How I Turned a Laundry Bag Into a Flow Through Worm Bag




Introduction: How I Turned a Laundry Bag Into a Flow Through Worm Bag

I was inspired by Amy Youngs instructable about making a felt version of a flow through worm inn. But I don't have all the tools to do the wood work that the frame requires, and I'm cheap. So while out shopping and looking for a cheaper alternative than buying a cord stop from Joannes, I figured I'd take the cord stop off of a cheap dollar store laundry bag. Then I noticed that the bag was non woven and probably not organic and wondered if I could just alter the bag itself to make the worm bag. This I made my own Flow Thru worm bag out of a dollar store laundry bag!

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Step 1: Materials List

I don't have exact measurements, as a lot of this is found material, but you get the idea. If you find a laundry bag in your store the dimensions might differ, but the concept would be the same.

-A non organic fiber laundry bag. Not cotton or linen, but polyester or something else synthetic. Honestly I don't know what this laundry bag is made of but it melts when it's near heat so it's probably plastic, not plant based.
-Polyester sewing thread
-Seam ripper or fingernail clippers work well, too
-Sewing machine with a zipper foot attachment
-a Long Zipper, long enough to go around 3 sides. I bought a spool of zipper with12  pre-threaded pulls. You just slide a pull to the middle and cut it to the size you need.
-Marking Chalk
-Tape measure
-3/4" PVC Pipe
-3/4" PVC 90 degree corner connectors x 8
-a fine saw or pipe cutter
-small plastic wash tub

Step 2: Reshaping the Bag

Open your laundry bag package and find the bottom. Using a seam ripper take off the square that is the bottom, trying not to damage the fabric itself, just cut through the connecting threads.

Also, remove the pocket that is attached to the side. This material will become the hanging straps, later.

Turn the bag inside out and fold down the raw edge about 2 inches, bad side together and sew it down to make a new finished edge.

Lay the bag flat and decide how small you want your bottom opening to be. I made it small enough to put my hand through. To figure this out, I laid the bag flat with the main vertical seam on the right and, in the center, marked two marks on either side of my hand at the bottom were the cord seam is.  I then laid the bag flat again so that main vertical seam was in the center, and measured my hand again. This created four marks that will be where I start sewing the new seams
Note: make sure the hole where the cord pull come out is within the hand marks.

From each mark, draw a straight line to the top corner of the bag right up to the new 2 inch seam you just sewed  and you will have a V shape. Start sewing from the top of the cord pull seam, do not sew through it, and sew a straight line all the way up to the corner.

When you finish, you will have a square "cone" with 4 "wings" sticking out. You should be able to pull the drawstring and close up the bottom tight. 

Cut the drawstring  and retie it shorter or you will have a long string flopping about soaking up leachate and wicking icky juicy all over the place.  I just opened the bottom hole fully to make sure I didn't cut it too short and not be able to open it fully ,  undid the cord knot, Pull one side down to the length I wanted. pulled the other side up through the cord stop till the excess ran through all of the gathers , cut off the excess  to match the new shorter length and retied it  (sorry no picture, I did this just a few minutes ago, after everything else was done and the cord was whipping coffee juice everywhere and I realized I needed to shorten the cord.)

Step 3: Add the Zipper

I spent two days trying to thread a zipper pull on to a "cut your own length" piece of zipper.  I went and bought Drisk Cut to size Upholstery Zipper with 12 pulls already attached. That way all I had to do is to pull one zipper pull to the center and measure what I needed and cut it off. the zipper pull keeps the zipper closed until you pull it all the way to one side.

So, turn the bag right side out and  measure from one corner, around 3 inner sides to the the other corner. the last side will be attached directly to the "lid" fabric without any zipper.

If you don't know how to install zippers, now is a good time to look up some you tube videos. I simply wanted the zipper to be "on the top" with zipped, so I pinned it with the zipper facing the 2 inch seam. I lined up the zipper along the thread line to make sure it was level. Do this around the 3 sides of the bag, making sure to overlap about half an inch at both ends.

