Worm composting bin overfloweth!
May 4, 2011 6:37 PM Subscribe
Two months into my vermicomposting and my worms are still alive, which means something must be going right. The bad news is I'm crushing them with vegetable matter. How can I keep my compost from overflowing?
When I was doing my research, most sites suggested a bin not much larger than a shoebox for 1-2 people. Since I almost always cook with fresh ingredients, I bought a 17 gallon container...now that is packed to brim.
Since I'm unable to fit any more cardboard inside, the aromas are getting stronger...but more than anything, I'm just out of space.
Because I've been turning it, it's pretty a pretty heteregeneous mix of worm poop, eggshells, apple cores and the like. It doesn't seem like I would be able to piece apart the decomposed matter.
Is there something I'm not thinking of here? I'm about to go upgrade to an even larger bin, but since I live in an apartment, I do have space constraints.
Thanks!
When I was doing my research, most sites suggested a bin not much larger than a shoebox for 1-2 people. Since I almost always cook with fresh ingredients, I bought a 17 gallon container...now that is packed to brim.
Since I'm unable to fit any more cardboard inside, the aromas are getting stronger...but more than anything, I'm just out of space.
Because I've been turning it, it's pretty a pretty heteregeneous mix of worm poop, eggshells, apple cores and the like. It doesn't seem like I would be able to piece apart the decomposed matter.
Is there something I'm not thinking of here? I'm about to go upgrade to an even larger bin, but since I live in an apartment, I do have space constraints.
Thanks!
A shoebox? Jeez. I have one big container, probably going to get another. There is a max to what they can process a week, and also the bigger it is, the worse it is. If you take some time and cut stuff up smaller it'll decompose faster. Probably you'll need to do traditional composting with your extra ingredients, or expand to another container.
posted by RustyBrooks at 6:55 PM on May 4, 2011
posted by RustyBrooks at 6:55 PM on May 4, 2011
Don't add more scraps. Let the worms process what's there, feed it slower until you get a good solid layer of vermicompost that you can remove to make more room again . In the meantime, just put a big tub in the freezer and throw your scraps in there - they'll freeze solid and won't smell a bit while they wait for space in the worm box.
posted by jardinier at 7:10 PM on May 4, 2011
posted by jardinier at 7:10 PM on May 4, 2011
If it stinks, that means not enough air is getting in. 17 gallons is too big a container to aerate itself only through the top, even if you are turning it regularly (and the whole point of vermicomposting is that the worms are supposed to be doing that work for you). How do your aeration and drainage arrangements work?
In any case, if your bin is now full but you can still see whole apple cores in it, you're overfeeding it. Back off for a while, and when you resume it might help to smash the food up a bit more before adding it to the bin. I'm sure you'll find some electrical appliance or other that you could abuse for this purpose.
A good arrangement for an apartment vermicomposter is four stacking storage containers. Two of them get 1/4" holes bored all around the top half of the walls; they will be base boxes. The other two get lots of 1/4" holes bored all over the walls and through the bottom; they will be housing boxes.
To start with, fill one of the base boxes 3/4 full of dry sawdust, shredded newspaper, recycled-newspaper kitty litter or similar, to soak up the liquid worm manure that will drip down from the housing box. Now stack a housing box on top. If you've already got an active worm colony on the go in some inferior container, just dump the whole lot into the housing box; if starting afresh, put about two inches of spent mushroom compost or supermarket potting mix into the box, add 500 worms, and another inch of compost or mix to cover. Throw in your first day's worth of smashed scraps, then stack on the second housing box, and top with the spare base box.
Every day, lift off the top base box, transfer the top housing box onto that, and add more smashed scraps to the active housing box. Keep an eye on the level of scraps in that box, and back off the feeding rate as needed so you're never actually squashing scraps when you put the top housing box back on.
You should find that as your worms breed up, the pre-feeding scraps level gets a little lower every day. Worms working well can typically turn one gallon of raw scraps into a tenth of a gallon of crumbly worm castings.
However, at some point this trend will reverse. That's your cue that the colony is slowing down and wants moving to a new home. So instead of lifting both top boxes, just start putting your scraps into the top housing box at about the same rate you were already feeding the bottom one.
After a month or so you should find that most of the worms have migrated into the top housing box where the food is now coming from. At this point you can take off the top base box, fill it 3/4 full of dry sawdust, and stack the top housing box directly onto that.
