Permaculture – my final thoughts

We’ve had some good, vigorous discussion about permaculture, specifically around the book Gaia’s Garden.  I’ve pointed out some problems with the author’s understanding of relevant plant and soil sciences and will wrap up this week with a look at the glossary and bibliography.


The glossary contains a number of scientific-sounding words and phrases with unscientific definitions; for example:

“Buffer plants: Plants placed between guilds or between allelopathic species. They should be compatible with the trees in each guild and should have a positive effect on one or both of the guilds to be linked.” (“Buffer plants” is a phrase legitimately used in ecological restoration where plantings separate wetlands or other natural areas from human activity.)

“Guild: A harmoniously interwoven group of plants and animals, often centered around one major species, that benefits humans while creating habitat.” (The term “guild” is ecological and refers to groups of species that exploit the same types of resources.  It has been hijacked and redefined for permaculture.)

“Narcissistic: Plants that thrive on the leaf litter of members of their own family, such as the Solanaceae, or nightshade family.” (In this case, this is an unscientific term given a scientific-sounding – but nonsensical – definition.)

“Polycultures: Dynamic, self-organizing plant communities composed of several to many species.” (Polyculture is an agricultural term referring to the planting of multiple crops. It’s a cultural strategy in Integrated Pest Management.)

“Sectors: Areas where outside energies such as wind, sun, fire and so forth enter a site. These energies can be mitigated, captured, or otherwise influenced by placement of elements in the design.”


There are only two books I would consider scientific; one soils textbook from 1996 and the other is Odum’s classic text Fundamentals of Ecology (1971). I’m disappointed in how scarce and dated these references are, given the wealth of more recent articles and books that are both relevant to urban gardens and scientifically sound.

The bibliography also includes many books on design and I’m not including them in this critique. Of those that remain, the bulk are nonscientific and in many cases pseudoscientific. Examples of the latter include The Albrecht Papers (Albrecht, 1996), Weeds and What They Tell (Pfeiffer, 1981).

And this last criticism embodies what permeates much of Gaia’s Garden: pseudoscience. In the glossary, we see scientific-sounding terms or definitions that are ultimately meaningless or incorrect. Furthermore, we see scientifically legitimate terms such as guild used incorrectly. Both of these practices are characteristics of a pseudoscience.

I think this is unfortunate. I’ve mentioned before that I agree with much of the philosophy behind permaculture. But dressing up this philosophy as science both misleads nonexperts and alienates scientists.

So here’s a challenge – why not write a new book on permaculture and collaborate with a scientist? (I know a few who are writers!)

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Linda Chalker-Scott


34 thoughts on “Permaculture – my final thoughts”

  1. haven’t seen the book WILD URBAN PLANTS OF THE NORTHEAST, yet, and I don’t see use of the word “Permaculture” in the reviews I’ve read, so this may be off-base, or off-topic, but this book does seem sympathetic to the permaculture idea discussed earlier, that Invasives aren’t invasive in certain environments; they are now the natives of urban areas, or perhaps that’s just the spin that the reviewers are putting on it.

    Some discussion: Don’t Sweat the Invasion and This Is Not a Weed

    Our Extension Office recently received a PR email on the book:

    Like our landmark publication Weeds of the Northeast, which you already know and use, this guide will become a standard on your bookshelf. It will be of key interest to anyone with a desire to identify and understand the wild plants that inhabit our built environments.

    Our cities and towns may seem harsh and unwelcoming to vegetation, with their pavement, reflected heat, polluted air and contaminated soil, but there are a number of plants that manage to grow spontaneously in sidewalk cracks and roadside meridians, and emerge in the midst of landscape plantings and trampled lawns. Del Tredici observes that, from a plant?s perspective, it is not the density of human population that makes an environment urban, but the abundance of paving and disturbance. Once a landscape has become urban and the original native habitat has been destroyed, these urban plants have become the new native species.