I cheated at this point. You are supposed the fold the fabric back and butt it against the zipper and sew it on the good side, but I just put the zipper foot on and sewed it with the zipper upside down. I sewed it as close to the zipper as possible.  When you get to the slide pull, stop the machine with the needle down, lift the pressure foot, and slide the pull under to the finished side. Then replace the pressure foot and continue. the curves will need a bit of slow and steady.

Now you will need to pin the lid fabric to the zipper. I turned the bag inside out and pinned the lid fabric so that the very raw edge was matched up with the edge of the zipper. I did not pin the non zippered size. I then turned it right side out and that caused the fabric to fold  on the zipper fabric and I pinned the folded edge right next to the zipper. ( The first pins are inside I just removed them and repositioned them on top where I was holding the fold)

With the zipper foot on the other side, I sewed on the right side, with the zipper facing up the right way. Sew as closely to the zipper as possible going carefully around the corners. ( I did not snip the corners, but you can if you must.)

Lastly, I turned the bag inside out again and sewed down the last edge of the lid, then turned it right side out and reinforced that edge by sewing over it on the right side.   When you finish, you should have a zipper that is down inside the seam wall by about an inch, and opens three sides and folds open like a hinge on the sewn side.

Step 4: Holding Sleeves

Since I planned to make a PVC frame to hold this , I needed to make straps that would loop around the pipe. But this material is pretty thin, and I worried that a strap in a corner might pull out under the weight, so I opted to make sleeves that hold the weight over a space instead of one spot.

I took the pocket material and cut it into 4 equal squares. I had to Iron them a bit as they were terribly wrinkled.  Don't use high heat and don't put the iron directly on the material. Use a cotton or linen fabric between and the lowest setting for polyester. My iron fell over onto one piece briefly and instantly melted it, so I know for certain it's not a linen.

Anyway, using the PVC as a guide. I pinned off the part that would slide on. I folded the two flaps so they were double thick. I then lined it up with the center of each side and sewed along the edge all the way around in a square.

Step 5: Build the Frame

Hold your finished bag up to the PVC and figure out how many inches it goes across. Cut the PVC to that width, and measure and cut 3 more to the same width.  Slide the PVC into the holding straps and put the connectors on. You now have the square top. Cut 4 more lengths to be the bottom of the frame.  Hold up your bag to determine how high the frame needs to be to not touch the floor and how high above your drip pan it will be.

Cut the legs to how high you want it to be and cut 3 more the same length. Attach them to the connectors, and you have your finished frame. 

Step 6: Fill Your Worm Bag With Bedding , Food and Worms

This part is not detailed. Please visit websites for vermicomposting to get detailed instructions for how to care for your composting worms.

Here I've just added some bedding; egg crate, newspaper and coffee filter; Some Kitchen scraps and coffee grounds and my worms, who had previously been living in a bucket.

With the drip pan below to catch the leaking coffee grounds and any other liquid that seeps through, the worm bag is now occupied and ready to recycle some food into castings.

I'm hoping this bag will hold up as well as my shopping bags which seem to be made of the same material. Here is a photos of it filled at the bottom.

If it doesn't last forever that's okay. This mostly was an experiment to help me practice the concept,and I could make another with sturdier material later if need be.  the zipper would be easy to pull out and reuse  since it's only a straight stitch. But we shall see how long the material of the Dollar Tree Laundry bag holds up to the abuse of Red Wrigglers.

Step 7: Some Finished Vermicompost

I thought I'd update to show you the result of my worms' effort. You can see I am holding a handful of finished worm castings. This has been sifted with a metal strainer similar to what you find for spices or tea. It's very dry and flaky but still holds moisture. I sifted out the baby worms and cocoons to put back into the bag. After a short two months I was able to collect two sandwich bags worth of finished worm castings.

