You're on the right track there but I don't think you can screen for worm cocoons/eggs unless you are going for really dry and broken up vermicompost. It may be more efficient to screen out larger bits + cocoons into a "finishing bin" where you can allow the cocoons to hatch out. You could then periodically screen the "finishing bin" contents to get the last few worms. You'd have to do this often enough to ensure that hatched worms do not start to breed in the finishing bin.

You might be interested in these photos:

http://home-and-garden.webshots.com/album/131681468JcMKOK

Well it is not practical if you have to screen every little bit of the worm cocoons.

We tried it in our farm, it just take too much effort.

So we figure out that the best way is to grow the worms as soon as possible to compensate for the lost cocoons.

Fed them with lotsa protein, but ensure not prtein poisoning.

It work for our farm

trying to get every last cocoon is probably an exercise in futility unless you enjoy manual hand sorting of compost. not for me personally. i think that if you have a system where worms are actively multiplying and are given time to do so, then you can live with a few lost cocoons.

have you looked into a flow through system for composting? if the volume of material is deep enough and spends enough time going through the system to hatch out most cocoons before falling through the bottom then you can be reasonably sure that many or most cocoons have hatched out and some losses can be seen as acceptable losses.

Hi there Wildgoat,

I'm currently experimenting with expanded steel mesh as a seive for my compost bin (I have a large population of EF's that do a great job in there, and I'd like to save as many as possible when I dump the bin (250 liters / 65 gallons). This stuff seems stronger than plain wire mesh (also, couldn't find any between 1/4 and 1/8" grid), so it might last for a while.

My plan is to use a frame 2' x 1' covered on one side by 6mm expanded mesh, forming a seive tray. One shovel full at a time, I'll dump into the seive, quick shake (over wheel barrow) and what remains (should be large compost plus good amount of worms) will get dumped into the now empty compost bin as the basis for starting the next batch.

The fines in my wheel barrow might be another trial. I might fill say 5 x 10 gallon totes with some, and wait 5-8 weeks for cocoon hatching, and pass it through the same seive again (or maybe finer??).

By this stage, I think I may have saved at least enough worms to be worth while (lol I hope).

I'll let you all know how it goes (maybe stage 1 in the next week or 2). I have already made the seive (cost $AU6.00 for the mesh)

Cheers

Here is a link that might be useful: Expanded mesh(s)

Thanks for that info! I'd love to hear about how it works out for you!!

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I'm in the middle of establishing a new bin. I have a different method of separating. Instead of sifting out the castings from the worms, I'm sifting out the worms from the castings. Here's what I do: I have two plastic containers the same size, one being shallow and the other deeper. The bottom (deeper) one is filled with damp shredded cardboard and the shallower one which has 1/4" holes drilled all over its base, rests on top. The top one is filled with castings and exposed to sunlight or a light bulb (with a reflector). As soon as the strong light comes on, the worms move quickly downwards through the holes into the shredded cardboard. As I poke around and expose more worms to the light they too move downwards so that within 5 or 10 minutes, the top container is worm-free. I then dump out the castings (which contain the cocoons plus any tiny worms that didn't go down) into a larger plastic container which will eventually go back into the original bin for another month or two to allow the cocoons to hatch. I will resift in 2-3 week intervals to catch the worms as they grow but before they reach sexual maturity and start producing more cocoons. After sifting out as many worms as possible, I'm left with a mass of worms in the lower container (almost completely free of castings) which I then add to my new bin.

Shaul

Shaul;

This sounds like a great idea. I assume the containers should be tapered so that the top one will fit into the bottom. I will be looking around for suitable containers. My oldest bin, started about the middle of Dec. last year is getting close to harvest time.

Dave Nelson

Hi Dave;
The two containers don't have to completely fit inside each other, just that the bottom one is filled with the damp shredded cardboard and the upper one rests on top. There should be enough bedding so that the worms go through the holes and straight into it without any air space in between. If you had the space you could set up a number of these at one time, each with its own overhead light bulb and reflector (the reflector increases the light and heat thereby allowing you to use a lower-wattage bulb like a 40w or 60w instead of a 100w and still get the same effect).

