How to harvest compost from a worm bin

I’ve been vermicomposting for almost nine years so I’ve had plenty of experience harvesting compost from my worm bins. Several people have asked how I harvest compost from our vermicomposting bins so I thought I’d share how we harvest worm compost on our homestead.

Benefits of Worm Castings Compost

Worms are amazing little recyclers, processing organic matter into high quality compost. I’ve used a variety of composts in my gardens over the years, but hands down my favorite is the worm casting compost I harvest from our Red Wiggler vermicomposting bins.

You can take my word for it or if you’re curious to learn more, read the 101 worm compost benefits to plants and soil. Worm castings compost is amazing stuff!

Styles of Worm Compost Bins to Harvest

If you have a worm bin like this one I wrote about, you can just pull the tray the worms are not in to harvest the compost. This is the easiest worm bin to harvest compost from!

After using that style of worm bin for a year, I decided it is my least favorite worm bin of all the ones I’ve tried. In our dry climate I just couldn’t keep the worm bin wet enough so I switched to big bin style worm bins over five years ago and I love them!

We currently have two large vermicomposting bins that are very simple bins made out of a big plastic tub like this. There are no fancy layer systems and all the worms are in one big bin together.

While I love everything about these simple worm bins, they are a little more involved to harvest worm compost from.

My Method for Harvesting Worm Compost from a Vermicomposting Bin

I feed our vermicomposting worms once per week and always rotate where I feed them  EXCEPT when I know I’m going to harvest a bunch of compost. In that case, I feed the worms in the same corner of the bin at least two weeks in a row.

Why? This causes the majority of the worms to flock to the biggest food source so most of them are congregated together. Then when I go in to harvest compost, the rest of the bin is more sparsely populated with worms.

When I first started harvesting compost from my worm bins, I would try to not get a single worm in the compost. This was so time consuming!

I eventually got over that, and it helps that our worm bins are now much bigger with thriving populations of worms that can actually use a little downsizing a couple times a year.

Now I strive for getting as few worms as possible in the compost but don’t stress about it anymore since I know there are still thousands congregated together in the bin at the main food source.

Plus, the worms that are still in the compost will end up in my raised garden beds and they do wonders for aerating the soil.

I always keep a layer of shredded newspaper as the top layer in my worm bins. This helps to soak up some of the moisture in the bins and also provides another food source for the worms.

To harvest compost, I carefully rake back the shredded newspaper and pile it over the area where I fed the worms the last two weeks. Then I use a hand trowel and start scooping out compost into a bucket. It’s as simple as that!

I only harvest compost two to three times per year so when I do it, I take as much as possible. I try not to disturb the area where the worms are congregating until I’m done.

Then I carefully spread the leftover material and worms evenly over the inside of the worm bin to create an even level. I add a fresh layer of shredded newspaper.

Then I say thanks for the poop (what their compost really is!) and adios until their next feeding. Then I go spread the compost on our gardens.

Happy vermicomposting and gardening!

Do you have any tips to share on how to harvest compost from a Red Wiggler worm composting bin?