Note on storage: I don't know the best way to store castings. I put them into the sandwich bag, but they still had enough moisture for fungus to grow, so I know it's alive but it looks creepy seeing mycelium running through the bag! LOL. I don't know if drying it would defeat the living aspect of it so I'll just have to stay creeped out till I use it up.
Update 2016 : Durability. I made this project on a lark after seeing a fabric flow through bag, plus being on a budget. This cheap fabric worm bin lasted 2 years, and I was pretty mean to it. At first it stayed in my kitchen, but the second year I put it outside on my back porch and it eventually started turning to dust! the only thing left was the zipper strip. LOL. Now, for a reference, the very first image was a red laundry bag I'd bought at the same time that I never used, and despite not being used, it also turned to dust around the same time. This just tells me that while these dollar store bags are sturdy enough to hold laundry and even compost when newly made, they are not durable fabrics for long term use. I'd say 2 years is a pretty good run for cheap woven plastic. But if you want a longer term solution, I'd invest in some actual fabric cloth like polyester felt, non-organic canvas or shade cloth or patio furniture fabric; anything that will not naturally rot and has a strong open breathable weave. I'm planning to recreate this with one of the above mentioned fabrics. I'm gonna recycle that zipper strip and see what I can do.

Thanks for visiting.

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    11 Discussions


    6 years ago on Introduction

    Very nice instructions and idea - thanks!

    The mycelium is good for plant roots, so they're a plus. The finished castings can use air, but shouldn't get dried out or the beneficial microbes will die.


    Reply 6 years ago on Introduction

    Thanks for the comment. I believe if it's humid enough for the worms to keep working it, then it's probably still okay. I've been delightfully surprised at how dry a medium the worms will still stay in. I expect them to migrate inward and upward but what I thought was too dry was apparently still just right for some of the worms. So I'm letting them be the judges, though I prefer to air on the side of less dry than too dry!


    Question 1 year ago

    Did you ever make one out of canvas? Trying to make a bamboo stand for the Worm Inn Mega.


    Question 1 year ago on Step 7

    Thanks for these great instructions and for following up on how it worked out for you! I have been wanting to try this out too, and would prefer to make my own so that it meets my requirements (and budget, haha!)

    Although I have one question that doesn't seem to be answered on any website/youtube video I've visited... How do you prevent the worms from falling out of the bottom when you harvest the castings? I thought the idea behind these bags is that the worms are not as disturbed as with other methods, because they're able to stay close to the surface the whole time.


    Answer 1 year ago

    Thank you for your comment.

    You are right, the worms DO stay close to the surface, and that is how you prevent the worms from falling out of the bottom. They self migrate through the medium to the top of the bag as the food and moisture in the bottom is consumed and evaporates. It's a wide margin from the bottom to the top and red wrigglers prefer the top most layers by their nature. By the time it got that far down the worms were no longer interested and had migrated much farther up the bag, looking for moisture, space and fresh food.

    What falls out of the bottom is castings that have very little if any recognizable vegetation or bedding, is drier, more crumbly and easily knocked loose by tapping. I'd massage the bag a bit to see if there were more wet castings that were still sticking higher up. The massaging helped work things downward on top of gravity just pulling down in general.Once it stopped falling out on it's own or started showing bits of bedding, I stopped collecting. sometimes I might collect until I see an actual worm or unfinished bedding ( newspaper), but I rarely ever saw an adult worm in the bottom but often found egg cases. You can choose to pick the eggs out and add them back to the bag, or leave them in to hatch in whatever garden space you use.

    I just bought another two $1 laundry bags to recreate this. I know I should use something more durable, but I'm in a pinch, and It will be good practice to make it again with any edits or improvements before making one with a more permanent fabric.

    Good Luck to you.

    I am trying the same thing but cannot find the corner pieces anywhere ! Finally wound up using wood instead of PVC - am going to paint it red before assembling. Will put up photos when done.

    Great idea !


    Reply 6 years ago on Introduction

    I look forward to seeing your photos.

    Dr. dB
    Dr. dB

    6 years ago on Step 6

    Red Wigglers? The "Cadillac of worms"?


    Reply 6 years ago on Step 6

    Exactly! They are surface feeders and work really well in bins.


    7 years ago on Introduction

    Nice work! I really dig the PVC frame, and I hope your worms recognize how lucky they are to reside in such luxurious housing.


    Reply 7 years ago on Introduction

    Thanks. I also hope the same as well as hoping they don't mind their new bin guests who will be arriving in 2 days Via UPSP! Purple is a really Luxurious for a worm bag, don'cha think!