Worm Dirt Harvesting
Apr. 8th, 2026 08:01 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
rebeccmeister posting in ![[community profile]](https://www.dreamwidth.org/img/silk/identity/community.png){kind=small}
gardeningThis is largely cross-posted from my personal blog, since I figure a lot of us spend a lot of time thinking about soil quality and composting! I love worm bins because they can be made to work for all kinds of lifestyles, including people who live in apartments, since a well-managed bin does not smell and can be designed to fit in all kinds of spaces.
I think I'm reaching the stage where there's something of a steady-state for managing my new-ish worm bin bench. To begin with, by myself I generate around 1 batch of kitchen scraps a week that can go into the bin. My kitchen scraps mostly include spent coffee grounds, banana peels, apple cores, and vegetable trimmings from whatever I happen to be cooking that week. Eggshells now get handled separately, and citrus goes into the yard compost outside because citrus is toxic to worms.
Last week I buried the paper sandwich bag full of kitchen scraps in the lower right corner of the bin, which is the end of the sequence of places for burying the scraps. Here are the bin contents, before I got started:
You can kind of see that the material on the left side is much more broken down compared to the material on the right side, because that's where I first started adding scraps to the bin, then worked my way down a column before progressing from left to right.
For whatever reason, this bin has been FULL of isopods, and often when I open it up a house centipede or two panics and runs to hide somewhere. There was also a time when I opened up the bin and something larger flew out, but I don't know what it was, just that there were some substantial wing-flapping noises. Exciting.
This photo is intended to give you a sense of the depth of the worm dirt:
The worm dirt comes up to somewhere between 4-5 inches on the hand rake. Hand rakes are really great for moving worm dirt around in the bin because they are less likely than a trowel to hurt the worms. Note that the worms in this bin are Red Wrigglers, which are widely used for fishing and definitely not one of the species native to New York. But at this point most of the native worm species have been displaced because humans move dirt around way too much, myself included. Try as I might, I never get all the worms out of the worm dirt, so our garden is probably also full of Red Wrigglers by now.
You can also see that some materials don't break down as easily as others in the worm bin (corncobs, avocado pits). More on that soon.
To harvest the dirt, I scoop up trowel-fulls and put them in this heavy duty plant tray so I can go through the dirt by hand:
When I go through the dirt by hand, I'm looking for a couple different things. Anything that hasn't composted down to a small size grain yet, I'll remove and throw back into the bin. On that front I'm wondering whether peach pits will ever decompose, or whether I should do something else with them instead (chop them up somehow? Give them to the squirrels?). The avocado pits DO eventually break down, it just takes longer for that to happen. I'm also looking for worms; if the dirt is fairly full of worms, I'll use a modified "pile" technique to harvest just the dirt and concentrate the worms so I can put them all back in the bin.
Here's a look at the bin after I pulled out about 5 gallons worth of worm dirt, which only emptied the bin out by about 1/4:
There weren't very many worms in the soil I pulled out, which is unsurprising because most of the material on the left side of the bin was already broken down. If I had dug into the fresher material on the right side of the bin I would expect to find far more worms.
I also have to fish out the Wishful Composting items when I'm sorting. This is like Wishful Recycling, where people put things into their recycling bins that they wish were recyclable, but that instead contaminate the things that are actually recyclable and cause recycling companies to refuse to collect and recycle anything.
The bag in this picture is covered in writing declaring that it's home compostable. It is showing some signs of disintegrating, so I buried it again to see if the disintegration will continue. If not I'll put it in the outdoor compost, which generally functions as a hot compost. There are also several chunks of a torn-up milk carton in this photo. My understanding is that historically, milk cartons were coated with wax to waterproof them. However, these chunks of torn up milk carton appear to have been coated with plastic instead. I personally just put milk cartons into the trash these days because I just don't trust that they'll actually decompose. And I try to buy most of my milk in reusable glass bottles, but sometimes in a pinch we still get stuff in the cartons. Fishing out all these pieces was vexing.
It's a bit hard to see, but there's also a push pin sitting in the middle of the "plastic" bag. I have no idea how a push pin wound up in the worm bin, but it's out now. I re-buried all of the peach and avocado pits for another round.
Here I'm about to add the next batch of kitchen scraps in a spot below where I re-buried the peach and avocado pits. I've also added in some torn-up egg carton and brown paper for extra carbon sources for the worms:
And here we are after the addition of a week's worth of kitchen scraps. I covered this stuff with a layer of worm dirt after taking this photo, because the worms don't like to travel at the surface, and burying the compost also makes it harder for fly eggs to develop.
In the kitchen I generally put a scavenged paper bag into that cream-colored flowerpot as the place to accumulate the kitchen scraps. If the kitchen compost is taken out once a week we generally won't have too many issues in the kitchen with fruit flies. The paper bag helps to make flowerpot cleanup easier, and provides more carbon for the worms. This particular paper bag might wind up causing similar issues as the milk carton, however; it is lined with some unknown substance, most likely because it came from a bakery that sells deliciously fatty baked goods and the bakery doesn't want the fat seeping into the bags. Once again, historically the lining would have been wax, but it's hard to tell what's on this newer bag and whether or not it will compost.
And there you have it. I think from this point I'll keep adding bags across until I reach around the halfway point, and then there will probably be another round of worm dirt harvesting.
