Your worm bin is ready for harvesting when:

  • The bottom layers are vermicompost, with a deep, rich color and uniform texture.
  • Worm production is slow, and you see fewer cocoons being produced.
  • The worms are smaller, indicating that they need fresh bedding and food.
  • The bin is full, and will not accommodate additional bedding and food.

What you’ll find in your bin, in addition to worms:

Vermicompost is a mixture of uneaten food (organic matter) and worm castings (worm poop). It is beneficial for worms – as it contains available food – and for the soil. Over time, the worms will eat the organic matter in the soil, and convert it into castings. Vermicompost can be added directly to your garden or plants, but you will likely relocate some worms in the process. To avoid this, you can sift the vermicompost to separate the castings and retain the worms for your bin.

Worm Castings are the most beneficial fertilizer and soil conditioner known to humans. They are deep brown in color, and have a consistency similar to coffee grounds.

Cocoons. Red wigglers reproduce via cocoons, which can contain between 1-20 baby worms (the average is 4-6). A healthy worm bin will be full of cocoons – make sure to add them to your new bin to increase your worm population. For more information, see the life cycle of a worm.

When you’re ready to harvest:

If you have a plastic bin, add food to only one corner, to attract worms to one location. Or, put food scraps in a mesh produce bag (like an onion or citrus bag) or a burlap bag, and seal the bag. Bury it in your bin to attract the worms. After a few weeks, pull out your bag of worms! 

If you have a stackable system, stop feeding the current tray, and add food and bedding to the next level. Your worms will migrate up when they have eaten all available organic matter in the current tray.  

If you have a divided bin system, stop feeding the current side, and add bedding and food to the next section. 

Alternatively, gently scoop your bin’s contents onto a tarp, and carefully remove the worms and cocoons by hand. If desired, you can then sift the resulting vermicompost to separate the castings.