Book Review: Creating a Forest Garden
Working with nature to grow edible Crops
by Martin Crawford
Green Books Hardback 384 pp
Forward by Rob Hopkins
Martin Crawford, Director of the Agroforestry Research Trust in Devon, UK, has produced a beautiful and practical book which seems sure to become the definitive text for cool temperate forest gardens.
As part of his work at the ART Martin is already the author of many encyclopedic manuals covering dozens of topics and thousands of plants, and has been producing the essential Agroforestry News since he began his forest garden in the Dartington estate 15 years ago.
Above: Martin engulfed by bamboo with Italian Alder growing behind him at his garden at the ART
Creating a Forest Garden is eminently practical and down-to-earth, packed with information and good advice, and illustrated throughout with really gorgeous colour photos, including many full-page ones making it of interest to the general lover of plants and gardens as well as the serious forest garden designer. As such it succeeds in bringing together the technical issues of forest garden design, comprehensive details on edible and useful plants as well as introducing the concept to the non-specialist.
The concept of edible “food forests” -combining tree crops such as top fruit and nuts with various understory layers such as small and large shrubs, perennial vegetables, ground-covers, herbs and climbers- expresses many of the principles of permaculture: multiple function; stacking different layers; diversity and use of biological functions such as nitrogen fixing plants.
The book is clearly laid out into three sections:
Part 1 How Forest gardens Work
This section introduces the reader to the concept of forest gardens and how they evolved in British climates from the work of Robert Hart;
There follows a survey of forest garden features and products;
a fascinating look at the effects of climate change on the UK climate and the relevance of forest gardens to landscapes resilient to these changes;
and a brief discussion on the “native-exotic” debate- Martin points out that many definitions of what constitutes a “native plant” are in fact arbitrary:
…plants introduced by other animals to a new area are “allowed” as native but those introduced by humans (deliberately or not) are not. This is an example of the all-too-common attitude of the last few centuries, of humans being separated off from the natural world as though they are not a part of it. Just look where that has lead us!
This is an important issue to forest gardeners – as Martin points out, the range of “native” wild edibles is quite small in this part of the world; productive forest gardens here will need to introduce many plants, but it should be remembered that few of our food corps- much less ornamental shrubs- are actually “native” anyway.
This section ends with a detailed look at fertility in forest gardens. Martin shows how to make an assessment of the nutrient demands of your plants and average this out over the area you have, and then how to calculate how to meet this demand from nitrogen fixing plants and mineral accumulators like comfrey.
This key idea in forest gardens of achieving a high degree of self-maintenance is one of the great strengths of Martin’s approach. Unlike conventional annual veg growing, which tends to rely on inputs of manures for fertility, a forest garden would ideally cycle its own nutrients as far as possible and limit any extra inputs.
Part 2 Designing Your Forest Garden explains the other major aspect of the self-maintaining nature of edible forest gardens- they should have perennial or evergreen groundcovers to minimize weeds.
The key to this is how to establish useful ground covers that you want in the first place. In the book Martin shows how to first eliminate the existing vegetation with plastic or cardboard mulches, which should be down for a year before removing and then planting the area with suitable beneficial ground cover plants. In my experience this is the aspect of forest gardening that is most commonly neglected or poorly implemented- people’s initial interest tends to draw them to the trees and shrubs, but in many ways it seems to me that it is the perennial vegetable and ground cover layers that really define it as such- rather than an orchard with grass that needs mowing, and this takes careful preparation and selection of species.
The chapter on growing your own plants will be essential to most gardeners- the number of ground cover plants needed to fill a space quickly and keep those weeds down can be considerable and beyond most people’s budget. Martin takes you through the main propagation techniques for a range of plants including grafting trees and shrubs.
Chapters 9 and 10 take the reader from first design steps -starting with the selection of a suitable site if one is the market for buying land- and the important aspect of wind-break design.
Then follows a series of chapters for designing each in turn the canopy layer; the shrub layer; the herbaceous perennial and ground-cover layers; and annuals, biennials and climbers, with a chapter for each with comprehensive plant lists that make for hours of happy browsing and nearly justify the book purchase on their own
Part 3 Extra Design Elements and Maintenance covers the landscape features of paths and clearings and how design them into your forest garden for maximum light.