Your old housing box will now be full of crumbly worm castings, and the absorbent from your old base box will be well soaked with liquid worm manure. Dig the castings into the soil of whichever garden bed is crying out for them, then dump the absorbent on top of that as mulch; then put the old housing box on top of the new one, and the old base box on top of the whole stack, and you're back into the feeding cycle.
I like this arrangement much, much better than the commercial worm farms I've seen, all of which seem far too crowded, flimsy, messy to operate, and end up with a liquid manure tray full of stinking drowned worms. You can't really keep the stack in a cupboard, though; it relies on worms' distaste for light to stop them wandering out of the box and surprising your guests.
posted by flabdablet at 10:02 PM on May 4, 2011 [11 favorites]
In any case, if your bin is now full but you can still see whole apple cores in it, you're overfeeding it. Back off for a while, and when you resume it might help to smash the food up a bit more before adding it to the bin. I'm sure you'll find some electrical appliance or other that you could abuse for this purpose.
A good arrangement for an apartment vermicomposter is four stacking storage containers. Two of them get 1/4" holes bored all around the top half of the walls; they will be base boxes. The other two get lots of 1/4" holes bored all over the walls and through the bottom; they will be housing boxes.
To start with, fill one of the base boxes 3/4 full of dry sawdust, shredded newspaper, recycled-newspaper kitty litter or similar, to soak up the liquid worm manure that will drip down from the housing box. Now stack a housing box on top. If you've already got an active worm colony on the go in some inferior container, just dump the whole lot into the housing box; if starting afresh, put about two inches of spent mushroom compost or supermarket potting mix into the box, add 500 worms, and another inch of compost or mix to cover. Throw in your first day's worth of smashed scraps, then stack on the second housing box, and top with the spare base box.
Every day, lift off the top base box, transfer the top housing box onto that, and add more smashed scraps to the active housing box. Keep an eye on the level of scraps in that box, and back off the feeding rate as needed so you're never actually squashing scraps when you put the top housing box back on.
You should find that as your worms breed up, the pre-feeding scraps level gets a little lower every day. Worms working well can typically turn one gallon of raw scraps into a tenth of a gallon of crumbly worm castings.
However, at some point this trend will reverse. That's your cue that the colony is slowing down and wants moving to a new home. So instead of lifting both top boxes, just start putting your scraps into the top housing box at about the same rate you were already feeding the bottom one.
After a month or so you should find that most of the worms have migrated into the top housing box where the food is now coming from. At this point you can take off the top base box, fill it 3/4 full of dry sawdust, and stack the top housing box directly onto that.
Your old housing box will now be full of crumbly worm castings, and the absorbent from your old base box will be well soaked with liquid worm manure. Dig the castings into the soil of whichever garden bed is crying out for them, then dump the absorbent on top of that as mulch; then put the old housing box on top of the new one, and the old base box on top of the whole stack, and you're back into the feeding cycle.
I like this arrangement much, much better than the commercial worm farms I've seen, all of which seem far too crowded, flimsy, messy to operate, and end up with a liquid manure tray full of stinking drowned worms. You can't really keep the stack in a cupboard, though; it relies on worms' distaste for light to stop them wandering out of the box and surprising your guests.
posted by flabdablet at 10:02 PM on May 4, 2011 [11 favorites]
I think the trick is to keep the veg matter and them kind of separated with cardboard.
posted by watercarrier at 4:40 AM on May 5, 2011
posted by watercarrier at 4:40 AM on May 5, 2011
Re: shoebox - sites I've seen recommend about 1 square foot surface area per person, and a depth of around 8-10 inches. A shoebox is about 0.5 sqft. That'll never do.
The depth is important only because something too deep loses air circulation, so worms don't hang out deeper than 10 inches or so. Right now my bin (also a 17-gallon one) is about 5" of castings on bottom, 5" of food in the middle, and 5" of paper on top, so the castings layer is deeping than they want to live.
Short-term advice: Your bin is full, it's time to harvest. See below.
In the longer term, you've got a fine bin. Though a single-bin setup is more challenging than the swank worm tower that flabdablet recommends, it's also cheaper, and you've already got it going on, so I'd try to just go with it.
Food-adding advice:
-- Eggshells take forever to go away. Worms don't really find them delicious; I don't know if they eat them at all or if they just kind of break down as compost over time. In future, add those only occasionally, and try to break them up pretty well first. (If you grow tomatoes, you can wash the eggshells, set aside till planting time, crush them up in a mortar/pestle and add the crush under the seedlings as you plant them - extra calcium helps with blossom end rot.) For now, just assume there will be pieces of eggshell in the stuff you add to the garden. The plants will honestly not mind one bit.
