Harvesting your castings is often the most difficult part of worm farming and where bin designs make a lot of the difference between easy harvesting and difficult harvesting.
For home use, the popular bins with the stackable trays are relatively easy when it comes to harvesting time. For these types you'll simply take the lowest tray, empty into a large plastic container or box for screening.
A common method to separate any stubborn worms still in the castings are to stack the castings in a tall pile while shining a small lamp or light on the pile. The worms don't like light and will move to the bottom of the pile. You should then be able to lightly using a spade or your hands to skim castings off the top of the pile and continue to work to the bottom of the pile until you find any worms cuddled together. Then just put them back in the bin.
An easier but more expensive option is to purchase a professional worm harvester maching. Many of these cost well over $1,000 so not usually a good option for the home composter.
Another method is to use a secondary container about half full with new bedding material. Then lay a plastic garbage bag over the top (draping excess bag over edges is fine and preferred). Poke several holes into the plastic about the size of a pencil or pen. Then pour your castings on top of the plastic bag. Use the same method of shining a light on the castings and you can work the castings around with a garden spade or fork. You are in essence chasing the worms out of the castings and they'll escape through the holes in the plastic bag and into the new fresh bedding.
Some people even make home-made screening trays with 1/4 inch mesh fencing attached to 1 inch by 4 inch boards forming a small box (screen on bottom). They you can pour your castings into the box and gently shake the castings through and catch them in another container. |
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