have lots of bedding for cover and to mix in with the food. It also helps to keep the upper zone fairly dry, thus discouraging any worm roaming.
You should still aim to spread the food out in thin layers, though. Rather than depositing the material in small depressions, create longer, shallow troughs so you’re not concentrating too much food in one area. As always, any optimization steps you can take (eg. chopping/grinding, freezing/cooking, mixing with “living material” etc) will assist the worms as well and are highly recommended.
2) Your feeding approach also sounds good. My philosophy is “let the worms be your guide” when trying to figure out how much to feed. When you feed in moderation, along with bedding materials, it is hard to go wrong. As for undigested food – it’s important to remember that not all food wastes are created equal – some are a LOT more resistant than others. The optimization strategies mentioned above can definitely help to level the playing field (especially if you can grind/chop really finely) as far as processing times go. If you are setting up say 3 or 4 food trenches in the bin, and staggering the food additions for each (perhaps adding new food every 4 or 5 days), by the time you get back to the first trench most of the food should be consumed. If not, just leave it longer. Low to moderate feeding + bedding will ensure that the population increases (assuming your bin is not already overcrowded).
3) If winter temps in your region don’t get too far below the freezing mark you should be OK keeping the system in the shed. If you know it’s going to be a lot colder than normal on a particular night, you may simply want to sit the bin on a heating pad of some sort (a mat for keeping seedlings warm, for example). Here are some other posts that may offer some ideas as well:
Heating a Small Worm Bin in the Winter
More on Small Winter Worm Bins
Winter Worm Bin Heating – A Novel (and Festive?) Approach
It’s important to mention that vermicomposting systems slow down a LOT when temps are low, so you should expect to feed the system a lot less. You literally might only need to feed the bin a few times all winter long – but as always, simply feed based on the response from the worms (if they are consuming everything, add more – if not, hold off).
Hope this helps!