    This lushly illustrated field guide is the first of its kind. While it covers the area bounded by Montreal, Boston, Washington, D.C. and Detroit, it is broadly applicable to temperate urban environments across North America. The book covers 222 species with descriptive information including:

    • 966 color photos
    • Scientific name and taxonomic authority
    • Synonyms, older scientific names and alternative common names
    • Botanical family, life form, place of origin, and identification features
    • Flowers and fruit
    • Germination and regeneration
    • Ecological function
    • Similar species: how to distinguish the primary species from others
    • Habitat preferences
    • Original full-color photographs showing characteristics and growth forms in typical habitats.

  2. Thank you for the post. I encounter pseudoscience all the time. Could you explain further ‘guilds’. Does it mean plants that vie for the same minerals, etc. in the soil. Does it include the needs for light and water?

  3. Short answer: light and water are often limiting resources, so plants in the same guild would compete for these more than plants in different guilds. As an aside, the definition of ecological guilds has been tweaked over time, as ecologists fine-tune their understanding of community structures.

  4. Ray, I just saw a posting about this on Garden Rant and was wondering much the same thing. I’ll try to find it (though I’m not sure it will be easy on this side of the country).

  5. When I defined “sustainable gardening” for my book, I compared it to various terms including organic gardening and permaculture. My thought on permaculture is that it contains a lot of “New Age” societal manipulation. Here’s my comparison:

    “Permaculture is often described by the accompanying subtitle, ‘Sustainable Living.’ The practice of permaculture extends beyond gardening and agriculture to more politicized arenas, such as urban planning, sociology, ethics, and reducing people’s reliance upon those industrial systems that adversely impact ecosystems and neighborhoods. Permaculture design begins with a set of ethics: first, ‘care for the Earth’; second, ‘care for the people’; and third, ‘set limits to population and consumption.’ This is an admirable but often controversial formula to push people to exchange wasteful ways for more sustainable lifestyle choices. Sustainable landscape management is one part of the permaculture movement.”

  6. Thanks for an excellent description. As a plant ecologist turned garden educator, I’m always bemused by the enthusiasm for permaculture, and the willingness to embrace what basically is not ecologically sound. I’m totally in favor of being as sustainable and ecological as I can, both in my own gardens, and in my teaching, but permaculture, as you say, is not scientifically-based, although the ideas are certainly reasonable to contemplate.

  7. Hmmm,
    so i dont know exactly why everything should be sientific. Why isnt common sense enough rational to act on? i rememer toby hemenway in his introduction to the book or the glossary where he explains the different meanings of guild for permaculture en ecologists. he uses this word because, after it being used by founder b. mollison is has become widely-used by many peopleover the world. trying to get everybody to use a new word sounds silly to me.

    further i dont think permaculture (this might be different in the states) is pretending to be scientific, it actually sometimes defies science as the way to go about everything in life.

    the books of mr. masanobu fukuoka, might shed some interesting light on the role of scientists in ecology and agriculture… the one-straw-revolution is an almost filosophical book written by a former scientist

    1. Chris’ question of why everything should be scientific perhaps points more to a problem of not knowing exactly what “science” is. The gold standard of double-blind randomised testing is one part of science. The other is refusing to hold onto cherished, long-held theories (even your own ones!) once all available evidence shows them to be wrong. In this way, Permaculture is true science. If something doesn’t work, it’s abandoned in favour of something that does. Toiling away day after day, year after year to maintain a perfect lawn with sculptured hedges, only to see the weeds come in and take over the minute you turn your back and dare to go on holidays, doesn’t strike me as being very scientific.

  8. Glad to see some criticism of permaculture. Permaculture isn’t simply ‘a science’. It also isn’t compatible with the currently industrialized research of state colleges. So it doesn’t surprise me to see this criticism beginning to flow from those institutions in response to the groundswell if interest in permaculture.

