How to separate worms from worm castings

by Chris

Bathtubs used as a worm farm

Bathtubs used as a worm farm

Hello, as you can see I am using baths as a 'container' for my worm farm.

How do I seperate the worms from the worm castings in this situation? If I expose the worms to sunlight they retreat only a few centimetres below the surface making it a long exercise to remove the castings. If I place he food horse manure at one end of the bath not all the worms move to the food and the same problem happens.

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Aug 22, 2016
Different ways to separate worms from worm castings
by: Stephan

Hello Chris,

we have used bath tubs as well as worm farms and found that they really work well. Your set up looks good and I am sure the worms are doing great inside their bins.

When it comes down to harvesting worm castings there are are a few ways that have become popular with most worm composting enthusiasts. The easiest way being obviously the one where worms move from a worm bin up into the next bin situated above it. This method is obviously not working with single bins like a bath. There are 2 other methods worm castings can be harvested relativly quickly from single worm bins.

1. A lot of commercial worm farmers make use of a worm harvesting machine. They work very well. The worm castings containing the worms are thrown into the opening on one side and the castings are falling through the screen into bins below while the worms stay inside the machine and can be picked up at the end of it after a few minutes. You can see the model that we build ourselves at the following Url:

If you don´t have access to a machine like that it would probably be best if you use the following way to harvest the castings from your bath tub worm farms.

Stop feeding the worms for a while till they have finished nearly all the food in their bin.

1 to 2 days before you want to harvest the castings place a layer of worm food like horse manure or any other organic material that can be used as worm food on top ofd the worm bedding in your worm bin and cover it with plastic sheeting to keep the surface of the worm bin dark. This way you will encourage the worms to crawl right to the surface of the bin to feed on the new food.

The best time to harvest your castings is usually early in the morning between 6 to 9am before the heat of the day. So a day or 2 after you added the new food remove all the remaining food as well as a layer of about 10cm / 4 inches of worm castings below it. This way you should be able to remove nearly all the worms from your worm farm. There are nearly always a few worms that stay behind in the bin but the loss of a few worms can swiftly be compensated by the breeding action of the mature worms in your bin.

More detailed information about worm castings can be found at the following Url´s:

I wish you all the best for your worm composting project.

Kind regards

Stephan Kloppert
Author of "How to start a profitable worm business on a shoestring budget"

Editor of ""

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