How Many Worms Do I Need?
Here is a question from Denise:
I watched you video on how to make a bin and I am excited to try this
new way of composting our kitchen leftovers. We easily have 1+ pounds
of scraps a day……what size rubbermaid bins would be good to start
with and how many pounds of worms……will the colony of worms grow
fast….and need to be moved to another bin? What is fast? months or
Those are good questions. I would say that with that amount of waste, you should probably start with at least two pounds of worms, assuming you want to deal with all that waste from the start (more on that in a minute). That being said, I should mention that this is in no way set-in-stone advice. Every worm bin is different, and there are a LOT of different variables at work here. Just for example – let’s say that you keep your bin in your garage where temperatures are quite cool (eg 50-60F). The processing speed of the system at these temperatures will definitely be much slower than they would be if the temperature was 75 F.
How you handle the waste is another important consideration. If you just throw it in fresh, with little or no chopping etc, having 5 lbs of worms in the system probably wouldn’t even help. Helping the worms/microbes along as much as possible is one of the keys of effective vermicomposting. Freezing/cooking/chopping/blending/aging etc are great ways to get things moving more quickly.
Another important consideration is the fact that worms will rarely be processing at their maximum efficiency right off the bat – generally, they’ll need some time to get used to their new system and settle in. As such, it is really important to be very conservative with your feeding early on, at least until it is clear they are consuming the food materials quickly. Basically it just comes down to letting the worms be your guides (rather than simply relying on guidelines provided by people like me – haha)
As for the size of bin you should use, let me share with you my personal favorite. I think the best all-around Rubbermaid bin is the ~ 12.5 Gal (24″ long x 16″ wide x 8.75″ deep) Roughneck tote. It is large enough to easily house up to 3 or 4 lbs of worms, yet it’s not so huge as to take up a lot of space in your house. I love the relatively shallow 8.75″ depth – this helps to ensure that the lower reaches of the tub don’t end up sloppy and anaerobic. I generally use these tubs without a lid (further helping to ensure good air flow), but not everyone is going to want to do this obviously.
If you put 1-2 lb of worms in a bin like this they will grow fast to take advantage of available space/resources (assuming they are taken care of), but the population growth will slow down once conditions become crowded for them. At this point, you can start up a new system, and simply move half of the contents over to this new bin -OR start up an outdoor system (eg. vermi-trench), give them away etc. Check out this post for ideas – What Do I Do With All My Extra Worms??.
Hope this helps!