A biodiverse forest that is stacked in space and time thus abundantly yielding food and other outputs including building natural capital. Seven layers or so are developed to give yields early on in the system and all throughout its life as it matures. In essence, Vines drape on trees, herbs grow next to shrubs, and roots are dug when appropriate. Meanwhile vegetables are interspersed producing quickly while groundcovers spread to protect. Support species are highly integrated to develop soils and push the succession forward quickly. Edge is always remembered with maximum production in this system being one where there is not a completely closed canopy. Nuclei developed early on in the system, such as a tree guild, merge over time to form a holistic ecosystem. Animal integration is warranted and evolves, as the system gets older. Prepatory earthworks and soil repair often accompanies the implementation phase. Chop and drop and cycling of the layers over time are the main management tool as well as plant propagation for biodiversity and the stability and resilience that that brings.
Philosophy and Principles
The food forest is a palate of climate specific plants and animals that is adapted to each site and context. While it doesn’t produce a concentrated calorie resource like monocultures, it does however produce a range of food crops as well as medicine, fiber, fun, fuel, fodder and fertility. So beyond this yields, there are many other important ecosystem functions that it performs like building soil, promoting biodiversity and completing the hydrological cycle. This building of natural capitol makes it a far superior system of food production in comparison to the monoculture/lawn that dominates agriculture/ landscaping today. Furthermore, the food forest system is a historical one, whether it is the small European yard system or virtually the whole of the eastern deciduous forest of North America. Both were managed with sustainability and abundance in mind but different scales and techniques accompanied their development and management. Thus no two food forests are alike, there is no specific recipe, and the palate of plants to choose from depends on the artist. It is one of the designs that Agroforestry once recommended but the literature seems to be moving away from it even though its popularity grows within permaculture.
The 11 principles of Mollison’s Introduction to Permaculture book (summary here), can all be seen in the permaculture element of food forests or forest gardens. The main frame is the small scale intensive principle which encompasses space and time stacking. This principle facilitates the flow of energy to be cyclical and full of rhythm to let the system evolve in a spectacular fashion. By planting for diversity, guilds are formed and yields are harvested at different times. The system is based off of the architecture of the local forest allowing a biomimicry to take place. The plant palate is extensive in any given climate and creates a design challenge that classically melds imagination and information. From developing edge to energy cycling, from using plants that are multifunctional to using biological resources, food forests allow us to creatively interface with the principles.
Building on the principles, a design on paper or in the field should be created that follows a design process. This gives you a systematic approach to the implementation and its subsequent management. A vision is created and the site and personal resources are assessed and allow for the next phases to flow. Conceptualizing a spaces growth over time is a fun exercise but does require good plant knowledge as well as a creative impulse. Through the conceptual phase, the design comes from refining and always balancing the ethics of permaculture.
The main thing to think of is to overplant or space things even wider to ensure long term yields from the understory. If you choose to overplant, know that biomass cutback overtime must take place to make sure all the canopy has its proper space. This means when you look up plant spacing of say a semi dwarf apple tree and it says 5 m, you can either plant it at 2.5 and get more yields early on the system from that particular crop or space it to more like 7 m. This later strategy will cast shade below in the long-term but not form a closed canopy again bringing light down into the system. Both systems are valid and other element insertion like animals or earthworks will help to determine this. See the sequence below on overstacking and seeing how a food forest evolves over the years.
Another big decision is what will be your anchor species. This looks mainly at the canopy and sub-canopy species which builds to your lower levels. These lower levels, as well as any of the other layers, can be filled by nitrogen fixers which will be part of your fertility strategy as they are support species. How you arrange them leads to guild arrangement and the little mini ecosystems that creates checks and balances on the micro and macro scale.