  9. I respect and understand the skepticism of scientists of the claim by some that permaculture is a wing of science. I don’t think, however, that the movement in general claims to be a science. Permaculture is highly experiemental, and in that regard is somewhat scientific in it’s methods. You experiment, observe, accept feedback, revisit, reconfigure, try again. We benefit from the data of ecologists and proceed methodically testing hypotheses in our designed systems, but only the misinformed among us would call themselves scientists. What we call ourselves is beside the point. What permaculturists are trying to do has relevance way beyond understanding the nuts and bolts of ecological systems. Ecologists can spend their lives restoring delicate native landscapes, but in the end unless we rethink and overhaul industrial civilization itself one day the inevitable bulldozers will plow down such delicate habitats for development and resource extraction. A perpetual growth economy is destined to devour everything in it’s path- the logic of the cancer cell. The point of permaculture is not to study nature as detached observer. The point is that we are nature. We are no less dependent on the well being of nature than any other species. Only in radically changing the way we produce food, procure water, house and clothe ourselves, travel, etc, can we begin to harmonize ourselves with the systems we rely on to inhabit the planet. We are in the experimental process still with permaculture. We don’t entirely know if it will work. But we’re seeing great things happen- rising water tables in lands made barren by industrial agriculture after the planting of “food forests”; the global transition town movement; thousands of people who’ve never gardened before inspired to observe patterns and systems in nature and learn from them to start providing more for themselves in a low maintenance way. It’s important to see beyond the question of whether this is science or pseudoscience and get it that this movement has the integrity and potential to save our world from ourselves. It’s about the only concept I’ve ever come across that could.

    1. Scott, I appreciate your rational philosophy and willingness to challenge the permaculture status quo. Those people who are willing to do the research and need help in learning how to do so can ask those of us who run this blog for assistance. If the research is done properly, it can be published in a scientific journal.

  10. I study, and to a degree, practice the philosophy of permaculture, having completed a Permaculture Design Course and read as much material as I can get my hands on. However, as a skeptic and someone who wants evidence, I agree with you Linda that there needs to be a new book written that is up to date and blends the design philosophy and ethics with proven scientific methods for building sustainable human systems. “Permaculture 2.0” if you will.

    Another critique of the Permaculture literature, and classes, is the use of the same references across authors and instructors to come to the same conclusions without looking further. A rather notorious example in my mind is David Theodoropoulos’s “Invasion Biology: Critique of a Pseudoscience” which on the surface looks like a well researched and clearly articulated argument against Invasion Biology, but many of the references are the author’s own unpublished personal field studies. To the uninitiated this looks very convincing but under the surface falls apart.

    The best book, in my mind, on permaculture at this point is The Earthcare Manual by Patrick Whitefield. Though not perfect, his book had the most modern bibliography I could find and he at least tries to justify his statements with research, to varying degrees of success.

    I *want* there to be double blind randomized controlled studies of permaculture design to show the methods can make a difference. If they don’t work, then how can they be adapted to fit the current science and form a functioning supported method of design?

  11. I want to express much gratitude to you Linda for starting this discussion. I took the permaculture design course in 2007-2008 and have become a bit of a sceptic since. You are absolutely correct that permaculture needs much scientific review. Many claims are made that are unsubstantiated and, upon reflection, observation and experience, I believe are untrue or misleading. These include claims about high productivity, low labour input, economic viability and others. There really is a major element of ‘cultishness’ and lack of sceptical critical thinking in the permaculture movement which will do no one any good in the long run. One of my major pet peeves about many permaculturalists is the notion that they will make a living from permaculture… by giving (not inexpensive) courses on it to others. I ask “where’s the beef”: if permaculture really is a viable economic model, then where are the people living well only from permaculture itself (and not by raking in money from true believers eager to become ‘gurus’ themselves)? My experience is that most permaculturalists, especially the most vehement ones, come to it with little actual gardening experience (I came with about 3 decades’ worth). There is definitely some value in some of the techniques and principles, but my overall conclusion is that there’s a lot of not-well-thought-out or substantiated hype, over attribution to permaculture (of gardening and/or ecological practices that did not originate there) and, yes, not just a smidgeon of pseudoscience.

  12. a more constructive question is, “are the definitions useful to the intended audience?”

    If not, how can you help improve them so that they are useful?

    Mr. Hemenway did not write Gaia’s Garden to an audience of invasion biologists! He makes very clear who his intended audience is: gardeners.

    It’s low form to claim that he is “misusing” terms. He has different definitions for them. No, they are not as rigorous, but they are also completely different in intention, substance, context and use. He’s speaking a different language.

