Do I need to change the soil inside a worm farm?

Question

I want to know if it is necessary to move a worm population to a second container with fresh soil after a period of time? If so, how often does this need to be done?

I followed a DIY video from a popular gardening program and they said to have three containers, one for collecting the runoff / castings, one for the current population to live in and then a third container which you would place on top after a period of time.

The video said once food runs out in the second container they would climb up into the new container and you could switch out the old container and place that mixture into your garden. Then repeat this process.

Answer 1

There is no need to add or change soil in a stackable worm farm. If a tray is full you just start placing food in an empty tray above. The material in the new tray will decompose and turn into soil eventually. After a while, when the top tray starts to fill, the worms will move there provided the conditions in the bin are right and the worms have good access to the top tray (obviously the lower tray should be completely filled for this). If you wait a bit longer all eggs in the lower tray will have hatched, so the baby worms can move to the top as well and you can start harvesting vermicompost from the bottom tray.

Note that tray systems work well with the most-used and popular Eisenia Fetida worms that like to live just below the surface so tend to crawl up, but less well with other species like Eisenia Hortensis that tend to crawl all over the place.

Answer 2

Sounds like the video was pretty good. This sounds like a stackable system. They seem to be the least labor intensive. Eventually you would want the worms to move from the lowest level because you should harvest the worm castings.

You may still have some stragglers in the lower level of castings so if you're making tea or anything other than top dressing plants with the castings you might want to spread the castings out on a tarp under a bright light or the sun. The worms will work their way to the bottom to avoid the light and you can collect them and add them back to the working bin.