This followed by a chapter on one of the most fascinating potential yields that an be added into a forest garden- edible fungi and how to grow them on logs or sawdust;
-harvesting and preserving- tips on what to do once you have an abundance of yields;
and finally chapters on maintenance, including weeding (which is essential but should take minimal time in a forest garden) and pest control; and ongoing tasks.
Four useful glossary’s are found at the back of the book: Propagation tables; trees and shrubs for hedging and fencing; plants to attract beneficial insects; and edible crops by month of use.
Resources- useful organizations, suppliers and publications- complete the book
There is very little I could suggest to improve this comprehensive book. I would have liked to see a couple of references to research in places- for example in the first chapter he states “there is plenty of evidence that crops from perennial plants tend to be more nutritious than similar plants from annual plants”- it would be interesting to have some references to follow up.
My visit to Martin’s 2-acre forest garden in 2008 was an inspiration, reinvigorating my interest in the potential of the concept, and showing how multiple yields can be obtained efficiently with relatively little maintenance required.
While there is still little data to demonstrate to what extent forest gardens can really feed people in this part of the world- Martin does not claim they can or should completely replace annual vegetable gardens or conventional farming- this wonderful book is another demonstration of how the edible forest garden concept can successfully integrate productive food gardens with diverse habitats, and providing many other ecological and aesthetic qualities. It is sure to inspire many more new forest gardens and gardeners over the coming years.
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Thanks for a great review of what looks like an extremely useful and important book. I expect to buy and read it.
I was just a bit annoyed that you ignored Dave Jacke’s 1000-page “Edible Forest Gardens”. Although Crawford’s book may well be the definitive introduction to forest gardening, I’d still say that Jacke’s book is the definitve “text”.
Note to North American readers: Won’t be published here until Sept. You can pre-order it through Amazon.
Hi Christine well I havn’t deliberately “ignored” Jacke’s book, but it’s true I never got around to reviewing it- maybe i can correct that sometime! It is of course fabulous, and you are probably right as far as a text-book goes… I think Crawford’s book is aimed more specifically at British climates though which is why I made that comment.
Hi Graham,
Thanks for the review. I’m hoping to start planting a few trees at my place and wondering about the best way to plan it. Hopefully Crawford’s book will come in handy.
With regard to the native-exotic debate: The point Crawford makes about native edible plants is a valid one and if we were to eliminate all non-native species we would quickly find ourselves with very little to eat. Very few species, relative to the number that are introduced, become invasive in a new ecosystem. However, the ecological literature clearly demonstrates the threat that non-native invasive species poses to biodiversity. On a global scale they represent the second most significant cause of biodiversity loss, next to habitat destruction (Keane & Crawley, 2002).
The phenomenon of introduced species is not a modern one. In fact, the disturbance of ecosystems by the arrival of new exotic species has been occurring continuously throughout Earth’s history. For example, the Isthmus of Panama, which forms a land bridge between North and South America, was submerged under water on several occasions in the past (Elton, 1958). During these periods, the biota of the two continents evolved in isolation from one another. However, once the land bridge was formed, mass migrations of animals and plants took place across it and they interacted with one another. It is also known that organisms are sometimes transported long distances on sea rafts of vegetation to new locations. A monkey was seen on floating timber off the coast of Java in 1883, for example (Elton, 1958). As a result, many argue that the problem of introduced species is not a problem as such but is simply a continuation of a natural process that has been happening for millions of years (Wagner, 1993). There is no denying, however, that global commerce, travel and trade is accelerating this interchange of species between different habitats and ecosystems (di Castri, 1989; Wagner, 1993). Not only are we accelerating the process but we have also changed the type of organisms that find their way into new habitats. For example, the Zebra Mussel, Dreissena polymorpha, a freshwater species native to the Caspian Sea in Asia, was accidentally introduced to the Great Lakes of North America more than likely from the ballast water of a ship (Johnson & Carlton, 1996). This invasive species has caused extensive damage to many freshwater systems throughout the United States. Without the intervention of man, it seems extremely unlikely that the Zebra Mussel would ever have found its way to the Great Lakes through natural dispersion methods.