    Most permaculturists probably aren’t scientists, they are gardeners, designers, architects, planners, etc. If scientists have issue with the serious lack of data to back the as-of-yet scientifically unfounded claims of permaculturists, then they as scientists should get up off their arses and study some of the claims! That’s what scientists are supposed to do…

    1. As I’ve mentioned – many times – on this blog, it’s not up to skeptics to disprove a hypothesis. It’s up to the proponents to provide supporting evidence. That’s the way that science works. If permaculturists continue to claim scientific foundations for their practices, then they need to meet the standards that science sets.

  13. Having read through the astute criticisms above, I wander into my urban garden. Pulling some precocious elderberry aside, I walk down a disappearing path, startling butterflies on sweet goldenrod (for tea), releasing aromas from basil, mints and other herbs as I brush by, causing a huge spider to retreat to the edge of its masterpiece strung in a patch of perennial arugula and volunteer lamb’s quarters. Passion fruits from a vine that decided to scale our plum tree bob on my head as I tread past seminole pumpkins with improbably cable-thick stalks, sprawling among sugar cane, chinquapin, apple, loquat, fig, mulberry, satsuma. Pecans hover above and behind these. Amid carpets of sweet potato, field peas, and sprawling squash pierced by asparagus, our outdoor dining room/cylindrical trellis is swallowed by luffa, kiwi, and perennial lablab and lima beans. Ducks and chickens forage freely for bugs and worms in the layers of leaves and woodchips rotting below. A raptor appears overhead and they vanish for safety among edible canna, bush cherries, and blackberries. Dusk brings choruses of amphibians who hide in edible taro and cucumbers at our small pond’s edge. I pick a cluster of grapes off the side of my house and in amazement think, “Science or pseudoscience, this is working!” I didn’t describe this to flatter myself as a gardener. I’ve only been doing this for 8 years and make tons of mistakes. Much of it developed beyond my design or management. “If you build it they will come.” Perennials, native and exotic, and annuals mostly reseeding themselves now have found almost an equilibrium as a recombinant localized ecosystem. Associated creatures find their niches as mobile members of the community. Is it low maintenance? Yes, compared to annually turning over the soil then irrigating and fertilizing to replace nutrients and water-storing soil structure you’ve caused to erode away. There’s some weeding, like slashing down locust saplings who are preparing the land for its destiny as an eastern deciduous forest. A little watering from the rain tank, some fruit moths on the peaches to contend with. Is it “highly productive?” Depends on what you’re trying to produce.I don’t have crates of identical tomatoes to sell at market, though I have lots of this and that to trade with neighbors. We can’t remotely produce all our food from our tenth acre, but often much of the food on our plates came from just outside the door. It’s very productive in terms of biomass. “Productive” American subsidized mega farms of corn lose 3-5 bushels of topsoil for every bushel of corn produced. Tree-based perennial systems store energy as wood, plant stalks, and layers of leaves that become humus. This hosts billions of decomposers, charges springs with stored rainfall, and kickstarts foodwebs. If, like Wendell Berry, we “call that profit”, permaculture’s potential for this kind of profitability and productivity may be trumped only by wild nature. Is it financially profitable? No, it’s money-saving, and that’s the point for many of us. In our society freedom is only possible for those with enough money to do whatever they want and for those who need little money. Everyone else is more or less in a snare. In my factory worker days I would have called it a noose. Our economic system runs on perceived scarcity and competition. Permaculture explores what happens if we embrace abundance and cooperation instead. I’m working to need less money all the time. It’s allowed me to be present for my kids’ childhoods.
    Permaculture often attracts people with little horticultural know-how but who get it about the ripples created by taking more responsibility for the streams of food, energy and waste a household consumes. Localized resillience, communities of many households growing food, catching rainwater, generating electricity, biking to work, etc, begins to transform global dynamics. All wars at their core are resource wars. They defend elite investments and protect access to raw materials so that goods can be sold cheaply to helpless consumers. Our economic system mandates that people be severed from the means of providing entirely for themselves, and world history abounds with examples. Permaculture is a revolution that starts in your backyard but has global dimensions of social and environmental justice. It doesn’t have all the answers, and yes, it needs rigorous scientific scrutiny. Welcome scientists! We need your help in the most important work of the 21st century- redesigning human existence on Earth so that there will be a future worth living in. 40 million acres of America are growing lawns no one can eat. We’ve got a lot of work to do- join us!

