Boulder Vermicomposting

CA Dept of Pesticide Regulation Fines Castings Producer

Via this news article, I learned that a California producer of worm castings, Worm Gold, was fined 100K by the California Department of Pesticide Regulation.  The fine was because the Worm Gold product is touted as “helping plants repel bugs”, and so should be classified as a pesticide, and thus regulated.

This is being fought as a free speech case–you can find out more here.

2 comments June 15th, 2010

Gone fishing

Folks, I’m going to take a break from the worm composting blog for a bit–I am getting married June 5 and things are a bit hectic around here.  So, please forgive the lack of new posts for a couple of weeks.

Thanks!

Add comment May 25th, 2010

The difference between compost tea and leachate

I realized that I had written this a while ago, but only published it on my newsletter, so I thought I’d post it on the blog for the world to read.

I’ve seen several inaccurate posts/articles about worm composting and in particular the uses for the liquid that often comes out of the bottom of a worm bin. This liquid is called leachate. The US Environmental Protection Agency provides us a handy definition of leachate: “Water that collects contaminants as it trickles through wastes, pesticides or fertilizers. Leaching may occur in farming areas, feedlots, and landfills, and may result in hazardous substances entering surface water, ground water, or soil.” The leachate out of the worm bin is not useful, and can be harmful. I know that some of the people I’ve interviewed have used it on their plants, judiciously.  Forest says “I would just dump [it] down the toilet if it was bad. [some of the worm leachate] had sat for a couple weeks and that didn’t have the smell anymore. And that I would mix with water and then water my plants with it.”

But there’s a difference between leachate and compost tea. Compost tea is compost mixed with oxygenated water, creating “a Petri dish: favorable conditions are made for the beneficial soil microbes, already in abundance in worm castings, to reproduce millions of times over in the water culture.” Water running out of the bottom of your worm bin may or not be favorable to these beneficial aerobic microbes. Since it runs through the bottom, it may be collecting microbes that thrive in anaerobic conditions. These microbes, called “obligate anaerobes”, use chemicals other than oxygen to respirate. According to wikipedia, “[t]he most favorable [chemical for respiration] (after oxygen) is sulfate. [Byproducts of which] most of us are familiar with as the rotten egg smell”. This water probably also contains uncomposted organic matter, which is not what you want to apply to plants; otherwise we’d just dump our scraps directly on plants.

In short, what comes out of your worm bin is called leachate and is not compost tea.  Don’t use it like compost tea.  Dispose of it (I’d probably put it back in the worm bin, myself).

4 comments May 19th, 2010

Earthworms used for coffee waste

Via Clean Technica, I found this article about the Rogers Family Company using redworms to process their coffee waste.  Apparently, coffee processing generates a fair bit of organic waste, and this was decomposing and  leaking into groundwater.

So, leveraging techniques used elsewhere, including in Selva Negra in Chiapas Mexico, they set up worm bins on their farm in Panama.  The goal?  Process 5000 tons of coffee pulp and turn that into free fertilizer for independent growers.  The company ended up with “10,000 square meters [of worm bins] filled with a billion worms”.  I asked why they chose E. Foetida, rather than one of the worms more suited to the tropics (as outlined here [PDF]); I’ll be interested to see their answer.

Talk about industrial vermicomposting!  I remember reading a while ago about ‘decompiculture’ (PDF here) which is the idea of “growing or culturing of decomposer organisms by humans”, the same way that agriculture is the growing or culturing of plants and herbivores.  Decomposers, whether redworms, bacteria or mushrooms, can help address some of our most fundamental issues of garbage management by turning waste into useful substances.  This project showcases decompiculture.

Pssst!  You should complete the cycle and vermicompost your coffee grounds.

Full press release here, and full blog post with pictures here.

2 comments May 13th, 2010

Worm Composting Article in The Boulder Weekly

I helped the author of a worm composting article in the Boulder Weekly a week or two ago, and it’s now up on their website.  From “Let Worms Eat Your Garbage” by Charmaine Getz:

Moore, a web developer who once spent two weeks in Australia as a volunteer farm worker, raised the lid and introduced me to his red wrigglers. There was a whiff of plant rot.

