An edible forest garden

Back in March, Susan and I did a weekend course in Melbourne with US edible forest garden expert Dave Jacke. A fun, informative weekend it was too: Dave's knowledge of all things edible and forest-dwelling is remarkable. His two-volume work Edible Forest Gardens must surely be the most detailed, informative book on the subject yet written.

But what is an edible forest garden?

An edible forest garden is an example of ecosystem mimicry. Observing a complex, self-sustaining forest ecosystem, understanding its key elements, interrelationships and processes and attempting to replicate them using plants which are human food crops.

At its most basic, a forest ecosystem might comprise:

• canopy layer – tall trees that need full sun
• understorey layer – smaller, shade-tolerant trees and shrubs
• herb layer – herbaceous perennials
• groundcover layer

The idea of edible forest gardening is to fill all of these niches with plants that are edible or otherwise useful to gardeners, and to do it in such a way that competition is kept to a minimum and mutually beneficial (symbiotic) relationships are maximised.

That's a very rudimentary attempt to describe the theory; now for the practice!

A year ago Jill and Mike removed four cypress trees from their garden, leaving a grass-covered space about 20 x 8 metres. That much real estate right next to The Patch was not something I could ignore, and so I came up with various ideas to fill it, including a large polytunnel and various animal husbandry schemes more suited to a 10-hectare farmlet, before hitting on the idea of … you guessed it: an Edible Forest Garden. Henceforth known as the EFG.

Jill and Mike have been good enough to indulge my new passion, and we're starting on the EFG this winter. Here's a plan showing what the EFG should look like after about 8–10 years:

Click image for a larger version

The coloured circles represent the trees and shrubs. Informal bark paths provide access for harvesting (and wandering around) and also break up the area into patches, each of which will be dominated by one or more combinations of herbs and groundcovers.

The choice of trees and shrubs was determined to some extent by what's already in Jill's and Mike's garden: they have a wide variety of fruit trees, and there seemed little point in planting more of the same. Carob is a stately, pyramid-shaped evergreen tree from the Mediterranean area and will increasingly dominate the site visually. The design mimics an open woodland rather than a closed-canopy forest, with the tree and shrub layers covering less than 50% of the area.

When selecting the species I also attempted to bring together plant communities that would work well together and to this end I compiled a table with the key characteristics of the species I was looking at.

It will be interesting to see how far the reality of this Edible Forest Garden comes to resemble the plan!

Click image for a larger version

Edges, boundaries and paths

Cultivating the Patch is throwing up interesting questions about edges, boundaries and paths. It's a rectangle of land with minimal boundaries: a large-mesh wire fence on the north and east separating it from the neighbours' properties; a 2 metre wooden fence on the south separating it from the school oval and no boundary on the west other than Jill's and Mike's vineyard.

On the minus side, that means that there's little to block the passage of wind, rabbits and the occasional errant dog. On the plus side, there are none of the issues with shade that we have to deal with in our home garden, caused by mature trees in our and our neighbours' yards, and of course our 2-storey house. The Patch was really a horticultural blank slate.

The Patch - June 2011

Faced with a nice big block of land to grow stuff on, my tendency (and I suspect I'm not alone in this) is to think of growing space, not access, and to begrudge any land dedicated to paths and barriers.

But paths and barriers are necessary. Foot and wheelbarrow traffic compacts soil, so you don't want to walk on land you're going to grow plants in. Aggressive running grasses and other tough running weeds (we're 'blessed' with kikuyu and blanket/carpet weed) would quickly overrun the cultivated land without well-defined borders that can be 'patrolled' for incursions.

I've tried to build some Permaculture principles into how I tackle the issue of barriers – the Patch is defined to the east and west by borders of deep-rooted, perennial plants – primarily comfrey and lucerne, which resist the encroachment of running weeds, provide useful nutrients and mulch to the garden and require little maintenance or irrigation.

To the north, a wattle border will eventually be about 2 metres high and diversified with sheokes, blueberries, etc. to provide shelter from hot northerlies, mulch and enrichment for the garden and some fruit for us.

I'm happy with how those solutions are evolving, but within the garden I feel the need for permanent paths, borders and subdivisions, and I'm not entirely happy with what I've done so far in that regard. One of the issues is the tension between the Permaculture approach I've recently learned – which values edge, diversity and curvilinear forms – and the traditional European organic gardener's approach, which wants straight lines and rectangular beds. There are advantages to both approaches and I haven't yet found a balance which works for us.