-- Since you cook so much from scratch, you're probably overfeeding for the size of your box. technically it's 1 sqft per pound of scraps per week. Your bin is probably about 2x1.5 feet, or 3 square feet, i.e. under ideal conditions, your worms can handle about half a pound of scraps per day. Consider actually weighing a few batches before you add it to help calibrate your mental estimates of how much volume a half-pound is.
-- If you are giving them a lot of wet/watery food (lettuce/leaves, melon, tomato, etc) as opposed to dry food (broccoli stems, bread crusts, cabbage cores) then the poop part will get wet/soggy, and that's when it will start to stink. Too much liquid means not enough oxygen and anaerobic decompositiion is the noxious kind. That's when you need to add extra paper to keep it dry. And I had to stop putting lettuce in mine, it was just out of control wet.
Don't turn the compost, as such. Try to keep the layers as layers. You start out with a bin full of paper shred, and add worms. Bury a pile of scraps in the corner, and work your way methodically around the bin over the next weeks, such that if there were no worms, you'd have a dozen little piles of scrap on the bottom of the box, and a layer of paper shred over the top. The magic is that 2 weeks later when you cycle back to the corner you started in, you find only the woodiest part of the scraps, surrounded by writhing worms and some worm poop. Tuck more garbage in and continue the cycle, but try to always keep your scrap low in the bin, and not exactly mixed with the paper.
Ending the cycle is a major challenge. I have 2 17-gal bins, and when one was full, I filled the other with 10" of paper shred, added some scraps to the bottom of it, and set it on top of the worms in the full bin. Then I actually stopped feeding them at all for over a week. There was plenty of food in the bottom bin that they needed to finish up before they'd be at all hungry, the bottom bin wasn't too soggy so I didn't have to add extra paper, and I was going out of town for a few days. I did end up throwing out some scrap, just to give the little guys a break. Then I started adding scrap to the top bin. Just pretended the bottom bin wasn't there for another week or so. Went back and checked that worms were starting to turn up in the first place I'd buried scrap, and that was reassuring. (note, worms don't actually like fresh food, it's not interesting to them until it's almost a week old.) I did go into the bottom bin and pull out the major chunks of things they weren't eating. Threw out some woody brussels sprout stalks they weren't that interested in, transferred a rotting potato that I hadn't cut up into the top bin (note, cut up food into chunks or they'll take forever), transferred any big clumps of worms I encountered. But by the end of a couple of weeks, the colony was pretty established in the top bin.
Then I moved the bottom bin out and went through it. There were still worms, pieces of eggshell, pieces of dry unappetizing food (they ate the insides of pumpkin seeds and left the shells), pieces of paper, etc. The challenge was the mental shift - it's okay if the stuff I dig into my garden bed doesn't look like store-bought compost. It's okay if my back yard garden bed has little bits of newspaper and pumpkin hulls in it, they will eventually decompose and it's nothing compared to the number of twigs and maple leaves that drift in there. It's okay if 20% of my worm colony ends up outside and only 80% makes the transfer to the new bin - they're in there having babies at an alarming rate, they'll catch up in a few weeks. So don't sweat it, just dump the compost into the garden. If you do see something you don't want there, pull it out. Deciding when it harvest the worm castings is like deciding when to stop scooping cat litter and dump the whole thing out for a cleaning - it will never be completely ready, you will always be (dumping clean litter) putting undigested bits into your garden, but that's okay. They will decompose outside at their own rate.
Advice for specifically your overfull bin in the short term:
Stop feeding for at least a week, which will mean throwing out your scraps for a little while. After a week, check on the bin and don't let it get too wet (I've never had a problem with it getting too dry). If they're doing truly fine, let it go another week. If you can buy a second bin to work with, now would be the time to add it. If you can't buy a second bin, make a hollow in one corner (the corner closest to the most recent scrap additions), and put in a bit of fresh scrap and cover with fresh dry paper shred. Don't stir, that corner is your "new bin". If you have one handy, cut a piece of hardware cloth (1/2" metal mesh) and stick it across the center line of your bin as a divider. Add only a little bit of scrap to only that corner, and make sure that corner is as welcoming humidity as possible. As they're getting done with the rest of the bin, they'll gravitate toward your new corner. Start removing trowelsful of compost from the opposite corner into a bucket; collect to transfer out to the garden. Go slow. It'll probably be at least another week or two before you've emptied out half the bin; don't stir it, don't smooth it out, just let that open space accumulate next to the pile that is the other half. If you used hardware cloth, that's helping keep the occupied half from falling into the empty half. Now you've got half a bin empty, and that becomes your "new bin". Fill with paper shred and start adding scraps. Eventually the colony will migrate over (through the hardware mesh) and you can scoop the other half out into your garden. Whether you keep the hardware cloth in and keep thinking of your bin in two halves is up to you, it may make the next harvest easier but it's kind of annoying in the meantime.