  14. “We’ve had some good, vigorous discussion about permaculture, specifically around the book Gaia’s Garden.”

    Where do I find the beginning of this series?

    1. Leigh, they are on May 12, May 5, and April 28, all 2010. (There is a search box right under the “Garden Professors” banner, and you can search for key words there.)

  15. I realize I am late to this conversation, but I very much appreciate the discussion. I am a trained scientist and also a permaculturist. I am all too aware on the lack of science in permaculture and I think it’s a big problem. I do think much that is in permaculture would stand up to scientific investigations (although a lot of the permaculture dogma that is passed down from teachers to students would not), but unfortunately due the complex non-homogeneous nature of permaculture systems, it’s not very easy to come up with a good methodology for testing them on various aspects. It would be my dream to carry out some proper scientific studies on permaculture systems. Does anyone have any ideas on a framework and methodology for a good permaculture experiment?

    1. Hi Danielle,
      I just started my PhD this year in Plant and Environmental Science. I too have been saddened by the lack of science in permaculture circles. If you’d like to chat more about experimental design, feel free to drop a line. I’d love to hear from you!

      1. Hi Holly. I know this is an old comment, but it would be lovely to connect with others interested in the scientific aspects of PC.

  16. Adam, there’s never a too late for this forum! In answer to your question, I don’t think there’s one definitive experiment one could do. There are ways to test certain aspects of permaculture (companion planting, for instance). Past that, we could apply ecological theory to home gardens and landscapes – the theory being based on a collection of testable hypotheses in plant and soil sciences. In fact, much of what permaculture offers is based in ecological science. The problem is that the science has been mysticized to broaden its appeal. This is unfortunate IMO, because the science, when explained coherently, is infinitely more fascinating than the myths surrounding it.

  17. There have been lots of people who have been called scientists through out history who didn’t perform double blind studies that very many living people who are referred to as scientists today perform. It seems to me that an accurate what to define science is to say it is about doing experiments rather than just thinking about things even if this is called a ‘thought experiment’. It is possible for one experiment to be better or more rigorous or more beneficial than another experiment. An experiment can even be worthless because of how poorly it was done. This doesn’t mean what was done wasn’t science, it just means that it was poorly done science.

  18. Hello,

    I wonder if anybody with gardening expertise had a look into the two original “permaculture bibles” “The Designers Manual” and “Earth Care Manual”. I would also be interested in what experts think about the biointensive farming method (devised by John Jeavons; in the Grow More Vegetables book you find an awful lot of numbers – I would be interested, what you experts think about it). An to finish of and you still have time, I also would like to know your opinions on the System of Rice intensification and its adaption on other crops (e.g. wheat – I am currently conducting two little private experiments (20sqm), where at the moment I cannot say much about the results).
    I would be also interested to be pointed to adequat science-based gardening literature.

    Thanks for your time!
    Best regards
    Wolf F.

  19. There is currently a PC field trial being conducted in France, the first results should start being published later this year. From what I have heard, early indications are that this system under investigation is more productive than neighbouring conventional farms. It would be really good to have some credible data on this at last!

  20. First to look at the authors criticisms of terms/definitions.

    I understand that those in the field of biology or any field for that matter do not like to see other people use their words out of the context they are used to or to mean something different. However as many have pointed out in the discussion Toby’s book was not for or even remotely aimed at (for better or worse) at those in this field, but those folks who have 1/4, 1, 5 acres and a house. After having been in the military it grinds a bit to have people describe certain types of weapons as “assault” or anything being “tactical” because it has camo on it. I get that being in a certain field to have terms used other than they are intended bothers those “in the know”.

    However while some earlier posts had legitimate criticisms this sounds more like splitting hairs and complaints than real legitimate criticisms. The bibliography is describing how this word is to be understand in the context of the texts.

