Vermicompost Resource Guide

Red Wigglers – Eisenia fetida

Optimal temperature – 60-70 F

Vermicomposting is a form of Cold Composting

Nitrogen Sources = food scrapes
Carbon Sources = paper, cardboard, anything aged and brown from the garden ie – leaves *NO PESTICIDES

Totes, Bins, Containers – and Sizes:
There are a lot of worm bins on the market that are really nice to look at and make great homes for your worms.  It is really just a matter of preference on which style is best for you.
Plastic tote bins also work fine and I recommend because of the cost savings.
Standard size for 1000 worms is approx 20” l x 14”w x 14” d or anything larger.
Your bin should have a lid to help the worms shelter from the light.  You can also use an old towel or sheet to cover.
Several ¼”  holes should be drilled all around the upper sides of the bin for air exchange. 
¼” hole should be drilled in one bottom corner of the bid as an emergency drain in case too much water is added.

What is bedding?
Worms not only recycle food scrapes but they also help by recycling paper products.  Bedding is basically newspaper, brown paper, paper products, shredder paper, or any kind of paper you have available  and cardboard that is torn into strips – then completely saturated with water and wrung out like a sponge.  Do not use glossy papers or paper/cardboard with tape, glues, wax coatings, etc.   Ink is fine and will not harm the worms.
I like to fill my bins about ½ to ¾ full of bedding.  I recommend using ¾ paper and ¼ cardboard.
Adding new bedding:
As the worms convert the food waste to compost the bedding settles and becomes more and more like a dark, rich humus.  At this point new bedding may be added on top of the initial bedding, provided there is enough room in the bin.  Follow the detailed instructions for preparing the worm bin and add on top of the existing bedding.
Changing the bedding:
Again, as the worms convert the food waste to humus a time will come when the bin needs to be emptied and started over (every 3-6 months).  It is easiest to dump the entire bin out onto a tarp and create several small mounds of the humus.  The worms like it dark and will burrow down so it is easier to find them in small mounds rather than one large mound.
Prepare the bin with fresh bedding.  Sort out as many worms as you can and add them to fresh bedding in the emptied bin.  The humus/compost may then be used directly in gardens/plants or made into compost tea for a foliar application. 
If you don’t want to do this step you may simply put the humus, worms and all, into an outdoor compost bin or spread it all around a garden.  The worms will die if the weather is too cold but you can always buy more worms when you’re ready and start the whole process over again.

PREPARING THE WORM BIN* - using the Plastic Tote bin

  • Fill worm bin approximately ½ - 2/3 full of prepared bedding
  • Push aside the top 4" of bedding and sprinkle 1-2 TBSP of sand or crushed up leaves (not exposed to pesticides).  It is very important to add sand or leaves to your bin…worms have gizzards instead of teeth and need the grit to chew their food.
  • Redistribute the bedding over the compost/sand mixture
  • Add your new or existing worms to the prepared bin including the peat moss that comes in the bag


When adding new worms to a bin or changing the bedding (every 3-6 months) – you should wait a few days before the first feeding.
The following items may be given to the worms at a depth of approximately 4 inches below the surface.  Visually divide your bin into 4 quadrants “corners”.   It is recommended that the food waste be chopped up or broken into small pieces and added to one “corner” of the bin.   The next time you feed, the food should be placed in the next “corner”.   This pattern is followed until an entire grid has been used for food distribution.  Once the grid is completed the food is added to the first original “corner” and the pattern continues.  The food should be fresh not moldy and please avoid fats, oils, dressings, butter etc.  The following food items are acceptable:

  1. All fresh fruits and vegetables; ends, skins, cores, seeds, scraps (minimal amounts of citrus and high acid foods)
  2. Coffee grounds and filters
  3. Tea bags (even those with high tannin levels) – remove staple
  4. Small amounts of eggshells (rinsed well, dried, and crushed)
  5. Onions and garlic are controversial, I do not recommend
  6. BROWN Leaves and BROWN grass/garden clippings (pesticide free only)  *Carbon

Begin by feeding the worms about 1 cup of food two–three times each week.  Be sure to look at the previous feeding location to see how much, if any, food is remaining.  As time goes on the worms should multiply and the amount of food may need to increase. There will be some trial and error in the beginning.  If in doubt it is preferable to give too little food then too much.  If there is not enough food the worms will eat the paper which is perfectly fine.