The two weeks I spent at Milkwood Permaculture in NSW brought home to me that there is scope for both approaches within an enterprise which is inspired by Permaculture principles. On the one hand they have a nascent forest garden which in years to come will probably be intensely productive with little ongoing maintenance; on the other hand most of their food in these early years is produced in a very traditional looking, labour-intensive organic market garden.

Food for thought

One of the things I took away from my Permaculture Design Certificate was a long list of books I wanted to read.

Milkwood Farm, where I did my PDC, has an extensive library in the converted woolshed that is its classroom, common room, dining room and well, room for all occasions. But somehow during two weeks of intensive learning and discussion I never found time to settle down and read any of the books properly. There were always fascinating conversations to take part in or just listen to around the campfire, or thoughts to digest from the day's presentations, group tasks and workshops.

So in the last five months I've been working my way through that list, with some additions I came across along the way. Here are some of the books, grouped thematically:

Permaculture

Introduction to Permaculture, Bill Mollison with Reny Mia Slay, Tagari Publications, 1991
This is a readable introduction to permaculture by its co-founder Bill Mollison, covering the main principles and plenty of practical examples. A great place to start.

Permaculture: A Designers' Manual, Bill Mollison, Tagari Publications, 1988
This permaculture classic is the curriculum for the Permaculture Design Certificate. It's nearly 600 pages of densely packed information. Not a light read in any sense, but a must-read if you want to get serious about permaculture.

Permaculture: Principles & Pathways Beyond Sustainability, David Holmgren, Holmgren Design Services, 2002
A wide-ranging exploration of the 12 permaculture principles by co-founder David Holmgren. I found this book thought-provoking and highly enjoyable. More theoretical than the Designer's Manual - you won't find any plans for herb spirals in here. More like plans for a new civilisation.

There are several books offering detailed explanations of how to apply permaculture techniques in your backyard or on your farm, but I haven't read any of them. I'm not really interested in 'how to' books at this stage.

Soil food web

One of the key thoughts I took away from the PDC was that soil isn't just brown crumbly stuff. I've written on this in my previous post. These books are helping me to get to grips with the complex answers to the simple question 'What is soil?'

Teaming with Microbes: The Organic Gardener's Guide to the Soil Food Web, Jeff Lowenfels & Wayne Lewis, Timber Press, revised ed. 2010
This book completely revolutionised my understanding of soil and what we gardeners should be doing in the garden. Please read it.

Mycelium Running: How Mushrooms Can Help Save the World, Paul Stamets, Ten Speed Press, 2005
What are the biggest and oldest organisms on our planet? What is the key component of a forest ecosystem, connecting the others in a web of life and death? Trees, right? Wrong. Fungi.
This is a beautifully illustrated, engaging and thought-provoking book. I got a little uneasy when, about five pages in, the author informed me that fungal webs are sentient. Stick with it: this guy knows his mushrooms.

Dirt: The Erosion of Civilizations, David R. Montgomery, University of California Press, 2007
The fascinating and horrifying story of what we have been doing to our topsoil ever since Neolithic humans invented the plough. Have you ever wondered how civilisation grew up in the rocky and barren soils of Greece and Turkey? Why the Roman Empire came to an end? Why there is chronic famine in Africa? Have you ever wondered what goes into our agricultural soils? This book provides some answers.

Food

This evening I'm going to hear US writer Michael Pollan speak at The Wheeler Centre in Melbourne. Pollan is a wonderful combination of raconteur, journalist and food theorist. I've only read two of his books so far but am looking forward to reading the rest.

The Omnivore's Dilemma: A Natural History of Four Meals, Michael Pollan, Penguin, 2006
Pollan uses the preparation and consumption of four meals to show exactly where our food comes from. I'm just never going to look at maize the same way ever again. Hell, I'm never going to look at food the same way again.

The Botany of Desire: A Plant's Eye View of the World, Michael Pollan, Random House, 2001
Based on the apparently whimsical premise that plants have cultivated us as much as we have cultivated plants. This lovely book is actually a profound essay on co-evolution of species and a provocative commentary on agriculture and horticulture. Loved it.

Bees

Given that 70 of the world's most important 100 crops are pollinated by bees, and every third forkful we put in our mouths is the product of pollination by bees, bees are pretty important to humans. As gardeners, we love them. However, I didn't know much about them until I did a couple of beekeeping courses and read these books.

Honeybee Democracy, Thomas D. Seeley, Princeton University Press, 2010
This book gives the reader a fascinating insight into the life of the hive, written by one of the world's greatest authorities on bees.

