Red Wiggler Worm Castings / Vermicompost in My Hand

Vermicompost is extremely fine-grained and almost silky feeling in your hands. This is because worm compost is made up of individual worm castings (pieces of worm poop), each of which is a bit bigger than a grain of sand. It’s amazing to look at a bucket full of red wiggler worm castings and realize that nearly every single piece has passed through a worm at least once!  You certainly don’t recognize the original food scraps  — with the occasional exception of pieces of eggshell, hard seeds, etc. that the red wiggler worms can’t digest.

Red Wiggler Worm Castings / Vermicompost

Many gardeners consider worm castings to be the “black gold” of compost because of this fine texture, and also the fact that vermicompost may have more nutrients than traditional or “hot” compost.  A definite advantage is that each casting is surrounded by a thin mucous layer, which essentially makes them like tiny time-release nutrient capsules!

Red Wiggler Worm Castings / Vermicompost (with pumpkin seed)

The worm castings pictured have been “cured” using the process described in the excellent book
Recycle With Earthworms: The Red Wiggler Connection (by Shelley Grossman and Toby Weitzel).  “Curing” vermicompost  means letting it sit in a bucket for a couple of weeks after harvest, allowing any worms you missed while harvesting or newly-emerged babies to finish off any  food which remains.  The result is lighter, fluffier, and more completely broken down than “raw” worm castings.  You definitely don’t need to cure your compost, but it’s a nice extra step if you have the time.  People who saw our vermicompost at a Farmers Market last summer were amazed by the texture (we were, too!)

Red Wiggler Worm Castings / Vermicompost Closeup (with undigested pumpkin seed and piece of eggshell)

How to use your newly-created vermicompost?  Worm castings are excellent as an extra nutrient boost added to gardens, for indoor plants, or anywhere else you’re growing.  We used several gallons of worm castings as part of our seed starting mix this spring.  We often see melon, cucumber, and even peach pits sprouting in our worm bins.  I’ve heard (and believe) that worm castings may contain beneficial microbes which help prevent fungus from killing off newly-emerged seedlings.

Another use of worm castings to make “compost tea” or “worm tea”, a liquid mixture of worm castings and water that can be poured on your plants as fertilizer.   Whether you choose to use it dry or as worm tea, your plants will thank you!

Happy worm farming (and vermicompost making)!

There are tons of guides online about how to compost with worms.  Just do a Google search, and you’ll be overwhelmed with pages of instructions for keeping worms.  The quality of these instructions varies greatly, and you’ll often find conflicting advice.  (Example: Is it okay to add meat and dairy to a worm bin or not?  Our answer:  Yes, but only small amounts at a time.)

If you’ve done your research on red wiggler compost worms but still have questions, feel free to ask them in the comments section below.  We’ve been composting with red wiggler worms for over 5 years, and are happy to share our knowledge.  No need to learn it all by trial and error!

We’ll try to answer your questions as they come in, and use your questions as inspiration as we add pages to our site on how to compost with worms.  Ask away!

Hemlock compost worm bin from the side - 38" long

For the past 4 years or so, I’ve been building my compost worm bins out of wood, and making them large enough that there’s plenty of room to bury the food scraps and for the worms to move around as needed.  My preferred material now is rough-sawn hemlock, but any wood that is not chemically treated will work fine.  The wood will decompose slowly, but you should get at least 5 years out of it before it rots too much to be usable as a compost worm bin (and then you can still re-use it as a flower or herb bed).

Hemlock compost worm bin from the end - 14" wide

The size of compost worm bin I recommend (and offer for sale when I’m at a Farmers Market) is 38″ long X 14″ wide X 12″ deep.  That provides inside dimensions of 36″ X 12″, or exactly 3 square feet.  Three square feet of surface area is sufficient for 3-4 lbs of red wiggler compost worms — so if you start with 1-2 lbs, you’ve got room for the colony to expand.  It’s always better to have a compost worm bin that’s a bit too large for your current needs than a bit too small.  The bigger the bin is, the better it keeps at the correct moisture level and the less often you need to empty it.

Hemlock compost worm bin from inside - 11" deep

There’s no need to ensure that the joints of the bin are 100% tight and worm-proof.  As long as you maintain good conditions in the bin, the red wiggler worms would much prefer to stay in the moist, food-filled inside than to venture out.  I also don’t use a tight-fitting lid — I usually just lay a piece of cardboard over the top of the compost worm bedding to keep moisture in and light out.  I’ve never had a problem with compost worms escaping from a setup like this.

It’s practically impossible to completely worm-proof a container, anyway.  Even plastic containers with snap-on lids have enough gap around the lid for the worms to escape.  All but the largest red wiggler compost worms can even squeeze through standard window screen.  It’s far better to concentrate on creating good living conditions for your red wigglers than to try to create a “cage” they can’t escape from.

It’s pretty easy and inexpensive to build your own bin if you’re fairly handy.  I also offer them for sale sometimes — contact us for more information.

Happy worm farming!

Red Wiggler Compost Worm Egg/Cocoon in Worm Bin

When red wiggler egg cocoons are first laid they’re a rather pale yellow color which really stands out against the dark compost.  As they mature, they change to more of a reddish-brown that’s a bit more difficult to spot.