The worms need a moist environment as they breathe through their skin.  Check the bedding weekly for moisture, it should feel like a wrung out sponge or washcloth.  If it feels dry sprinkle water over the entire area in order to create moist bedding.  Start small and add more as needed.


Using Vermi Compost also known as Worm Castings

Unfortunately there are no application rates available

Concentrations as low as 5% can significantly affect plants growth and yield
Very high concentrations can decrease germination, but tend to increase eventual plant growth

Small amounts goes a long way.  
Direct –
Castings can be added to indoor plants, outdoor plants, gardens, and lawns as a soil amendment/enhancement/organic matter.  It is so rich in nutrient only a small amount is needed.  Store unused castings in breathable bag, not zip lock.

  1. Use as a top dressing by adding small amounts to the top surface of the plant, no need to mix in.
  2. Turn into top 2-3” of soil  
  3. 5-10% can be added to a seed starting mix for added nutrient and seed protection.  *Do not start seeds or plant in 100% vermicompost or any compost for that matter.  It is high in nutrient but does not have water holding capacity that seedlings require.   High amounts of castings can also affect germination.   I personally use 1-2 lb in 4’x 4’ raised garden bed, adding as each crop is replanted

Compost Tea –
Castings can be used in a vermicompost tea for use as a foliar application.  Plants are able to use these nutrients immediately. 
Does not burn even with growing under lights.  Teas can be used until run off is reached.

Ingredients and Supplies

  • 5 gallon bucket - Clean
  • Un-Chlorinated water (either rainwater, pond or if tap let sit for at least 24 hours)
  • 1 cup of worm castings
  • ¼ cup Unsulphured molasses – food for the microbes
  • ¼ cup Kelp (optional) - to enhance beneficial fungal growth
  • 1 compost tea bag or nylon stocking
  • air pump * see note below
  • plastic watering can or backpack sprayer (one that has never been used for chemical applications)
  • * Air Pump - An aquarium air pump and stone work OK.  You want to create a rolling boil as opposed to tiny bubbles.  They do make home compost tea brewers that create the bubbles as well as agitation from a rotating paddle, I highly recommend.  Some sources suggest using a high-pressure (3.9 psi), high-volume air pump (17 gallons per minute). Avoid using air compressors as they can damage microorganisms.

How to Make Compost Tea   (source:  Mother Earth)
Compost tea is basically a super concentrate of the worm castings.   The whole goal is getting the microbes to populate like crazy  - ie microscopics on steroids.  And because it is already in a water soluble form the plants/soils can immediately take it in. 
1. Fill a bucket with non-chlorinated water. Water temperature is ideally between 55-80F. If using tap water, leave it sitting and uncovered for 24 hours to off-gas any chlorine.
2. Put the air stone in the bottom of the bucket, attach the air pump and let it start to bubble. Make sure there is enough oxygen and agitation moving through your liquid; if not, get a more powerful pump or move to the gang valve and three-bubbler approach.
4. Put worm castings in the stocking or tea bag, tie off the end and suspend it in the water.
5. Add the molasses and kelp
6. Let the whole brew bubble for 24 hours and for no longer than 36 hours. After 36 hours, if the tea received insufficient oxygen or too much food, anaerobic organisms will overcome the beneficial aerobic organisms. It will be obvious if the tea went anaerobic, because it will stink! If that has happened, pour it out away from garden plants and start over.
7. Pour the mixture through a strainer to remove large debris so that it doesn’t clog your sprayer or watering can.  *sprayers and watering cans should be plastic
8.  The tea should be used within 4 hours after taking the bubbler out; as the microbes will begin to die after this time.
9. Make sure to clean your bucket and pump (do not use anti-bacterial soaps) for your next round of tea

Egg or Cocoon
23 days to mature from golden yellow to dark red.  Lemon-shaped



Near Adult
Lacking reproductive band - Clitellum

6 weeks from egg to adult

Worms and bins should be inspected every once in awhile – looking for all different size worms from juvenile to adult.  Also look for eggs.  These findings indicate a healthy environment.
Bins should be emptied every 3-6 months.



