Harvesting Our Vermicompost (Worm Compost)

Toddlers enjoying composting!

By Julie Goldstein

In previous blogs we’ve talked about the benefits of composting and how it’s done (link here). Composting with worms is a fun way to compost with your kids. Worms + Kids = Win! Recently we had fun harvesting the finished product from all our composting efforts with our worms. It usually takes about 3 months or more before your worm bin will be ready to harvest. There are several ways to harvest vermicompost (also known as worm castings). Here is a great blog from a place I used to work about the many ways to do it. With kiddos, I prefer to use the volcano/cone method. In short, once you see that your worm bin looks like crumbly brown dirt, you can dump it out into a cone shape and allow the worms to migrate inward to avoid light. Here is an excerpt from the aforementioned blog that explains the process…

Toddler harvesting vermicompost

“The VOLCANO/CONE METHOD is practiced by emptying out the bin contents onto a stable surface (that you don’t mind getting dirty) and sorting the castings into loosely-packed, cone-shaped piles. The worms will continually burrow away from the edges to escape the light, allowing you to scrape the worm-free castings off of the tops and sides of the piles. Take a 15-minute break after each round of castings removal to allow worms time to move inward. Repeat this process several times until only small piles of worms and castings remain; these can be placed into a bin with fresh bedding and food scraps.” (Retrieved from

Volcano of compost

We didn’t exactly wait the 15 minutes since the kids were having too much fun finding the worms =). In conjunction with this, the kids helped create a new worm bin tray so the worms had a new home after we harvested the castings. The kids had so much fun helping our worms and finding and collecting them all from the volcano piles. As one child said, “This is the best day EVER!” =). Next, we’ll use our harvested worm castings to make an easy seed starting mix. Keep an eye out for that recipe in an upcoming blog. Happy composting!

Placing fresh compost soil on bedding

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