Compost in a Bag:
Raising Red Worms for Nutrient-Dense Soil

By Dan Corbin

Special thanks to Dan Corbin, owner of the Wisconsin Worm Farm, for sending us this informative article.

1.  Obtain a large feed or seed sack from an agricultural store or garden store.  The sack is of the polypropylene/plastic stranded variety. A sand bag is of this type of material. The sack will allow air and water to pass through with ease.  Air flow is essential in keeping a good supply of air to constantly pass in and around the contents of the bag.

2.  The worm bedding should be made up of Canadian Peat Moss (if possible)?  Mix the peat moss with water. The peat moss/water mixture should be such that no water would ring out of the mixture-just damp. (Editor’s note: Peat moss was not readily recognized as unsustainable in 2014 when this article was written. We now recommend cocopete as it is a little better)

3.  The amount of peat moss used would be dependent on the pounds of worms added to the mixture.  I generally use a 2 to 1 ratio:  two pounds of peat moss (damp) to one pound of worms.  Once the proper ratio is determined, you are now ready to add the worms to the mixture.

4.  Four to five pounds of worms can easily be added to each bag.  This is a good number of pounds for future ease of maintenance.

5.  The worm sack is now ready to hang on some type of hook, up off the floor.  It is very important that no part of the bag touch the floor, rather, air flow surrounds the bag completely.

6.  Worm food that is easily added is:  Decomposing waste fruit from the local grocery store.  Store the waste fruit in five gallon buckets with lids.  Use the fruit only after it begins to decompose.  Add the waste fruit in small, thin slices to each bag.  Thin slices are easily consumed by the worms. Do not add any more decomposing fruit until the previous fed fruit is eaten by the worms. Check every couple of day to see if the waste fruit has been completely consumed by the worms.  Only when the food is gone do you add more food!  Too much food in the bags can cause the bedding to become acidic, and this can kill the worms.

7.  The ongoing maintenance of the worm bags is the key to the successful raising of red worms.  Here are the essential steps to maintain your worms in the bags.

a. Once per week, empty each of your bags onto a flat surface.  Place a light over the contents of the bags, thus causing the worms to go down into the bedding.

b. Take a flat piece of wood, to be used as a ‘scraper’, and scrape the top few inches of black bedding off and save these worm castings into a separate container. Wait ten minutes, until the worms go down further into the bedding, then repeat the scraping of the top few inches of bedding off, and wait until the worms go down again – just repeat this process until you have most of the black, rich worm castings removed.

c. Add new peat moss in a container and mix with water until the bedding is only slightly moist.  You really don’t need to add water to the dry peat moss, if you are adding damp waste, decomposed fruit.  The decomposed fruit has enough water in it.  Now add this mixture of peat/water to the bags that you removed your worm castings from.

d. Wait one day after you made up the new mixture for your beds, then feed the worms with the decomposing waste fruit in small amounts.

8.  Add a handful of very fine sand once in a while.  Worms need grit to help in digesting their food.