Beekeeping for All, Abbé Warré, translated by Patricia and David Heaf, Northern Bee Books, 2007 (also available online as a free pdf)
This little book explains in detail a beautifully logical and simple system of beekeeping, developed by a French master beekeeper in the 1950s after a lifetime of experiment.
This is the system which Susan and I are going to use in our hives. Having done natural beekeeping courses in Sydney and Melbourne, I'm convinced that the Warré system is far more suitable for hobby beekeepers than the 'conventional' Langstroth hives used by commercial beekeepers.

The Bee-friendly Beekeeper: A Sustainable Approach, David Heaf, Northern Bee Books, 2010
Explores various approaches to beekeeping and explains the natural beekeeping approaches used in systems such as Warré and Kenyan top bar hives.

Perma-thoughts, 2

Here's an example of how my Permaculture course has changed my perspective on elements of the Patch:

On the northern boundary we're establishing a windbreak against hot, drying winds. At the moment, this consists of 15 Flinders Ranges wattle saplings. All but one are doing well, and should start to be effective in the next 24-36 months. I was quite pleased with this idea when I first thought of it: 'Good idea to create a microclimate, Steve!' I thought.

Will eventually be a windbreak: 15 tiny wattle seedlings , Aug 2011

Now, applying some Permaculture principles, I can see ways to make it a whole lot better:

Principle: Build diverse, stable ecosystems.

OK, a 15 x 2 metre windbreak (eventual mature size) isn't exactly an ecosystem. But what if I planted sheokes on the leeward side of the wattles, and grew a small-leafed (because not rampant) hardenbergia up the sheokes when established, and dug a swale to catch water runoff, and sowed the bank of the swale with dichondra and native violets, and planted blueberries in the lee of the windbreak? And put logs in the swale to provide habitat for lizards and amphibians?

Would this be an ecosystem, or just a collection of plants and landscape features? Let's have a look:

The wattles and the sheokes together will make a more effective windbreak; both are nitrogen fixing. When they are cut back (mulch for the veg beds), some of their root mass will also die off, making nitrogen available to the soil. Hardenbergia is also nitrogen fixing, so we have three plant species improving the soil. Blueberries on the leeward fringe of the windbreak will benefit from the added nitrogen, and also the acidic environment provided by the mulch of sheoke needles.

All of these are flowering plants and will provide forage for bees and nectar-eating birds. In addition the swale should become an ephemeral wetland, attracting the numerous frogs from the surrounding area - we're lucky to have two established wetlands to the northeast and northwest of the site.

So this begins to look like a functioning ecosystem, with beneficial interactions between the various species. In time further species would be introduced (or colonise by themselves) and it would become more diverse.

Principle: Every element of a design should function in many ways.

This is also referred to as 'stacking' functions. How does our windbreak fit in with this?

As envisaged above, it now serves the following functions:

• reduces the impact of hot, drying winds
• provides mulch for veg beds
• provides forage for bees (pollinators, suppliers of honey)
• provides habitat for insectivorous birds, reptiles and amphibians (pest control)
• provides fruit
• improves soil nitrogen
• improves water infiltration
• removes the need for mowing (saves labour)

Now, not all aspects of the plan will turn out as envisaged. For example, it may be that blueberries just won't flourish where I want them, so I would have to use other berries. That would tie in with other Permaculture principles:

Apply self-regulation and accept feedback.
Use small and slow solutions. (Otherwise referred to as incremental design.)
Creatively use and respond to change.

Perma-thoughts

For some time now I've been grappling with questions like the following:

• What do I want from all this food-growing activity? Is it just a hobby or a way of life?
• How can I get better at this and what does 'better' mean?
• Isn't backyard vegie growing mere escapism when we're laying waste to our entire planet?

Then I did an intensive two-week Permaculture course at Milkwood Farm near Mudgee, NSW. For two weeks I was thrown together with some really bright and knowledgeable people from many different walks of life (from cattle farmer to market gardener to software engineer), under the gentle guidance of two inspiring teachers.

I was rather sceptical before the course, and did worry about it being a massive waste of time and money. Not to mention the fossil fuels to get me to Mudgee and back. I don't like systems of thought that provide pat answers to difficult questions. I also had a whole heap of preconceptions about the course content, ranging from herb spirals to mandala gardens.

I now realise that Permaculture isn't like that; rather it's a set of methodologies, attitudes and principles that I can use in the design of productive systems - like a vegie garden, for instance. It has deepened my understanding of what a garden (or a productive landscape) is and can be. It has even given me some damn good answers to my three questions.

If you want to know what they are, you'll just have to do the course ;)