Red Wiggler Compost Worm Egg/Cocoon on My Finger

If you’re seeing red wiggler eggs in your worm bin — congratulations!  You’re providing a good enough environment for your compost worms that they’re able to breed.  Speaking from experience, it’s pretty exciting when you first see eggs/cocoons in your worm bin.  At that point, you’re well on your way to increasing your worm herd.

It’s sometimes possible to buy red wiggler compost worm eggs directly online, but it’s much more common to buy live compost worms.   If you find red wiggler cocoons in with your worms when you buy them, great!  That just means you’ve gotten a lot of potential baby worms to grow up in your worm bin.

Since I took this photo, the temperature has actually climbed into the 150′s, perhaps even 160′s.  Wow!

People often ask me if they can add worms to a traditional compost bin/pile.  I think this certainly shows that you can only add worms to compost if they have cooler places to hide, or if you manage the pile/bin very passively (throw scraps on every once in a while, don’t turn it regularly).  Worms will be very happy to hang around the fringes of a hot compost pile (and finish the compost to beautiful vermicompost), but they can’t survive 145+ degrees directly in the center.  In this large bin, they could easily escape to the other, cooler end.

I’m going to experiment more with using hot composting as a way of “pre-processing” scraps to give to the worms.  Worms can’t eat food scraps directly, but rather need to wait for bacteria/fungi to start the process.  A bit of hot composting at the beginning should help produce a half-finished compost the worms can finish up much more quickly.

Here’s a good article from the USDA about the various composting options, including “hot composting”, “cold composting” and vermicomposting: http://www.nrcs.usda.gov/FEATURE/backyard/compost.html

Scaling It Back a Bit
After last summer’s experiment with selling red wiggler compost worms and vermicompost at the farmers market, we decided to scale back our hobby business and return it to just a hobby.  We believe strongly in compost worms as a way to turn food scraps to rich compost, but the market we were at was just too small for what is still a very niche product.  While maybe one out of every two people at a farmers market are there to buy produce, perhaps 1 in 50 would be interested in buying compost worms or vermicompost.  I think only a large market like the Saturday Burlington or Montpelier farmers markets would really work out.

Worms Survived a Vermont Winter Outdoors!
Because we already had a significant humidity/mold issue going in our basement (from moisture, not worms), we decided not to move our large compost worm bins into the basement for the winter.  Small 2-4 square ft., family-sized worm bins like most people have would have been fine, but we had two bins that are 12+ square feet each.

Outdoor compost worm bin, 6 ft. x 2 ft.

Without a garage or other semi-heated space to put them in, we were forced to just overwinter our worms outdoors.  I overturned the large bins so that the compost would be directly in contact with the ground to moderate the temperature a bit, and put the wooden bins overtop to provide some shelter.  I really didn’t expect the worms to make it through (conventional wisdom says red wigglers can’t handle freezing temperatures).  There they sat under the snow all winter, and we even had temperatures as low as -30F a few January/February nights .

In early March when I went back and checked on them, I was really surprised to find live worms in the parts of the compost that wasn’t frozen!  In April after temperatures weren’t so frigid, I set the bins back upright and re-filled them with the worms and compost.  There definitely weren’t as many as we had last Fall (many could have simply escaped to the ground and leaf litter), but there were many alive.  I soon started finding lots of worm cocoons, so they’re obviously breeding again.

Worm Compost as Seed Starter
When we were starting seeds for our vegetable garden in March, we used vermicompost as perhaps 1/4 of our soil-less mix.  The bacteria and enzymes in worm compost are supposed to beneficial in suppressing fungus when germinating seeds, in addition to being a great nutrient source. Our seedlings all got off to a great start, so maybe we can credit the vermicompost for some of that!

Summer 2009 Plans for Wormy Acres
We won’t be regularly attending the Burlington South End Farmers Market this summer, but may make a few “guest” appearances.  We’re mostly scaling our vermicomposting back to a “hobby” this summer, with the goal of producing a lot of worm compost to add to our gardens.

However, there’s still a lot of interest in vermicomposting in Vermont, and we might do a bulk order from a worm wholesaler a few times this summer in order to sell worms at a reasonable price.  Buying worms in 10lb or greater quantities lets us sell them at $25/lb for a small profit, which is at least $5/lb less than other online mail-order sources.  Please contact us on our contact page for more information.

Thanks for visiting, and happy summer worm farming!

Since we’re still ramping up our vermicomposting, we had to buy four trailer loads of Intervale compost for our gardens (not sure we’ll ever get big enough to sell compost by the cubic yard).  There’s an amazing difference in how fine and completely-decomposed vermicompost is when compared to traditional compost.  I’ll post some photos soon, or come check us out at the Burlington South End Farmers Market Wednesday afternoons!

I visited my outdoor bins to find the redworms wandering every which way.  I even caught a couple about 2 feet up a tree!  They were on their way down by the time I snapped a photo, but still…  Worms in trees?

Like I said, compost worms generally only wander off when they’re first placed in new bedding, or if conditions in the bin get bad (overfeeding, etc.)  A partial solution to make them stay put while they’re first adjusting is to keep a light over the bins.  Like most worms, Eisenia fetida avoid light when they can.  I rigged up a makeshift dusk-to-dawn light over the bin, and the problem was mostly solved.

So… serious lesson (re-)learned here.  When you first set up a bin, it’s a very good idea to keep a light over it for a few days.  Once the compost worms have settled into to their work of vermicomposting, they generally stay put.  But if the bedding is new and the night is moist, they might go for a wander…