Harvesting Vermicompost

When Should I Harvest Vermicompost From My Worm Bin?

Now that your setup has been ongoing for a while, you are probably wondering when your worm bin is ready for harvest. The short answer: harvest when almost all of the bedding and food is turned into vermicast. If there’s too much bedding left, harvesting will be a waste of time. Wait a while until most of the contents of the bin have turned into vermicast. You can identify the vermicast by its small, pellet-like texture, and earthy smell. Any foul odors may indicate that something has gone wrong, or your bin is not ready for harvest.

Preparing A Bin For Harvest

It is recommended, though not required, for you to prepare a bin for harvesting. In order to do this, you have to basically do nothing. For a few days before harvest, do not feed, water, or add bedding to your worm bin. This makes the vermicompost drier, and easier to harvest. Also, you won’t have to separate as much bedding and food, and less foreign objects would end up in your final product.

Harvesting The Vermicompost

There are numerous methods of harvesting vermicompost from worm bins. However, we tend to prefer one particular method that is less labor-intensive, and relatively easy on the worms. This method is referred to as the pyramid harvesting method. This is much simpler than it sounds. It involves dumping the contents of a bin on a large tarpaulin in a bright environment, such as under a light, or preferably, in indirect sunlight. With the contents of the bin on the tarp, or any other flat surface, form a pyramid/cone-shaped pile. Because worms are light-sensitive, the worms will burrow towards the center of the pile. The outer surface of the pile can then be scraped off, and you will get vermicompost, without the worms. Remove the outer layers of the pile slowly, stopping when worms are visible. Keep repeating the process, until you end up with a pile of just worms. The worms can then be placed in fresh bedding, and the bin can be reused to start the vermicomposting process all over again.

Processing The Vermicompost

Vermicompost is a mixture of vermicast/worm castings and organic matter. This vermicompost can be further sifted in order to obtain pure vermicast. However, it is unnecessary and labor-intensive. In addition, the organic matter found in vermicompost is actually beneficial, and helps good bacteria thrive. However, vermicast might be preferred when creating your own vermi tea. To learn more about what vermi tea is and how to make it, check out our post about vermi tea.

Wet vermicompost does not sift well. Before any sifting is done, slowly dry out your vermicompost, out of direct sunlight, until it has a crumbly texture. In order to sift out foreign objects from your vermicompost, use a increasingly small screens. Start with a larger size, such as a 1/4″ mesh, down to an 1/8″ screen. This should give you pure vermicast, ready for use in brewing vermi tea, or as a fertilizer and soil conditioner.