How To Harvest Worm Castings Using A Flow Through Bin

harvest worm castings demo side view

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I’ve tried a number of different methods to raise worms and I’m sold on the flow through bin.  In the beginning, all of the worms died and there were no castings to harvest.  What a bummer.  Now I don’t have those problems anymore.  Not since I switched to a flow through bin.  I’ll show you how easy it is to harvest worm castings using this simple design.

Principles Of The Design

A flow through bin is very simple. It’s an open container and you fill all of the worm food from the top. This is different from a lot of the other designs that you see on the market. Most of the designs I’ve seen stack one on top of the other and then you wait for  the worms to migrate upwards. I don’t really like these and it takes forever to get your castings.  You are also required to do a lot of lifting to move your layers over and over.  I’m more of an automatic type person and prefer to let gravity to the heavy lifting.

For these reasons, I’ve switched to a flow through worm bin for easy harvesting of castings, best health, and easiest maintenance.

Tools Required

You only need a  few simple things to harvest worm castings in this way. I like to use a three-pronged tine to work the castings out from in between my rails, which are at the bottom.  The rails hold the castings and the worms in place very effectively.  You can pick one of these 3 prong tines cheap at your local home store for just a few bucks.

Next, you’re going to need some sort of container to put your castings in. Just grab anything you have find like a plastic bin.   I just happen to have a hotel pan works pretty well so that’s what I used.

Start Harvesting

The great thing about this is you can just harvest only the amount that you need. One thing to keep in mind though, is that you don’t want to harvest to the point that you reach the worms. Composting worms congregate in the upper few inches of your bin so that’s a good indication of where they would be. However, I have seen a few of stragglers deeper so if you start seeing worms when you’re harvesting castings, then stop.

Check out this quick video and I’ll show you how I did it.  Oh, if you want to get the same worms that I have, then you can Order Them Here.  Note, if you do buy from Uncle Jim’s, then I will receive a small commission.  I’d really appreciate it if you would buy through my links.  It helps me to support this site and costs you nothing extra.  Thank you.


So if you are looking for a way to reduce mess and harvest only the castings that you need that day, then consider a flow through worm bin.  Castings are retrieved from the bottom without hurting the worms.

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