Permaculture – the discussion continues

We’ve started a robust discussion on the topic of permaculture, especially as applied to home gardens.  Let’s continue looking at some of the advice provided in Gaia’s Garden targeted towards home gardeners.

The book contains several lists of plants suggested for specific functions.  For brevity’s sake, I’ll just mention two:

“Host plants for Beneficial Insects” (pp. 157-159)
This list is prefaced in the text with “many of these florae are very attractive and can (and should!) be included even in the most formal garden bed.”  With this strong endorsement, the author then presents an unsourced list of plants, several of which are identified as noxious weeds in many states in the country.  They include Washington noxious weeds false indigo (Amorpha fruticosa), fennel (Foeniculum vulgare), Queen Anne’s lace (Daucus carota), toadflax (Linaria vulgaris), cinquefoil (Potentilla recta), sulfur groundsel (Senecio vulgare), and tansy (Tanacetum vulgare).

“Dynamic Nutrient Accumulators” (pp. 131-134)
We are told “certain species draw specific nutrients from deep in the soil and concentrate them in their leaves” and given an extensive table of these plants and exactly which nutrients they accumulate. The references for this table are not scientific, and in at least two cases are mystical in nature (Cocannouer’s Weeds: Guardians of the Soil and Pfeiffer’s Weeds and What They Tell).  As in the previous table, many of these plants are designated noxious weeds in Washington or other states and include nodding thistle (Carduus nutans), Canada thistle (Cirsium arvense), fennel (Foeniculum vulgare), toadflax (Linaria vulgaris), creeping thistle (Sonchus arvense), and tansy (Tanacetum vulgare).

As readers of this blog know by now, we GPs are not “plant purists.”  But it is highly irresponsible to encourage people to plant listed noxious weeds in their gardens.  Even the author seems to understand this, and states (on page 15) that “it is foolish to deliberately introduce a species known to be locally opportunistic.”  It’s mystifying, then, that he does exactly that in these two tables.

The inclusion of the table of “dynamic nutrient accumulators” demonstrates that this book tends to wander far afield of the philosophical roots of permaculture.  It is an excellent example of pseudoscience, as it creates a scientific-sounding phrase (“dynamic nutrient accumulator”) and misleads non-experts into believing a scientific claim (nutrient accumulation of specific minerals) without providing actual supporting data.

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Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and a Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - "The Garden Professors" Facebook group - Books:

9 thoughts on “Permaculture – the discussion continues”

  1. I 100% agree regarding objections due to presenting pseudo-science as science. As a simple hobbyist, I grow weary of claims that aren’t backed up by rigorous scientific evidence, but I lack the time and library resources to personally follow up research myself. That’s why I follow this blog.

    But I’m concerned by your attitude towards the treatment of invasives. If the author said people should check their local invasives listing (I check my region on the usda website before I add anything in my garden), they’ve done their due diligence. Probably it would be better if they had an appendix in the back with some resources for people to check by various regions, but beyond that, what else can they do?

    I’m a little troubled by the expectation that any book on gardening somehow
    tell you which plants it recommends are invasive for the reader. All invasive plants are native somewhere. There are plants that are invasive in the US west coast that are native to the US east coast, so is a book supposed to pretend some northeastern plants that might do well in northeastern gardens aren’t options? Furthermore, the United States is not the center of the universe. An English language book can aim for distribution pretty much anywhere that used to be part of the British Empire: Great Britain, US, Canada, Australia, New Zealand, South Africa, etc. It would break up the narrative to try to cover every plant that was invasive anywhere. Maybe they could put a little star by any plant that was invasive anywhere in the world, but that adds seriously to the research load in writing the book. The author could research their local list and just write the book with respect to it, but that wouldn’t encourage people from other regions to think about the issue at all, and plants that are innocuous in the author’s region might be invasive elsewhere. Plus, science progresses and these lists will change, so telling people to find their local listings seems better. Send people to check their local lists often enough and they’ll have real knowledge to take when they read other books that don’t broach the subject at all.

  2. @ nobody, I’ve deliberately not mentioned the established weeds that these lists also contain, as I agree with some of what you say regarding invasives. I’ve limited discussion to regulated noxious weeds, which are so listed because they aren’t yet widely established and thus their invasion might be slowed down or prevented at local levels. If someone is going to promote invasive species, they need to be aware of the legal ramifications of doing so. There is an easily accessible data base at which has both federal and state noxious weed lists. It would have been more responsible to include this type of information as a courtesy to gardeners, who unwittingly could violate state laws. Did you know there are monetary penalities for not managing noxious weeds? You can see Washington state’s laws here: Like it or not, this is the way things are. Gardeners need to be aware of reality.

  3. I’m aware of the penalty for noxious weeds (although one doesn’t exist in my state). And the author by your accounts raises the issue of invasives and says growing them is bad. If the author hasn’t made it clear that you should look up everything you plant to make sure its not invasive, that’s a serious problem. The thing that bothers me primarily is the US-Centric attitude. The notion that because a book is in English, it’s ours and it should cater to Americans. And that’s not the reality. I’m not denying that. What bothers me is the fact that you seem to be pissed off that they haven’t singled out plants that are invasive for you with flashing red lights. You haven’t even considered the notion that some of the book’s target audience could be in another country where those are natives. For example: I’m in the US and I’m trying to establish prickly pear: good stuff, edible, native–FOR ME. But it’s heinously invasive in Australia, New Zealand, and South Africa–all English-speaking countries that might want to read this book. And, I’m guessing this book mentions prickly pears favourably, and this likely hasn’t bothered you one bit. Rather than advocating that the author take a stronger position in teaching what invasives are, how bad they can be, and how people everywhere can find out what’s invasive for them (which I think is a completely legitimate and appropriate thing to attack them for if their section about invasives wasn’t strong enough), you’re attacking the author for advocating plants that are invasive for you while pretending that your natives aren’t invasive elsewhere.

  4. For brevity’s sake, I’ve not included all the international noxious weed lists (which are easily found on the web). Of course many of our natives are invasive elsewhere – that’s why it’s a global problem. (And where did you get the idea that I “pretend” my natives aren’t invasive elsewhere?) So again, for brevity’s sake, I’ve only pointed out the weeds that are noxious in my state. I think that gets the message across. And no, the author does not suggest looking up plants to find out if they’re locally invasive, nor does he say growing them is bad. That’s why I included the websites I did in my earlier comment. I would expect the author to be ethically responsible and include these websites in the book along with the lists of recommended weeds.

  5. I appreciate reading your comments on the permaculture movement, which has a very strong following here in Portland.

    I’ve tried to read Gaia’s Garden, but was so put off by the lack of scientific rigor, than I couldn’t justify investing time in it, so I’m really glad to see the critiques on this blog. I also enjoy reading the comments that your posts generate.

    If I had to pick one permaculture tenet that I really don’t agree with, it would be the idea that weeds in their role as dynamic nutrient accumulators are of greater benefit than conventional agriculture’s view of them as competitors for nutrients, and thus should be left in place. While the conventional agriculture practice of weed suppression has much research supporting it, I would love to see research that supports the permaculture view.

    Keep up the good work. I look forward to more posts regarding permaculture.

  6. These health benefits seem to be very good reason for increasing
    one’s consumption of kale. Water – The collection of water forms
    possibly the most important part of permaculture.

    The wildlife they are exposed to is often mediated by technology or educational curriculum that just doesn’t offer the allure of a virtual world.

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