  1. Smelly bin?  Typically a sign of too much food, especially food high in Nitrogen (usually “green” food).  ​Reduce the amount of food given and aim for more carbon based food (dried leaves or shredded paper)  Bins should have earthy smell similar to damp soil.
  2. Worms trying to escape from the bin?  Usually indicates there is too much moisture.  If the bedding is too wet there won’t be enough air pockets and the worms need to breathe oxygen just like us.  Wring out heavily saturated bedding and/or mix in enough dry, shredded paper to absorb excess moisture.  You could also very gently fluff the bedding
  3. Dry bedding, can’t find many live worms?  Usually a sign of too little water.  The bedding should feel moist, like a wrung out sponge or washcloth -  Add more water, a little at a time, to create a moist environment
  4. Dead worms?  Worms naturally live for 4 years.  Healthy bins are contently going through full life cycles from egg to death.  Typically upon death the worms high moisture content is lost rapidly and and they are hard to find.  If, however you are noticing lots of dead              worms in your bin most of the time this is attributed to extremely high temperatures.  Remember inside the bin temperatures can exceed outside temps.and should not go above 70 degrees.
  5. Fruit Flies?  These types of flies lay eggs on exposed food and moist surfaces.  With that said occasionally add a top layer of dry shredded paper.  Also, good to decrease amount of food.
  6. Odor?   Most likely too much water and not enough oxygen causes anaerobic environment.   You want to avoid liquid visible in the bottom of the bin.  Gently aerate by turning the bedding while adding in dry bedding to absorb some of the excess moisture.  Also may help to leave lid cracked open for awhile.
  7. Mold?  This is a sign of overfeeding
  8. Maggots?  Although decomposers as well if they are bothersome you can soak a piece of stale bread in milk then set on surface of bedding overnight.  In the morning the maggots should have gathered on the bread for you to dispose.
  9. What happens if I don’t have the time to change the bedding in 3-6 months?  The purpose of changing the bedding is to remove the castings for use in your garden/plants.  If you don’t change it the worm bedding it starts to get pretty dense and the worms will not produce their optimal output.  It is really not the end of the world…it will just slow down the process they are capable of.
  10. Will the worms just keep multiplying and need a bigger bin?                Once your worms fill their space they will multiply less by laying fewer eggs and controlling their populations naturally.  If you feel you have too many you can always add them directly to your garden/plants.  They will not, however, survive swings in temperatures but will add organic matter as they decompose. 
  11. Can I keep my worm bin outside?  The worms should be kept around 60-70F.  If your climate is cool and shady it should be fine.  Keep in mind – in a closed bin the temperature will exceed the outdoor temperature.  The only other draw back is sometimes “other” decomposeres and insects ie – spiders, centipedes, ants, etc will freely enter your bin while outdoors and may freely exit your bin when indoors.
  12.  Is vermicompost tea safe?  YES!  Vermicompost tea is completely safe to make and use.  There is some controversy regarding compost tea NOT vermicompost tea.  When brewing any kind of tea made of compost the outcome is to increase the microbe population by 10 fold by adding the "food" - molasses.  The problem comes when "hot" compost NOT to be confused with "cold" Vermicompost  is made incorrectly and does not get hot enough to kill bad bacteria like e.coli which also multiples to dangerous levels when brewing the compost tea.  Vermicompost is a cold compost and since NO animal products or manures are used the likelihood e.coli presence is very very limited if not none.  

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