The Worm Farmer’s Handbook: A Must-Read Book for Operating at Scale

The Worm Farmer’s Handbook is a must-have book for anyone wanting to engage in mid-scale or larger vermicomposting or vermiculture for profit or non-profit purposes. This review will give a quick overview of the book, describe the structure of the chapters, and should illuminate what you should – and shouldn’t – expect from it.

Now I have to disclose that I am friends with the author, Rhonda Sherman of North Carolina State University. Rhonda hosts the annual Vermiculture Conference in Raleigh on the campus of NC State and I have gotten to know her though my attendance at the event. So if this book sucked, I honestly wouldn’t say so; I would just decline to review it in the first place.

But it’s a wonderful book, so I’m thrilled to give it a huge Urban Worm Company Thumbs Up!

Buy The Worm Farmer’s Handbook for the best price on Amazon.

First Impressions of The Worm Farmer’s Handbook

When I first got my hands on it in late 2018, I was very impressed with the look and feel of the book. It  has a surprising heaviness, thanks to the premium paper stock that reminds me of the high-quality college textbooks that I hardly ever read. The tactile characteristics of the book only add perceived value to what I consider to be excellent information inside.

image of Rhonda Sherman
Rhonda Sherman, NCSU Extension Specialist

I love the clean aesthetics of the book too. As someone who doesn’t like how most worm books feature busy, cartoony graphics, the single image of a composting worm and the simple typography gives the book a certain elegance too.

And I love the conversational prose Rhonda employs in this book. Vermicomposting and vermiculture is a jargon-heavy industry and it would be easy to take the reader down confusing esoteric rabbit holes discussing graduate-level material that is simply not needed for a reader who is exploring a scaled-up worm operation.

Rhonda makes the complicated simple, which is a hallmark of a good writer. So while the material is beyond beginner level, the book is as pleasant and easy to read as Worms Eat My Garbage.

No vermicomposting experience is necessary prior to reading this book.

Chapter 1 and Beyond: The Structure of the Worm Farmer’s Handbook

Chapter 1: Why Venture Into Vermicomposting?

It wasn’t until I finished the book that I realized – whether Rhonda meant to do it or not – that the first and last chapters make for wonderful bookends for the middle chapters.

After a short introduction, Chapter 1: Why Venture Into Vermicomposting?” provides a 101-level intro to vermicomposting and helpful synopsis of the history of the industry and the various businesses, municipalities, and institutions who have engaged – or are currently engaging in – mid- to large-scale vermicomposting and vermiculture.

She briefly describes the growing interest in worms and worm castings, or vermicast. Demand for worm castings is growing, thanks to the booming organic growing movement, bait markets, and agricultural producers who want to use worms to help recycle manures, residues, and other organic wastes.

(UWC Comment: As a more contemporary aside, awareness of needless landfill use and zero waste lifestyle choices coupled with the growth of cannabis- and hemp-related products are very worm-friendly trends that will continue to provide a tailwind to the industry.)

What’s really cool is that she whets the appetite of would-be business owners by highlighting a few entrepreneurs like Jeremiah Picard of Big Red Worms and my friend Heather Rinaldi of the Texas Worm Ranch who are everyday people making it happen in the world of worms.

Jeremiah Picard of Big Red Worms

After 9 more chapters of describing the methods, challenges, benefits, and regulatory concerns around vermicomposting and vermiculture, (which I’ll get to below), Rhonda then takes us on a virtual world tour of a who’s who of vermiculturalists and vermicomposters.

This was incredibly fun chapter to read and gives flavorful real-world examples of people employing the very principles she describes in the previous chapters.

Note: The methods of vermicomposting and vermiculture (the animal husbandry of earthworms) are different, they both fall under the umbrella of “worm farming” for the purposes of this book. Most of the material presented in The Worm Farmer’s Handbook is within the context of vermicomposting.

So this book gives you a tasty appetizer, a hearty helping of much-needed education in the middle, and a final chapter dessert of how people around the globe are leading the charge, making both money and a difference in the process. Indeed, without the final chapter, a reviewer unfamiliar with Rhonda’s experience may have described chapters 2-9 as mostly theoretical.

But Chapter 10 really puts the cherry on top for the reader who needs convincing that “Yes, I can do this!””

Chapter 2-9 of The Worm Farmer’s Handbook: What The Reader Can Expect

Chapter 2: How Vermicast Benefits Soils and Plants

There is simply a dizzying array of data to prove that vermicompost has huge effects on soils, plants, and pathogen and pest control. Relying heavily on the academic research of luminaries like Dr. Norman Arancon, Rhonda distills the data down to understandable chunks, using charts where appropriate.

Otherwise, Rhonda uses plain English to make some complicated concepts sound downright simple.

Chapter 3: Key Things to Know About Earthworms

This short chapter is a helpful refresher on earthworm basics to include:

  • a description of earthworms
  • which earthworms are suitable for vermicomposting
  • how worms reproduce
  • and what conditions need to be maintained for vermicomposting.

For beginner and expert alike, this chapter has something to offer.

Chapter 4: Planning for Success

Rhonda touches on regulatory compliance, business plans, corporate structure, and developing workflows for efficient operations, before a more fleshed-out discussion on marketing the end product. The final section titled “What to Avoid: Why Operations Fail” is a must-read list of reasons for business failure. It should be read and re-read.

