Side Effects of Fertilizing with Worm Compost

One of the fun things about running a worm composting system is the (pleasant) surprises that greet us when we open the bin to add more kitchen scraps.  The innards from that cantaloupe we put in there three weeks ago?  All 800 seeds decided to sprout at the same time.  That apple core from two days ago?  Completely gone!  Herds of springtails stampeding across the open plains of finished castings!  Brushing off the top half-inch of castings to be greeted by a solid mass of happy, healthy Eisenia foetida.  (They look happy to us, anyway.)  It never gets old.

But the surprises don't stop there!  Lots of seeds that don't sprout in the worm bin proper are still viable.  We found that out last week, which was conveniently enough, a couple weeks after we mixed the crop of castings from over the winter into the square foot gardens on the decks.  Evidently, we had a very fertile cucumber in there.

All we planted was the broccoli, but we have a stochastically distributed crop of cucumbers and an apple tree as well!

In the past, most of the things that have sprouted from the worm castings have done so in the bin itself, and we haven't had to worry too much about using the vermicompost in the garden.  Don't get us wrong--plenty of things have sprouted--tomatoes, peppers, potatoes, melons, carrot tops, avocado pits, mulberry trees, and apple trees (the biggest one is almost three feet tall now!).  But these cukes caught us off guard.  We'll probably have to pull 'em to make room for the lettuce.

A quick search on the internets reveals that many other vermiculturers have had similar experiences--often with unwanted seeds that sprout from their seed-starting mix!  A few mentioned that one way to get around this problem is to expose the vermicompost to light for a few weeks before planting anything in them--that way all the seeds sprout that are going to, and it's possible to remove them without damaging the desired plants.  It seems that the most foolproof way would be to mix the vermicompost in with the dirt and expose the mixture to light for a few weeks.  Since we haven't planted anything but the broccoli yet, it turns out that this is pretty much exactly what we did, (although we did it accidentally), and it looks like it worked!  Now we just have to go pluck out all the cucumber seedlings.

Have you had any fun surprises from your worm bin?  Figured out a good way to get seeds out of the vermicompost?  Tell us about it in the comments section below!

Book Review: Worms Eat My Garbage - Mary Appelhof

One of the easiest ways to responsibly process food waste if you have limited real estate (e.g., an apartment), is with vermiculture, or growing composting worms.  We've been culturing de vermi's for about six years, and from the beginning we've been referring to Mary Appelhof's Worms Eat My Garbage -- a great resource for rookie wormkeepers.  We got an old paperback edition online, and found it to be a quick and enjoyable read.  Although it's only about 150 pages long, Appelhof covers really everything you need to know to get started with a vermicompost system (or 'worm bin' if you're talking to people who aren't grossed out by Annelida species).

Apelhof makes the first page a checklist for everything you need to do to grow worms and reap the benefits of their hard work--a twelve-step program leading to minimal food waste, worm castings for your garden, and worms you can sell, trade, or put in your aquaponic system.  The chapters are written essentially as a set of answers to the fourteen most frequently asked questions by beginning vermiculturalists.  Those questions are (with how we answered those questions in our own case in parentheses),

• What should I call it? (worm bin.)
• Where should I put it? (in the living room.)
• What container should I use? (plastic totes, for now.)
• What are worm beddings? (shredded newspaper.)
• What kind of worms should I use? (Eisenia fetida, or red wigglers)
• What is the sex life of a worm? (none of our business!--although "breeders" are the ones with the raised band)
• How many worms do I need? (probably about 1 lb. to start with)
• How do I set up my worm bin? (shred newspaper, add water, add worms, add food)
• What kind of garbage, and what do I do with it? (fruit, vegetables, bad cheese, and meat trimmings, and spoiled leftovers.)
• How do I take care of my worms? (don't let them freeze, drown, or starve--we want castings and worms! definitely don't overlook the drainage aspects.)
• What are the most commonly asked questions about worms? (for us, this list)
• What are some of the other critters in my worm bin? (springtails, mites, and occasionally fruit flies and fungus gnats)
• How do plants benefit from a worm bin? (worm castings!)
• How can I treat (food) waste as a resource? (by feeding it to worms to turn into worm castings!)

Additional sub-questions for us were, "How big should it be?," "What ratio of water-to-bedding should I use?," and "How can I get rid of fruit flies when they show up?"  Appelhof addresses each of these in sufficient detail, but we would recommend planning for a bigger worm bin than you would normally need, if you have space for it.  That way, you have a better chance at being able to keep up with all the trimmings during canning season.

With minimal effort, simple and inexpensive vermicompost systems can be maintained without odors.  These bins reside in our living room (in the Worm Trunk sneaking into the upper right of the picture), and are generally well-behaved.  Appelhof says that for a given volume, a larger surface area is better because the worms will process the waste faster.  These two bins have handled nearly all of our food waste for more than a year (with periodic harvesting of castings).