“I haven’t been here in a couple of months,” Moore apologized, as he hefted a bag of dead leaves into the bin. “It doesn’t smell when you give it regular attention.”

By that he meant renewing with fresh worm food and removing the compost more frequently. Still, the bin smelled less than my weekly wormless kitchen compost.

Moore pulled out a drawer near the bottom of the bin into which worm castings had fallen. The contents looked like the black gold that I buy at the garden center.

The bin yields about 10-20 pounds of compost twice a year that go to the condominium association for its community garden. Moore started another worm bin recently at the home he shares with his fiancée, Pam Sinel.

Read the whole article here.

Add comment May 6th, 2010

Interview: Redworms in an middle school

I wrote a while back about redworms in a Durango middle school.  I actually contacted the teacher there (in late March) and was able to ask her some questions about her experiences.

Dan: What piqued your interest in vermiculture?

Sharon: Actually, it was Jennifer Craig (Durango Compost) whom I met at the Farmer’s market in Durango a few years ago, and I was tired of buying expensive worm casting soil for my garden.  Now I have tea, and great compost.

D: How many bins do you have running?

S: I have one huge bin… a commercial metal bin that holds about 16 pounds of worms.  It has a heater, but it is not adequate for our cold winters (it has to be outside on the dock at school)  so I had to use rope lights wound around it with a thermal wrap over that.  It worked great; however it is now difficult to regulate the heat factor, so I am wrapping it with reflective material. Unfortunately, there is no other spot.

D: How have the kids reacted?

S: They think it is very cool!  Of course, some of them don’t want to touch the worms, but I make them, and then they are ok.  Now, since we are turning over soil in the garden, they bring the biggest earthworms they can find and are very proud of themselves.  Who can figure?

D: How have the parents reacted?

S: Great!  I am holding a workshop in April to show them how to make their own worm bins so I’ll let you know how many are really interested.

D: Is it in the classroom, or in a different space?  Is it inside?  How do you handle odors/fruit flies (if you have them)?

S: It is on the dock.  I had them in an empty room in 5 different bins, but fruit flies were an issue.  No one was patient enough to see if the neem oil would work, so we took them to the big bin, where they are not a bother.  I will be spraying neem oil soon to that bin.  The bin odor is not an issue, as we must be feeding them the right amount because it doesn’t smell bad…just earthy.

D: How much do you feed the worm bins a week?  How many worms did you start with?  Do you feed them mostly food scraps?  What do you use for bedding?

S: Right now we are feeding them about 4 lbs. of food a week, mostly raw food scraps and coffee grounds.  Our bedding is shredded paper and newspaper.  We started with 5 lbs of worms, but given our data, we think there are about 8 lbs. now.

D: How do you harvest the compost?

S: It is mechanical—a handle rotates and it comes out the bottom.  I don’t like it as well as our smaller bins (we had layers of screening with bedding and food, and they worked their way up, and mostly compost was on the bottom.

D: How much time/week do you (or your class) spend maintaining the bins?

S: We take the temperature daily and feed once a week, so no more than 10 minutes a day.  Sometimes we do data collecting which will be a class period.

D: What overall lessons are you trying to convey with the worm bins?

Add comment April 30th, 2010

Three Wrongs of Worm Bin composting

I found an article on this topic via the_worm_bin, and it’s great.  It discusses the three things you can do wrong in a worm bin: over feeding, over watering and over stimulating.  In particular, the tips to avoid overfeeding are good:

When starting a new bin, start feeding 1/4 of worms weight. Most people suggest feeding their weight. Yes, maybe later but not at the beginning. Let them get used to their new home. So if you have a pound of worms start with 1/4 pound of feed.

This is in line with some of the other feedback I’ve gotten in the past: “[f]eed your worms gently at the beginning”, but is more specific than anything else I’ve seen.