Sorry to ramble. I'm not an expert, I killed my first worm colony (its name was Harvey) but the second worm colony seems to be doing okay.
posted by aimedwander at 7:30 AM on May 5, 2011 [5 favorites]
The depth is important only because something too deep loses air circulation, so worms don't hang out deeper than 10 inches or so. Right now my bin (also a 17-gallon one) is about 5" of castings on bottom, 5" of food in the middle, and 5" of paper on top, so the castings layer is deeping than they want to live.
Short-term advice: Your bin is full, it's time to harvest. See below.
In the longer term, you've got a fine bin. Though a single-bin setup is more challenging than the swank worm tower that flabdablet recommends, it's also cheaper, and you've already got it going on, so I'd try to just go with it.
Food-adding advice:
-- Eggshells take forever to go away. Worms don't really find them delicious; I don't know if they eat them at all or if they just kind of break down as compost over time. In future, add those only occasionally, and try to break them up pretty well first. (If you grow tomatoes, you can wash the eggshells, set aside till planting time, crush them up in a mortar/pestle and add the crush under the seedlings as you plant them - extra calcium helps with blossom end rot.) For now, just assume there will be pieces of eggshell in the stuff you add to the garden. The plants will honestly not mind one bit.
-- Since you cook so much from scratch, you're probably overfeeding for the size of your box. technically it's 1 sqft per pound of scraps per week. Your bin is probably about 2x1.5 feet, or 3 square feet, i.e. under ideal conditions, your worms can handle about half a pound of scraps per day. Consider actually weighing a few batches before you add it to help calibrate your mental estimates of how much volume a half-pound is.
-- If you are giving them a lot of wet/watery food (lettuce/leaves, melon, tomato, etc) as opposed to dry food (broccoli stems, bread crusts, cabbage cores) then the poop part will get wet/soggy, and that's when it will start to stink. Too much liquid means not enough oxygen and anaerobic decompositiion is the noxious kind. That's when you need to add extra paper to keep it dry. And I had to stop putting lettuce in mine, it was just out of control wet.
Don't turn the compost, as such. Try to keep the layers as layers. You start out with a bin full of paper shred, and add worms. Bury a pile of scraps in the corner, and work your way methodically around the bin over the next weeks, such that if there were no worms, you'd have a dozen little piles of scrap on the bottom of the box, and a layer of paper shred over the top. The magic is that 2 weeks later when you cycle back to the corner you started in, you find only the woodiest part of the scraps, surrounded by writhing worms and some worm poop. Tuck more garbage in and continue the cycle, but try to always keep your scrap low in the bin, and not exactly mixed with the paper.
Ending the cycle is a major challenge. I have 2 17-gal bins, and when one was full, I filled the other with 10" of paper shred, added some scraps to the bottom of it, and set it on top of the worms in the full bin. Then I actually stopped feeding them at all for over a week. There was plenty of food in the bottom bin that they needed to finish up before they'd be at all hungry, the bottom bin wasn't too soggy so I didn't have to add extra paper, and I was going out of town for a few days. I did end up throwing out some scrap, just to give the little guys a break. Then I started adding scrap to the top bin. Just pretended the bottom bin wasn't there for another week or so. Went back and checked that worms were starting to turn up in the first place I'd buried scrap, and that was reassuring. (note, worms don't actually like fresh food, it's not interesting to them until it's almost a week old.) I did go into the bottom bin and pull out the major chunks of things they weren't eating. Threw out some woody brussels sprout stalks they weren't that interested in, transferred a rotting potato that I hadn't cut up into the top bin (note, cut up food into chunks or they'll take forever), transferred any big clumps of worms I encountered. But by the end of a couple of weeks, the colony was pretty established in the top bin.