Chapter 5: Designing Your Vermicomposting Setup

In this chapter, Rhonda details the various factors that a new vermicomposter will have to consider, at least one or several of which will be constraints on operational design.

Notional design for a worm farm in California produced by the Urban Worm Company

These factors include:

  • Climate
  • Local regulations and zoning
  • Existing buildings
  • Quantity of feedstocks
  • Available space
  • Funding requirements

She closes the chapter with a handy rundown on the various, methods of vermicomposting, ranging from simple wedge and windrow systems to more sophisticated continuous flow through (CFT) systems like the kind offered by Michigan SoilWorks.

Chapter 6: Vermicomposting Basics

Rhonda gives a fairly detailed worm bin startup process, explaining the importance of bedding and describing the characteristics of quality bedding. She proposes a 1-2 lb-per-square-foot worm stocking density and details the process of introducing worms to new bedding.

The last 10 pages of the chapter are dedicated to safety awareness and avoiding bodily harm which is a distinct possibility in potentially strenuous activities associated with vermicomposting and vermiculture.

Chapter 7: Earthworm Feeds and Feeding Methods

Chapter 7 is a fantastic summary of the most common feedstock options for a larger scale operation, to include food waste, animal manures, vegetable residuals, and paper sludge among others. Rhonda stresses the need to develop consistent feedstock recipes with consideration given to the carbon-to-nitrogen ratio, particle size, bulk density, homogeneity, and the presence of persistent herbicides or pathogens in certain feedstocks.

The chapter closes out with a section on precomposting feedstocks for larger scale operations and low-labor methods of applying feedstocks to large scale worm beds and bins.

Chapter 8: Monitoring Your Worm Bed Environment

Whether you’re growing worms for profit or using them to recycle your township’s organic waste, the conditions inside the worm’s habitat needs to be within parameters for moisture and temperature. pH is a less common concern.

Rhonda details these ranges and also gives us a handy troubleshooting guide for identifying when these conditions have gotten out of whack.

Jetspeed Worm Castings Harvester at the Urban Worm Company

Chapter 9: Harvesting and Post Harvest Practices

Once you’ve got finished vermicompost, your work is just beginning!

Chapter 9 of The Worm Farmer’s Handbook lists the methods of harvesting worm castings and considerations for packaging and shipping your product. Of particular importance are the restrictions on the claims you can make on the labels as this can get you in hot water with the feds or state and local regulators.

For example, you may already know that using the term “fertilizer” on your label places your product into a more heavily scrutinized category than the more vague “soil amendment” moniker. But did you know that if you mention NPK (nitrogen, phosphorous, and potassium) values on your packaging, that regulators now consider your product a fertilizer?

(Truth be told, lots of small businesses can fly under the radar for awhile, but when you start playing with the big boys and girls, the rules change.)

Chapter 9 closes out with a section on teas and aqueous extracts, a post-harvest product with immense added value from a small amount of vermicast.

Chapter 10: Vermicomposting Operations Around the World

Now we get to the fun part! Taking a tour across operations large and small in the US, Canada, Mexico, Turkey, Belgium, New Zealand, and Afghanistan (!), Rhonda gives us a glimpse of how these operators are putting to work the principles she described in Chapters 2-9.

A vermicomposting operation in Afghanistan (source

Rhonda has a little something for everyone, from the small-scale mom and pop operator with the hand-built trommel harvesters to the monsters like Francisco Niembro of Aldea Verde and Mark Purser of the Worm Farm. These guys produce in incomprehensible volumes that I like to describe as “metric buttloads.”

If you are interested in starting a worm business of any sort, but have significant restrictions on space, budget, labor, etc (See Chapter 5!), chances are that Rhonda has profiled someone in similar circumstances.

As I mentioned above, this chapter is the capstone that ties together the preceding chapters!

Final Thoughts on The Worm Farmer’s Handbook

This book is an comprehensive description of how mid- to larger-scale vermicomposting can be accomplished for businesses, schools, and institutions, not how it should be.

Simply put, this book is not a “how-to.”

Rhonda does not presume to know what will work in every situation and I’m glad she presented the material this way, because there is no one path to success and no formula to follow. I cannot replicate Mark Purser’s California-based vermicomposting operation on my property in Philadelphia.

Michigan SoilWorks CFT at WormCycle’s Detroit-area operation

Gavin Newton of Detroit-based WormCycle, who is also featured in this book, cannot pull off windrow-based vermicomposting in his climate. Zach Brooks of the Arizona Worm Farm self-funded his operation to an extent that most operators cannot.

Everybody’s situation is different.

This isn’t a snake-oily “path to riches”. Chapters 1 and 10 make it pretty clear that every vermicomposting project is different and the successes and challenges faced by one operator may not be experienced by another.

So I’m pleased to see that Rhonda shied away from offering a formulaic approach often unethically offered by unscrupulous hucksters trying to make a buck.

Whether you’re a would-be or current entrepreneur or someone looking to reduce input into the waste stream at your school or institution, you can’t start with a better book than this. And if you’re vermicomposting beyond the hobby level, but wonder if you’re missing something, this comprehensive book is not to be missed.

Way to go, Rhonda! Two thumbs up!

3 thoughts on “The Worm Farmer’s Handbook: A Must-Read Book for Operating at Scale

  1. I am interested in giving consideration to worm farming.Where can I get the book you have discribed?

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