Forest gardens

Forest gardens (also termed food forests, or edible forest gardens) are form of sustainable agriculture that mimics natural woodland ecosystems. All the plant species in a forest garden are of direct or indirect benefit to humans. The main yields are edible food crops, along with lesser produce such as plants used for fiber, timber or medicine.

Forest gardening involves polyculture planting, ideally to create mutually beneficial relationships between neighboring plants (guilds). Sustained by the delicate yet powerful balance of natural living cycles, the multiple layers of a forest garden provide for each other the same way the layers of a natural forest do. In this regard, forest gardening fosters biodiversity. Careful planning will also take into account the succession that may take place in the forest garden system.

Some plants are used to attract beneficial insects or birds. Others work to nitrogen fixation, build soil, or simply help keep out weeds. Vines on trees, shrubs, add another layer of growing space for edible fruits such as kiwi and passion fruit. Plants support one another as they store energy in their roots for later harvest and winter storage and when properly arranged help retrieve and disperse deep lying nutrients for each other.

The various existing forest gardens around the world can be categorized by age (recent or established) or by the climate (temperate, arid, or tropical).

It is an ancient form of agriculture that has been practised in some parts of the world since prehistory. The term forest gardening was coined by Robert Hart in the 1980s, after which the technique was adopted by key figures in the establishing permaculture community. At present, forest gardening has grown in popularity, and the theory and knowledge base has been substantially expanded by proponents within the permaculture community and other dedicated experts.

Definition and Terminology[edit | edit source]

Several closely related terms exist for this technique, such as forest gardening, food forest, (edible) forest gardens, woodland gardening, woodland edge gardening, forest farming. They all refer to broadly the same thing, although some argue that certain terms are more accurate. This article uses the term forest gardening as this seems to be the most frequently used term. An exact definition of the technique in precise language might be:

"An anthropogenic multistrata polyculture mimicking the layers of natural mid-succession stage woodland ecosystems and supporting biodiversity and resilience. Such systems are almost always operated on general organic farming principles, and tend to be subsistence level farming rather than being economically viable in terms of selling a yield. The system is however more sustainable compared to industrial farming. The system is largely self fertilizing and produces many yields at different times of year, mainly edible crops but also timber and other non timber forest products such as medicinal plants, soaps, etc."

Forest or Woodland?

Woodland gardening is a less commonly used term than forest gardening, but the terms are synonymous.^[1] Some argue that it is more accurate to use the term woodland rather than forest, since the latter usually implies a high density of trees with mature and closed canopy layer giving continuous shade and very limited light for other plants. Woodland usually refers to lower density of trees with understorey of shrubs etc. with lots of sunlight and limited shade.^[2] Furthermore, forest usually implies a large area,^[3] whereas most forest gardens are very small in comparison with the scales of commercial forestry and industrial agricultural. In theory, forest gardens could be any size.

Woodland Edge Garden

The edge of a forest has more diversity of species due to more availability of light. In nature, as woodland gradually grows from ecosystems such as grasslands (termed "succession"). The expanding edge of the woodland contains some species from the wood, some from the other ecosystem, and some which are specialized for the woodland edge and move overtime (e.g. alpine strawberries). Consequently, the edge of the forest can be the most productive area and more food can be grown. This term refers to forest gardening idea on a very small scale, as small as a 1 m or 1.5 m wide bed along the northern side of a garden. Generally this type of garden has no full size trees, and the low tree layer acts as the canopy. Because it is a narrow strip, plenty of light is available from the side.^[2]

Food Forest / Edible Forest Garden

Another very commonly used term is "food forest" or sometimes "edible forest garden". While the main purpose of the forest garden is food production, there tend to be secondary uses and yields, such as medicinal plants, dyes, poles/canes, basketry materials, soaps, firewood and timber.^[3] Therefore it could be argued that the more general term forest gardening is more appropriate.

Agroforestry

Agroforestry is the intentional integration of agriculture (crops, livestock) and forestry (tree crops). Six main agroforestry practices are recognized: alley cropping (crops grown in between rows of trees), riparian forest buffers (natural or re-established strips of trees, shrubs and grasses), silvopasture (livestock grazing under trees), windbreaks (linear tree plantings to reduce windspeeds and create a sheltered microclimate), and forest farming (discussed below). Some recognize forest gardening as a main practice of agroforestry, but most agroforestry institutions do not.