In your plan also account for your water and think of how you may have to alter the land to be more receptive to water (regenerative earthworks). This accounts for the fact that you are wishing to accelerate succession and a
forest inherently infiltrates more water than other conventional agriculture systems. After that, also plan in your access of paths and roads as to facilitate the flow of materials and people. It’s really important to remember that each guild formed becomes like a garden bed which is not to be stepped on ideally. How will materials flow through the site, how will the nuclei grow, and how will chop and drop evolve the site? Sometimes defined plans change over time as the system evolves and some people choose to simply layout the access based on how foot paths naturally sprout up on the site.
As part of the assessment phase of the design process, the principle of energy efficient planning and tools like a sector and flow analysis will greatly aid this phase and strengthen the design through more functional interconnections. With that, element interaction is
perpetuated through also looking at zones. For example a strong wind sector speaks that your food forest needs an established windbreak first. Wind is very dehydrating and damaging to certain crops and the implementation of a food forest might hinge on dealing with this sector. Also with wildlife how will you block or channel animals like deer or wild goats? Also with element interaction will some water element like a pond of some size be in there. The scoop and drop of aquaculture systems can greatly aid the fertility of the site as well as be a spot of biodiversity to assist in pest control.
Also the assessment and leveraging of microclimates is an important part of a complete food forest design. Siting tree crops appropriately can lead to healthier growth and pushing the limits on zone hardiness. This also leads to structures like trellises which alter microclimates. I also like to incorporate social space into designs so that the food forest can also be experienced with a fun perspective.
Remember that a design also accounts for the fact that not everything is planted out at one time normally. Consequently, design with phases of implementation which is tied back to your assessment of both physical and personal resources.
Food forests are often associated with a seven layer system coined by Robert Hart some years ago. In my observations over the years, I feel like two more need to be added. Classically the seven layers are the following with the two added ones in bold:
I add the bush and grass layer as I find that in forests there is a woody layer that is taller than the classic clambering brambles that I would include in the bush layer. Like in the forest that I manage in Kentucky for broad acre food forestry, there is the multiflora rose, blackberry and black capped raspberry that I feel can’t be in the same layer as non native bush honey suckle or natives like Paw Paw, Serviceberry or Spicebush. They are not at the sub canopy level either as Red Maple, Box Elder and Wild Black Cherry occupy that layer. Meanwhile, the canopy is dominated by Shumard Oak, Burr Oak, Shagbark Hickory, Pignut Hickory and Black Walnut. Vines of poison ivy and wild grape clamber over the trees giving valuable wildlife food. The forest floor is full of herbs that flower when light is available in early spring and give way to another set of summer and fall herbs. Some of those include medicinal and culinary herbs like Bloodroot and Ramps which teeter on the rhizominous level. Grasses form on the edges where there is more light and the wetlands grass of Phragmites grows prolifically by the waters edge.
Furthermore, in Portugal at Terra Alta where I have worked since 2009, the cane grass known as Canas is such an important part of the food forest that I must include it as well. While not
edible for ourselves, animals do enjoy its fresh growing tips and is a major chop and drop species. It produces a great fungal resource for the trees as well as being an excellent windbreak. Moreover, it’s building material can be used for trellises and even social space including houses. On site we also have pampas grass, bamboo, sugar cane, and lemongrass which we cultivate directly. Meanwhile a myriad of annual grasses grow as well as bunching and running ones which light up in the rainy months in the mediterranean. They become part of our fertility strategy either as green or brown material. Thus grasses should be included in the discussion with bamboo’s also being such an important part of tropical permaculture.
However each food forest is different and not everyone is going to have an incredibly tall tree that forms the canopy layer. So sometimes species that are normally considered a sub canopy tree move into the canopy. This depends on the size of the area and the resources of the land. So while the layers give a framework it’s merely a guide not the rule.