Shaul

I found good containers. I went to one of the local bakeries where they do their work on premises and bought 2 of the buckets that their shortening come in. They sell them for 1 dollar apiece, all cleaned and ready to go. I'll drill the holes tonight after supper.

Dave

The holes are drilled and the bottom bucket is filled with shredded cardboard and newsprint. I'm anxious to get started but I'm going to have to be patient. I just inspected the oldest bin and the worm population looks good but there is still a lot of undigested material visible. I think it calls for another week or ten days.

Dave Nelson

This is a follow-up to my previous posts in this same thread. As I said, I'm in the middle of moving my worms to a new bin. My idea of sifting the worms from the castings is viable, it definitely works. But it works best in sunlight, the stronger the better. Optimal depth in the upper container is 1"-2" in order to expose the maximum number of worms to the strong sunlight. This way, they rush down through the holes to get away from the light.
It also works with light bulbs, preferably 100w or better. The advantage to light bulbs is, you can work indoors or at night (a reflector will help intensify the light and heat). Again, the more containers you have to work with, the more worms you can process at once; and every couple hours you can empty the bottom containers which should contain a mass of clean worms (95% clean of castings); which can then be added to the new bin.
I started my bin just over 4 months ago with around 100 worms, I now have well over 1,000. True,the sifting process is slow (more or larger containers (more surface area)would definitely help); but the reality of getting clean worms (95% clean of castings) is definitely worth the wait.

Shaul

I have two questions.
1) If you are using plastic bins, and drill your holes, do the rough edges tend to puncture or shred the worms as they pass thru, especially in a hurry?

2) do you seed the new bed with any of the old worm compost?

Thanks. I have been really thinking on how to 'harvest' my worm compost for a few weeks now, as my ten gallon bin is getting full and I would like to add new bedding for them, removing old worm compost, and I wouldn't mind finding out about how many worms I actually have.

This is a definate idea on how to do this safely for the worms. I appreciate it!
Gina

Instead of a bin on top layer, and more flexible because it will fit into any size of new bin, try a black plastic bag with loads of holes punched in it (A school hole punch is good) laid on op f new bedding. Then place old bedding on top, hand remove large undigested material and expose to light.

Hi Gina;

Actually, your first question was a major concern of mine, but the worms seem to be doing ok. I think it's important that the upper container (with the holes) is right on top of the damp shredded cardboard (or other bedding), with no air spaces in between, so that the worms aren't hanging over the edge of the holes as they move downward into the bedding. This way they just sort of glide through the holes straight into the bedding.
When you think of what they have to deal with in the ground or a compost pile: twigs, sticks, thorns and rocks, this isn't too much different. It's always a good idea to run your hands over the holes on both sides, checking for sharp edges or other imperfections. A small round metal file might be put to good use in smoothing away any problems.

On question #2, no I don't seed the new bin. I thought the whole idea was to separate the castings from the worms. Of course there is a small amount of castings that are dragged in with the worms but the amount is negligible.

Shaul

Hi Cath;

I know about the plastic sheet method, actually I developed my idea from it; but if everyone had been 100% satisfied with the idea of piling the castings in cones (and then scraping away the upper levels as the worms burrowed deeper into the stuff), then we would never have gotten this far.
Here's a quote: "There is no wrong way to harvest a worm bin, many methods and techniques exist". Actually you and I both use the same system to accomplish the same thing, only in different ways; and yes of course it is possible to use only the upper hole-y container straight on top of the new bin.
With my system I could reuse my container 500 times without any appreciable wear and tear. Also, I'm not limited by the surface area of the bin but rather by the amount of containers available to me. Now let's say I had 10 containers, each one half the size (width x length) of the average (Rubbermaid-type) worm bin. With 2 containers per bin, that means that I could process 5 times the amount of castings as you, in the same amount of time. That's an impressive difference. Of course initially, it's a lot of work drilling out all the holes, etc. but the result is something re-usable, endless times.

The important thing here is that whatever system works for you, you should go with.

Shaul