I'm asking a few questions in getting my vermicomposter started. I'm using a 100gal Rubbermaid horse water tank. enter image description here

I'd like to know how deep the bedding should be when I start it and how many worms I need to get it started. I have access to shredded paper from work and I've been saving up scraps of paper and card board at home. I'll buy a couple of bags of garden soil from Home Depot and mix that together for the basic bedding, adding a little sand for digestion.

My plan is to start it shallow and gradually add material till it's full over the year. That way, they can keep rising and digesting and I'll end up with a lot of worm castings for my garden in the spring. I just don't know how deep I should start it and how many worms I need.

I found a site called Uncle Jim's worms, they have the red wiggler composting worms and will sell you boxes of 500, 1000, and 2000 worms. I want to start with the 500 and I really think that's too many since I'll start shallow. They sell the red wrigglers and the European night crawlers. I'm really not sure how these differ from the ones sold for fish bait and wonder if I could just buy some of those to start small and save on shipping. Anyway, if you guys could help me out on how deep to start it and how many worms it would take to get it started, that'd be great? Thanks.

  • 1
    Possible duplicate of How do I turn a plastic stock tank into a vermicomposter?
    – nilon
    Oct 12, 2016 at 16:05
  • I'd disagree that it's a duplicate. I posted both of them. The first one I'm asking how to physically turn a tank into a vermicomposting bin. Including how much ventilation and other questions about the actual bin. This one is asking about starting the bin and how many worms should go into it. I think those are two separate questions that cover step 1 and step 2 of starting a bin.
    – Dalton
    Oct 14, 2016 at 3:33
  • notice that your title here says "how many worms to start?". Perhaps you could edit both titles and other details to clarify your more than valid response. You could even use the info in past comment: step 1, step 2. Cheers.
    – nilon
    Oct 14, 2016 at 11:25

2 Answers 2


I've been vermicomposting for just over a year and I purchased from Uncle Jim's. I'd go with 1 lb or about 1,000 to start. The bedding only needs a few inches. If your food is really wet then maybe a little more (lots of melons). Also, I would strongly recommend:

  • Doing a compartmentalized food program rather than layers. I've found it's a pain to get the worms out of the compost. If you feed on one side wait and then on the other side. Then the worms will follow the food and leave the compost behind. Then you can harvest with ease.
  • I don't drill holes in my Rubbermaid. I did initially but if I just watch the moisture levels by the types of food I'm adding and keep it moist (not wet) by adding paper or water as needed it works much better than having that nasty leachate sitting in another container.
  • I don't feed my worms a lot and they're fine. One thing that is hard to deal with when starting is the desire for constant attention to the worms. Someone said worms thrive on benign neglect and it's pretty true. Just feed them and cover them and let them do their job.
  • I would add screen to your lid and close it. If you close your container tight you will end up with suffocated worms trying to get out. (And not eating your food). That's my experience and what's working for me. I think it's pretty fun so have a good time with it.

I don't want to discourage you from this plan, but I think the proposed container will pose a few challenges.

You will need to cover this to keep the worms from leaving and to keep animals from getting in and feasting.

You will definitely need to make accommodations for gas exchange. Drill holes in the side or don't let it get to densely packed or too deep. But no matter what you do, the bottom will get very dense as it fills with damp worm castings.

Harvesting the castings from this will also be more difficult that with smaller containers or different designs, but you might make it easier by using a screen divider so that you can dig out half while leaving the other half intact.

You can easily start with 12" of shredded cardboard (The Amazon Basics 12 sheet shredder has worked for us for several years). You'd maybe a 2 gallons of soil for the grit and 2 gallons of fresh, high quality compost for the microorganisms. Refrain from putting much kitchen waste in there for a while, and then slowly increase the amount you put in as long as they are keeping up.

You want red wigglers for vermicomposting. The night crawlers dig deep into the ground and only surface to nibble. The red wigglers live in the "food" layer that you are trying to break down.

As for how many worms to put in, we had some 24" x 48" x 24" deep flow-through vermbins built for clients, and were told that 5 lbs. of red wigglers (about 4,000 - 5,000) would not be overkill. But we needed to get things going quickly. If you can wait, then you could start out smaller. But I'd definitely think you'd want more than 500.

  • Thanks for the suggestions. I do have a cover to go on it. I plan to use a left over piece of thin siding material. It'll be easy to move. I can lay it on top and put a weight on it. It's been warped by the rain, so it'll let some air in around the edges. As for dumping it, I plan to use the tractor's front end loader to move or dump it onto a tarp when I need to sift it. Do you have a rough guesstimate of how many holes of what size I'd need to have enough gas exchange without drilling so many holes it weakens the container, destroys my bits, or lets it dry out to fast?
    – Dalton
    Jul 27, 2015 at 13:32
  • @Dalton - It's hard to say about the holes. I like the idea about the front end loader. in smaller verm-bins people will put in a screen wall dividing the container in two. When time to harvest, they feed only 1 side for a few weeks and the worms all move to that side. Then they dig out the other side and fill it in with new shredded cardboard. That way the worms pretty much stay put.
    – That Idiot
    Jul 27, 2015 at 19:11
  • @ThatIdiot I do that but without a screen. Anything worms that get caught just go in the garden.
    – Dano0430
    Jul 27, 2015 at 20:20
  • 1
    @ThatIdiot I am seriously considering your idea. Not necessarily for easy of getting the worms out, but more for the fact that if I empty it and start over, I'll have way too many worms for that amount of bedding. However, if I do it your way, then I'll always have the correct amount of bedding. Also, like Dano0430 said, I probably won't collect every single worm. I've seen some people say they spend hours picking over the dirt, then let the casting sit for a few weeks and do it again to get the newly hatched. I will probably just let those improve the garden and let the others multiply.
    – Dalton
    Jul 27, 2015 at 20:27

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