 Appelhof details a few designs for making wooden bins and points out a few commercially available designs that were around when the book was published (we have the second edition, from 1997).  While the discussion of bin construction is good, the internet is a far more valuable source of inspiration for worm bin designs, in our opinion.  There are numerous examples of DIY "fed-batch" bin and flow-through setups, and a greater variety of commercially available systems than the book indicates.  Color photos and videos are also a big plus for the internet.  We've learned a few other things about worm bin design that will be easier to share when we cover our setup in the 'Projects' section.

However, in general, Worms Eat My Garbage is a classic book with timeless advice for beginning vermiculturalists.  Although some parts of the book are starting to become dated, Appelhof's process for getting a worm bin up and running will always work.  This book truly should be required reading for anyone considering Annelid-based agriculture or food waste disposal. 

Grinding Eggshells

"We should do something with all those eggshells," we'd been saying to each other in reference to the four dozen light brown hemispheres 'drying' around the kitchen sink.  'Drying' is a bit of a euphemism because most of them had already been dry for over a week.  But...the problem of what to do with all the eggshells is a tricky one for us.  We don't have a full-size compost pile to toss them on.  They take forever to break down in the worm bin, and if we don't crush them up beforehand, each half-shell spontaneously turns into a snake pit, except the pit is very small and the snakes are actually worms.

But it turns out that eggshells, which are almost entirely calcium carbonate (CaCO3), have a plethora of uses around the homestead, provided we can grind them up small enough.  For example, in addition to being fine for the worm bin when ground up, eggshells can:

• be used as a soil supplement to raise pH and provide calcium to plants like tomatoes and peppers, which need it for a good fruit set and to help prevent blossom-end rot.  (This one we knew)
• be used as a dietary supplement for humans, pets, or your chickens.
• be used in concrete mixes.
• be made into sidewalk chalk.
• be used in scouring powder to clean sinks and tubs (use the 'calcium carbonate' recipe).
• be used as an abrasive ingredient in homemade toothpaste.
• be used as an oil-absorbing powder for face makeup.
• be used as a garden pest repellant.
• and many more

The trick is how to get the shells ground fine enough, since some of these applications need very small particles.  Crushing them with our bare hands doesn't do it, and the mortar and pestle even makes a pretty hard time of it. Our electric food processor doesn't do too much better than the mortar and pestle, although many other people seem to have better luck with similar electronic gadgets like coffee grinders and blenders.  But, we also like non-electric methods if we can help it!  We're still working on our technique, but we came up with a process the other day that can handle our modest egg shell supply without too much trouble.

Also, it's probably a good idea to sterilize the shells before ingesting them as supplements or toothpaste.  That can be done in an oven above 250 °F or so, using leftover heat from baking something else, before or after the grinding.  See also the comment below the pictutorial.

Here they are to start.  27 eggs in total, or 54 half shells.

Put one or two shells in a mortar and grind it up with the pestle to about 1/16" pieces.  With only one or two shells, it should take 5-10 seconds. Larger loads take a lot longer.

Here's the 1/16" pieces.  If you leave them bigger, the next step doesn't work as well because the pieces make bridges and don't fall into the mill blades nicely.

Add the eggshells to a grain mill and start grinding on a fairly coarse setting.

The output should look kind of like flour.  It can help to keep the hopper fairly full, and tap it frequently to shake down the pieces.

Here it is, all done.  The 27 eggshells took about an hour to process from start to finish (not including the drying).  A little longer than we would like, but it makes a nice even product.

We got a little under a cup of ground egg shell from the 27 eggs, and we also got a good arm workout in.  The powder can be used straight away in any of the applications mentioned above, but make sure to add the right amounts!

Note that if you want to get relatively pure calcium carbonate from the eggshells, without the protein and other stuff from the membranes, you should be able to use your self-cleaning oven.  The 'clean' setting heats up to around 900 °F (500 °C), which should be enough to burn off all the carbonaceous stuff in your oven (i.e., food gunk), leaving the minerals (ash) behind.  But since eggshells are mostly mineral to begin with, the 'clean' cycle will just burn off the minor components.  We've used this same technique to clean smoke residue off pots and pans that we took camping--but don't use it on anything with wood, plastic, or nonstick components!  There's also a risk that you could burn off the seasoning from your cast iron or stoneware items, so it's best to use stainless steel vessels if you can.

What do you use egg shells for around your house?  Have you found a good way to grind them up with minimal effort? Tell us about it in the comments section below!

EDIT: The clean cycle on some ovens might not get hot enough to turn crushed eggshells into a nice white powder, so you'll have to experiment with yours if you really want the calcium carbonate.  Also, we've found it preferable to use a sheet of aluminum foil instead of a steel pot, since the clean cycle can be a little harsh on some pots and pans.