The 5 gallons of worm dirt all got applied to garden beds outside. Worm castings tend to contain a ton of beneficial microbes, in addition to providing lots of nutrients in plant-friendly forms. Soil can be top-dressed with the dirt, making the application very straightforward.
I think I'm reaching the stage where there's something of a steady-state for managing my new-ish worm bin bench. To begin with, by myself I generate around 1 batch of kitchen scraps a week that can go into the bin. My kitchen scraps mostly include spent coffee grounds, banana peels, apple cores, and vegetable trimmings from whatever I happen to be cooking that week. Eggshells now get handled separately, and citrus goes into the yard compost outside because citrus is toxic to worms.
Last week I buried the paper sandwich bag full of kitchen scraps in the lower right corner of the bin, which is the end of the sequence of places for burying the scraps. Here are the bin contents, before I got started:
You can kind of see that the material on the left side is much more broken down compared to the material on the right side, because that's where I first started adding scraps to the bin, then worked my way down a column before progressing from left to right.
For whatever reason, this bin has been FULL of isopods, and often when I open it up a house centipede or two panics and runs to hide somewhere. There was also a time when I opened up the bin and something larger flew out, but I don't know what it was, just that there were some substantial wing-flapping noises. Exciting.
This photo is intended to give you a sense of the depth of the worm dirt:
The worm dirt comes up to somewhere between 4-5 inches on the hand rake. Hand rakes are really great for moving worm dirt around in the bin because they are less likely than a trowel to hurt the worms. Note that the worms in this bin are Red Wrigglers, which are widely used for fishing and definitely not one of the species native to New York. But at this point most of the native worm species have been displaced because humans move dirt around way too much, myself included. Try as I might, I never get all the worms out of the worm dirt, so our garden is probably also full of Red Wrigglers by now.
You can also see that some materials don't break down as easily as others in the worm bin (corncobs, avocado pits). More on that soon.
To harvest the dirt, I scoop up trowel-fulls and put them in this heavy duty plant tray so I can go through the dirt by hand:
When I go through the dirt by hand, I'm looking for a couple different things. Anything that hasn't composted down to a small size grain yet, I'll remove and throw back into the bin. On that front I'm wondering whether peach pits will ever decompose, or whether I should do something else with them instead (chop them up somehow? Give them to the squirrels?). The avocado pits DO eventually break down, it just takes longer for that to happen. I'm also looking for worms; if the dirt is fairly full of worms, I'll use a modified "pile" technique to harvest just the dirt and concentrate the worms so I can put them all back in the bin.
Here's a look at the bin after I pulled out about 5 gallons worth of worm dirt, which only emptied the bin out by about 1/4:
There weren't very many worms in the soil I pulled out, which is unsurprising because most of the material on the left side of the bin was already broken down. If I had dug into the fresher material on the right side of the bin I would expect to find far more worms.
I also have to fish out the Wishful Composting items when I'm sorting. This is like Wishful Recycling, where people put things into their recycling bins that they wish were recyclable, but that instead contaminate the things that are actually recyclable and cause recycling companies to refuse to collect and recycle anything.
The bag in this picture is covered in writing declaring that it's home compostable. It is showing some signs of disintegrating, so I buried it again to see if the disintegration will continue. If not I'll put it in the outdoor compost, which generally functions as a hot compost. There are also several chunks of a torn-up milk carton in this photo. My understanding is that historically, milk cartons were coated with wax to waterproof them. However, these chunks of torn up milk carton appear to have been coated with plastic instead. I personally just put milk cartons into the trash these days because I just don't trust that they'll actually decompose. And I try to buy most of my milk in reusable glass bottles, but sometimes in a pinch we still get stuff in the cartons. Fishing out all these pieces was vexing.
It's a bit hard to see, but there's also a push pin sitting in the middle of the "plastic" bag. I have no idea how a push pin wound up in the worm bin, but it's out now. I re-buried all of the peach and avocado pits for another round.
Here I'm about to add the next batch of kitchen scraps in a spot below where I re-buried the peach and avocado pits. I've also added in some torn-up egg carton and brown paper for extra carbon sources for the worms:
And here we are after the addition of a week's worth of kitchen scraps. I covered this stuff with a layer of worm dirt after taking this photo, because the worms don't like to travel at the surface, and burying the compost also makes it harder for fly eggs to develop.
In the kitchen I generally put a scavenged paper bag into that cream-colored flowerpot as the place to accumulate the kitchen scraps. If the kitchen compost is taken out once a week we generally won't have too many issues in the kitchen with fruit flies. The paper bag helps to make flowerpot cleanup easier, and provides more carbon for the worms. This particular paper bag might wind up causing similar issues as the milk carton, however; it is lined with some unknown substance, most likely because it came from a bakery that sells deliciously fatty baked goods and the bakery doesn't want the fat seeping into the bags. Once again, historically the lining would have been wax, but it's hard to tell what's on this newer bag and whether or not it will compost.
And there you have it. I think from this point I'll keep adding bags across until I reach around the halfway point, and then there will probably be another round of worm dirt harvesting.
The 5 gallons of worm dirt all got applied to garden beds outside. Worm castings tend to contain a ton of beneficial microbes, in addition to providing lots of nutrients in plant-friendly forms. Soil can be top-dressed with the dirt, making the application very straightforward.