Then I moved the bottom bin out and went through it. There were still worms, pieces of eggshell, pieces of dry unappetizing food (they ate the insides of pumpkin seeds and left the shells), pieces of paper, etc. The challenge was the mental shift - it's okay if the stuff I dig into my garden bed doesn't look like store-bought compost. It's okay if my back yard garden bed has little bits of newspaper and pumpkin hulls in it, they will eventually decompose and it's nothing compared to the number of twigs and maple leaves that drift in there. It's okay if 20% of my worm colony ends up outside and only 80% makes the transfer to the new bin - they're in there having babies at an alarming rate, they'll catch up in a few weeks. So don't sweat it, just dump the compost into the garden. If you do see something you don't want there, pull it out. Deciding when it harvest the worm castings is like deciding when to stop scooping cat litter and dump the whole thing out for a cleaning - it will never be completely ready, you will always be (dumping clean litter) putting undigested bits into your garden, but that's okay. They will decompose outside at their own rate.
Advice for specifically your overfull bin in the short term:
Stop feeding for at least a week, which will mean throwing out your scraps for a little while. After a week, check on the bin and don't let it get too wet (I've never had a problem with it getting too dry). If they're doing truly fine, let it go another week. If you can buy a second bin to work with, now would be the time to add it. If you can't buy a second bin, make a hollow in one corner (the corner closest to the most recent scrap additions), and put in a bit of fresh scrap and cover with fresh dry paper shred. Don't stir, that corner is your "new bin". If you have one handy, cut a piece of hardware cloth (1/2" metal mesh) and stick it across the center line of your bin as a divider. Add only a little bit of scrap to only that corner, and make sure that corner is as welcoming humidity as possible. As they're getting done with the rest of the bin, they'll gravitate toward your new corner. Start removing trowelsful of compost from the opposite corner into a bucket; collect to transfer out to the garden. Go slow. It'll probably be at least another week or two before you've emptied out half the bin; don't stir it, don't smooth it out, just let that open space accumulate next to the pile that is the other half. If you used hardware cloth, that's helping keep the occupied half from falling into the empty half. Now you've got half a bin empty, and that becomes your "new bin". Fill with paper shred and start adding scraps. Eventually the colony will migrate over (through the hardware mesh) and you can scoop the other half out into your garden. Whether you keep the hardware cloth in and keep thinking of your bin in two halves is up to you, it may make the next harvest easier but it's kind of annoying in the meantime.
Sorry to ramble. I'm not an expert, I killed my first worm colony (its name was Harvey) but the second worm colony seems to be doing okay.
posted by aimedwander at 7:30 AM on May 5, 2011 [5 favorites]
A few years ago I set up a series of three 3' tall 4'x4' pens in which I put all the sawdust and shavings from my shop and my wife throws kitchen scraps, dead leaves, lawn clippings and other garden type waste. We can fill a 4x4 pen two or three times a year, so figure we turn things over every three or four months with a total cycle time of six months at the very least. (It's faster in the summer.)
I'd suggest you take what you have out to your garden, dump out, and put what was the top third or so of your pile back into your container and proceede from there. I wouldn't go to great lengths to concentrate the worms in that third, but with 48 cubic foot bins, I'm not trying to establish a high speed earthworm archology or anything.
Sow bugs, aka wood lice, aka rolly pollys etc. do a number on some of the chunkier things in a compost pile. I have, for example, seen them make small tree limbs go away! Adding a few of those to the mix might act as a two prong attack and accelerate the breakdown, but I'm not sure what you do to convince them not to depart the buffet you're offering and go for a walk about with an in the house bin.
posted by Kid Charlemagne at 12:50 PM on May 5, 2011
I'd suggest you take what you have out to your garden, dump out, and put what was the top third or so of your pile back into your container and proceede from there. I wouldn't go to great lengths to concentrate the worms in that third, but with 48 cubic foot bins, I'm not trying to establish a high speed earthworm archology or anything.
Sow bugs, aka wood lice, aka rolly pollys etc. do a number on some of the chunkier things in a compost pile. I have, for example, seen them make small tree limbs go away! Adding a few of those to the mix might act as a two prong attack and accelerate the breakdown, but I'm not sure what you do to convince them not to depart the buffet you're offering and go for a walk about with an in the house bin.
posted by Kid Charlemagne at 12:50 PM on May 5, 2011
Something else that can help keep a colony smelling sweet is dolomite. If you can find it crushed to the texture of fine sand, use that; if all you can get is powder, that's an OK second best. As well as regulating the acidity of what's in your bin, sprinkling in a teaspoon of dolomite each week will help the worms grind up what they eat. It will eventually make useful amounts of magnesium and calcium available to your garden too.
posted by flabdablet at 8:55 PM on May 5, 2011
posted by flabdablet at 8:55 PM on May 5, 2011
This thread is closed to new comments.
posted by katinka-katinka at 6:48 PM on May 4, 2011