The example of the Zebra Mussel is but one and there are many more where plant species are problem. The Zebra Mussel is not beginning to impact on freshwater systems in Ireland. As you say, it is an important issue for gardeners but it is a topic that I have never seen discussed in any great depth in permaculture circles. “Use and Value Diversity” is one of Holmgrens design principles. Introducing all kinds of different plants to be utilised in our gardens is indeed using biodiversity but when it comes to valuing diversity, perhaps we should be bit more cautious when choosing which plants and other species we introduce.
References:
Elton, C.S. 1958. The Ecology of Invasions by Animals and Plants, Chapman and Hall, London.
di Castri, F. 1989. History of Biological Invasions with Special Emphasis on the Old World. In: Biological Invasions: a Global Perspective (J.A. Drake, H.A. Mooney, F, di Castri, R.H. Groves, F.J. Kruger, M. Rejmanek & M. Williamson, eds). John Wiley and Sons, New York.
Johnson, L.E. & J.T. Carlton. 1996. Post-Establishment Spread in Large-Scale Invasions: Dispersal Mechanisms of the Zebra Mussel Dreissena Polymorpha. Ecology, Vol. 77, No. 6, pp 1686-1690.
Keane, M.R & M.J. Crawley. 2002. Exotic Plant invasions and the Enemy Release Hypothesis. Trends in Ecology & Evolution, Vol. 17, Issue 4. pp 164-170.
Wagner, W.H. 1993. Problem with Biotic Invasives: A Biologist’s Viewpoint. In: McKnight B.N., editor. Biological Pollution: The Control and Impact of Invasive Exotic Species, Indiana Academy of Science.
Regards, Eoin
“The Zebra Mussel is not beginning to impact on freshwater systems in Ireland.”
Should read - The Zebra Mussel is now beginning to impact on freshwater systems in Ireland.
Hi Eoin Good points. Actually holmgren has written extensively on this topic- see for example his review of Theodoropoulos “Invasion Biology- Critique of a Pseudoscience”. (2003):
http://holmgren.eatthesuburbs.org/DLFiles/PDFs/InvasionBiolReview.pdf
Holmgren’s main concern is the arbitrary and ideological way that he sees environmental policy being implemented- “natives good, exotics bad”. In fact a whole load of other issues also play a role: many invasive s are so because they fill a niche left after wholesale ecological destruction. Holmgren gives the example of the Southern Alps in New Zealand- almost completely denuded by human activity, now being colonised by “exotic” Douglas Fir. The response? The authorities fly helicopters over them and spray this invasive weed.
What is needed is a theory of what makes a plant likely to be “invasive” so we might know what is safe to plant and what might not be. This may be obvious in most cases.
Martin Crawford makes the point that species will be migrating northwards with climate change, and our concept of what is native will also change with this.
There is also concern that loss of diversity of our food crops (hardly any of which are “native”) is a much bigger problem than loss of wild diversity.
Are there any examples of invasive species that have become problems as a result of forest gardeners or permaculturalists?
Holmgren concludes: “I believe that the real reason people prefer to grow native plants is that it requires less work and skill than growing your own food and that food remains so cheap… For those of us committed to household environmental responsibility, an apple is a better symbol than a gum nut.”
http://permacultureprinciples.com/downloads/23_weeds_or_wild_nature.pdf
I’m just catching up and now reading the copy of this that I was given for Christmas. Inspiring stuff – our newly planted ‘orchard’ is being developed into a forest garden now – Italian alders being planted on the north side, sheet mulch working its way across the site over then next 8 years and the creeping rubus ground cover I received from you is in a propagating bed where I’ll enjoy growing my own ground cover ready for planting out.
All very exciting and looking forward to acquiring more interesting plants. Thanks Marting for a great book and thanks Graham for the review and having an interesting selection of plants growing for me to look at!
Thanks Tom great to hear you are inspired in your Forest Garden and looking forward to seeing how it develops this spring! As you know we have a small nursery of FG plants in Derryduff- something i have held off from blogging about until we have more stock, but will do in a month or so. I currently have the first seeds up this year- Turkish Rocket seedlings, which are 2nd generation seedlings from the seeds given me by Ruth so will definitely get a couple of them to you at some point, it’s a really good perennial edible!
Just got hold of the book and wish it was around 20 years ago when I started a small wood with fruit trees. My biggest mistakes were misjudging the pace at which alders and ashes grow. There is so much info in here, this book is a priceless tool for all scale of land owners or even back gardeners.