I’ve said before that keeping worms is easy, but, especially if you’re going to keep the worm bin in your house, and not in some in between space, it’s worth reviewing these tips.

Add comment April 20th, 2010

Super Market Composting Handbook

Via John Anderson, I found the Supermarket Composting Handbook (2MB pdf), produced by JFConnolly & Associates and WasteCap of Massachusetts.  This handbook, while it doesn’t mention worm composting, is a fantastic resource for anyone who is attempting to implement composting at a corporate level.  It discusses the economics of composting vs trash hauling, monitoring program success, employee training, has sample contracts and signage for employees and consumers, and in general appears to be a fantastic resource.

Here’s my favorite takeaway from the Handbook:

As waste disposal costs rise and the need to help improve our environment becomes increasingly more important, supermarket operators are looking for alternatives to reduce disposal costs through recycling more of their waste. Seventy five percent (75%) of most supermarket waste, after recycling cardboard, paper and plastics, is comprised of non-recyclable biodegradable materials including discarded food, waxed and wet cardboard, paper, renderings, soil, and plants. Recycling these wastes through composting can be a lower cost alternative to disposal and makes a lot of sense for supermarkets.

Of course, the economics for composting vs recycling vs landfilling are different for every location, but this handbook makes evaluating composting as a solution easy.

Add comment April 10th, 2010

Fort Collins Vermicomposting Workshop, Apr 11

The Rocky Mountain Sustainable Living Association is hosting a vermicomposting workship, run by none other than the Colorado Worm Man himself, John Anderson.  I found out about this via this tweet from the Front Range Permaculture Institute.  From the description:

In this workshop participants will imagine the re-use of materials and the repurposing of items into a functional and efficient organic conversion machine. Really! John will cover super simple on ground designs to elegant flow-thru concepts to keep our worm friends comfortable inside or out. John will show and tell and inspire from fifteen years of designing, constructing and using worm bins. Then we will get to work physically creating worm bins from the items and materials that have been gathered at the ReSource site. Some we will start, some we will be able to finish, and some we will sell to support non-profits.

Sounds like fun to me!

Add comment April 8th, 2010

Storing vermicompost

There was an interesting thread on the_worm_bin in March about storing vermicompost.  Vermicompost, you may recall, is the intermediate stage between feedstock (food waste, rabbit poop, etc) and castings (worm poop).  Bentley has a nice definition:

Vermicompost is really a more accurate term when it comes to the material produced in most worm composting systems. It is basically a mixture of worm castings, partially composted wastes, and any resistant materials that won’t readily break down. Really high quality vermicompost should have a high percentage of worm castings in it, but the chances of having every last bit of material in your system pass through a worm at least once is pretty slim.

I typically only remove vermicompost from my bin once or twice a year, and apply it directly to plants or planting beds, so storage is not really an issue for me.  However, I can see this being an issue, especially if you are in one of the following situations

• selling vermicompost
• producing large amounts for other purposes
• have a small bin and want to switch out the vermicompost for more feedstock

So, here are some of the solutions.

Buddy says “I store mine in a loosely covered container in a cool corner of my garage. The cover helps to keep the castings from drying out too much, but allows enough air flow so that they do not turn sour. Stored this way, they should be good for at least a year.”

Liz says “I store mine in 5 gallon buckets with holes drilled in the lids. I moisten them monthly to keep the bin active AND I top feed with a rind of somesort like watermelon and once a month when I water I lift the rind to transfer any worms.”

Allison says “Store it in any ventilated container and water it occasionally so that it doesn’t dry out completely. If it does dry out it is still good compost but not as good as if you keep it alive by keeping it aerated and moist.  BTW: When you go to use it you might find some worms have hatched out so you might want to do a final check for them; they don’t tend to like going into garden soil so its better to pick them out.”

So, it sounds like the keys to storing vermicompost are:

• keep it in a cool place
• keep it moist (but not too moist)
• keep it aerated
• remove any worms who have hatched

Anything else to think about when it comes to storing vermicompost?  Have you had any bad experiences doing so?

Add comment April 2nd, 2010