Once the design has been done with the layers all accounted for, or as many as possible, the implementation phase must be enacted. Project management aids in this process ensuring that all materials, tools and labour are accounted for. If clever, months of preparatory
work will be done to ensure a low cost approach to this systems development. Because food forests lean more on the fungal side of the soil biology succession line, hot compost piles should be built with an adequate breakdown time of three months to build soil beforehand. This will allow you to fertilize immediately, add organic matter which helps with water, and repair the broken soil food web from the digging or even earthworks parts of establishment. Earthworks can greatly aid the establishment as well because ensuring a good hydrological cycle is vital. Terracing, swales, rain gardens and the like lend to the Permaculture phrase “water, access, structures”. The structures part refers to the trees themselves and designing how they will be passively (earthworks) or actively (irrigation piping) watered. Accounting and manifesting the water is
crucial to the investment that is building a food forest and the energy intensive aspect of set up and early years management. Structures can also refer to trellises or social spaces so be sure to also line that up appropriately in the implementation phase.
Also plants can be propagated especially the smaller layers with a focus on the herbaceous layer. This is where costs build up at nurseries as you need many more herbaceous plants than canopy trees to build the guilds and create a resilient ecosystem around each tree. This cultivated ecology depends on diversity and root division, cuttings, layering and seeds all help. Don’t forget the nitrogen fixers on all levels and growing these out before hand dramatically helps in the establishment process. Furthermore, when implementing your system you can use the principle of biological resources and its subset known as animal tractors to prepare the ground. They can covert present biomass into fertility and clear vegetation for you reducing the labour involved in establishment.
Finally nursery purchases must occur which is also where appropriate budgeting takes place. Grafted fruit and nut trees can get expensive from commercial nurseries but finding local producers at markets dramatically cuts cost. Remember the principle of small scale intensive and not spreading out too quickly as this investment of time and plant costs should not be squandered by taking on too much at a time. Planting the trees and other layers means management of the system including watering so match that with your time and water resources. Again develop the nuclei and let them merge. Its much more efficient this way rather than spreading out too quickly. Recognizing the need for phases of implementation creates a sense of doing what is accomplishable in one year and making sure you can take care of the system fully. Wasting money on spreading out too quickly is folly and build the system with natural rhythms.
To let the nuclei merge over time, plant propagation is furthered to evolve the system quickly. Digging up comfrey and replanting based of its exponential growth of its extensive root system allows one to spend frugally at the beginning. Plant propagation of say cuttings can also be done in an on-site nursery timing planting season appropriately. As the system evolves remember to keep planting the layers in successional planting. Again not everything is planted at once if the you embrace the idea of nuclei merging. You will see things die, seeds of plants spread themselves, and find gaps in the system where you need to keep planting. It is a truly difficult thing to imagine fully in the design phase which is why the re-evaluation phase is so crucial. This builds off of protracted and thoughtful observation (PATO).
Another management technique is to rotate animals through the system. If the system is young, chicken tractors can often fit in between the guilds. Design this system in if you have that will and intention so that the mobile chicken house can help with managing the spaces in between and spreading fertility. It also will help with further establishment and the use of the chicken tractor will phase out over time unless the system is in straight lines and borders on being more like a fruit or nut orchard. As the system matures chickens can free range and tree roots can be protected with a rough or stone mulch. Ducks and geese can also take advantage of falling fruit earlier in the system than say pigs. Over time pigs can enter and are part of pest control of the guild. Many pests of tree crops build from fallen fruit that is not harvested but pigs will happily pick all of these up. Furthermore, cycling of biomass is one of the most important management techniques out there. Chop and drop of dynamic accumulators and nitrogen fixers
in relative location to the tree crops will continue to bring nutrients and fertility by stimulating the soil food web. This also allows more light to enter the understory as nitrogen fixing trees and shrubs are coppiced. Their biomass is rolled back into the system and builds carbon rich soil which lessens water and increases plant health and pest and disease resistance. Don’t forget the tree pruning that most tree crops dictate. We try to intervene as little as possible but giving appropriate shape, air flow, and cutting out of dead, diseased, dying, crossing and those growing back into the middle are good general rules of pruning.
Overall, it’s a fun symphony to orchestrate and I hope this article is a beginning to you going out and doing it.
Written by Doug Crouch