    When Toby is saying that between the black walnut tree and your strawberries/chives you should have a “Buffer plant”, the reader may say “huh whats that mean” they go to the bibliography and ready that in that case its a plant that will not adversely affect the strawberry/chive guild but also not be affected by the alleopathic qualities of the walnut. They say to themselves “Ok” and now understands what he meant. If someday the .0001% who end up becoming a ecologist/biologiest after reading this encounter the word in their academic path they will learn what that world means when they say buffer. How many people who read a gardening book, permaculture or conventional will ever need to know what a ecologists considers a buffer plant to “really” mean. they know what the author intended and will now go out and do it and will probably never run into a text that is describing the plants near a wetland.

    Now Permaculture is more of a philosophy and less a science however as has been described it is factually based. If you read in a permaculture forum of book that you should be able to grow Pawpaw in your zone and should have it and you try and it doesnt work, then you probably try somewhere else on your property and if it doesnt work then you move on and try something else. Thats what i really like about it, you use what works, if it worked for someone else but not you then that is how it is. It is not subject to conventional scientific method and trials/testing because frankly we that practice it dont have the time or funding to do it and theres no grants from big ag to prove or dissprove a method counter to their bottom line. The fact also is the revolving door at the Federal and some extent state level between large agricultural companies and those that dole out this cash is also a part of the problem.


    That may be so. However we (i should say I) dont really care all that much about providing a scientific study to be poured over. As mentioned i dont have the time and/or money to do so, however if you walk into my property you will find many of the methods described in the book in action and providing more food than you can eat. 15 different types of berries in brambles across the edges, hardy kiwi, pawpaw, apple, apricot, plum and cherry vegetable and herb gardens brimming with growth all healthy and living in concert with the microbes in the soil and the insects crawling above. it may not be scientifically proven, but it is proven in action. I am not anti-science or a luddite of any sort, i use what works, if science proves a concept and it works in my food forest, i use it, if a permaculturist publishes an article calling sheet mulching “Flibbery flubbery bubble gut newtonian physics” then thats what ill use. i dont split hairs over a name, I focus on the underlying supposition. If what is described might work and i try it and it works, it works. science is necessary and i welcome it in whatever form may be used to prove or dissprove theories in permactulture practice and design. however i dont want to wait years or decades for the science to be decided when i can figure out this seasons or over a couple if it works for me. In the end permaculture seeks at every means and ever end to mimic nature, the means may not result in the end we want, but if that end mimics nature then that is proof enough for me to use it, nature is fact, science merely describes the mechanisms in which it works.

    1. If permaculturists wish to have their methods considered to be a philosophical body of knowledge, that’s fine. However, this book and many others take language and descriptions that have been developed through scientific inquiry and use it out of context. Language derived from the field of ecology needs to be used accurately and the practices derived from ecological studies need to be science-based for permaculturists to claim their methods are simply applied ecology. As it currently exists, permaculture is a tangle of philosophy, science, and pseudoscience. That makes it very difficult to study and discuss holistically.

  21. Anonymous reports above that they ‘can’t remotely produce all our own food on our one tenth of an acre’. Why not? I rent 430 sq m. Almost 1/10th of an acre of loamy sand without synthetic inputs or cash investment beyond seed and sundries. I grow more fruit and veg than we can eat, including more than 100 types of plant in more than 160 varieties, in a 12 month cropping cycle. This does not cover our use of flour for bread, dairy or meat, spices etc… Nevertheless, while we do not grow all out own food, it is scarely a remote goal. If we you want a stylistic reference we’re somewhere in the region of ‘intensive / cottage gardening’. The question arises therefore how to gauge our relative impacts on our environments, the balance of higher natural biodiversity against a smaller food resource footprint. How do we assess that balance without scientific statistical analysis, I dunno, but I’m not persuaded that permaculture has the edge.

  22. For me, science is about the use of logic and evidence to gain knowledge and understanding about the world around us–also within or bodies and minds–and to guide us in the management of our bodies and our surroundings. Science helps us in our decision-making.

    By these standards, I see permaculture as scientific. And I love to learn about and apply “strict science” studies and results.

    What is the problem here? I don’t see it.

    Surely we can and must march together to protect and regenerate the biosphere that birthed and sustains–for now anyway. If not, then we and all are surely doomed.

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