Forest Farming

This is a type of agroforestry closely related to the idea of Forest Gardening. However forest farming tends to use only 2 or more species. There are usually only 2 species involved compared to the extensive range of species in a forest garden. Examples would be farming of shiitake mushrooms on logs under a carefully managed canopy layer.

Potential benefits[edit | edit source]

Compared to conventional methods, food forests may:

• have a higher yield per area. An abundance of produce can be shared with friends and neighbors or to turn a small profit.
• reduced reliance on a market with varying pricing and demand for a single product.
• fewer pests, less maintenance, no artificial chemicals.
• create wildlife habitat.

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Forest Gardening vs Industrial Agriculture[edit | edit source]

Industrial agricultural practices by comparison tend to involve genetically modified monoculture. Monoculture means less biodiversity, and less resilience to pests and diseases or climate changes (e.g. increased drought). While genetically modified crops may have the potential to alleviate hunger in some parts of the world, there may be unintended health issues. To create a monoculture, the existing ecosystem has to be destroyed, which means habitat loss and possibly even extinction for some species. Typically forests have been cleared to create arable land or pasture. Without the root systems of trees and litter-fall, soil erosion is a major risk.

Intensive cultivation of crops with high nutrient requirements, and the continual harvest and removal of the nutrients stored in the crop leads to a great reduction in soil fertility. Fertilizer has to be used, which can lead to leaching of fertilizer into the water cycle, and to problems such as eutrophication. A monoculture system is very vulnerable to pests and diseases, so synthetic insecticides and herbicides must be used to maintain a yield. Pests such as insects also quickly develop resistance, so stronger chemicals have to be used. Traces of such chemicals may be carcinogenic or otherwise harmful to humans, or indeed other species. Such toxicity tends to concentrate higher up food chains, e.g. predatory animals being worst affected.

A forest garden produces many small yields and different times. It may superficially seem that a greater yield and more efficient harvest can be obtained from monoculture relative to a complex polyculture like a forest garden. However, there are huge energy inputs when considering that non renewable energy sources are needed at many stages in industrial agriculture and the other industrial systems and infrastructure on which it depends. Forest gardening with a focus on self fertilizing, perennial species, companion planting (guilds) and low maintenance has relatively low energy input. Therefore if defining the efficiency of an agricultural system as a ratio of the energy output relative to energy input, forest gardening is more efficient compared to monoculture.^[3] Industrial agricultural practices may become increasingly difficult to sustain with rising energy costs, increasing burden of human population and climate change.

Another way of looking at forest gardening is to consider that the closer the agricultural system is to the native climax community, the less disruptive and the more energy efficient it will be. To change and maintain a piece of land in a way that is very different from the natural climax community, a lot of energy has to be expended and there is less energy efficiency. For temperate zones, the climax community tends to be woodland.^[3]

Temperate vs subtropical and tropical forest gardening[edit | edit source]

At the equator, electromagnetic radiation from the sun has less volume of atmosphere to penetrate, and the angle of incidence with the surface of the earth is more perpendicular. Hence the energy received per unit area (solar irradiance) is greater at the equator. Due to the tilt of the earth's rotational axis, daylength variations are minimal year round near the equator. Due to the curvature of the earth, regions within the temperate zones present a non-perpendicular angle of incidence to radiation from the sun, and there is a greater volume of atmosphere to penetrate. There are greater seasonal variations in daylength the further north or south you go from the equator, creating warm and cold seasons.

Close to the equator in tropical zones, there is more light available for photosynthesis. In ecosystems such as a tropical rainforest, great potential for photosynthesis combined with year round warm temperatures and high precipitation creates highly favorable conditions for plant growth.

In contrast, in a temperate climate, there is less potential for photosynthesis. The cold season triggers many plants to become dormant, and deciduous plants drop their leaves to prevent water loss by evapotranspiration. So there is a period of dormancy and a distinct growing season for many species.

This important difference in climate conditions means that forest gardens in tropical and subtropical zones may be designed with a greater density of species, stacked vertically in space. Some claim that forest gardening in climates such as Kerala or Haiti is relatively easy.^[4] Careful ground cover or mulch is very important to protect the soil from baking in the sun.^[4] In a temperate forest gardens, the canopy layer must be relatively sparse and open, otherwise not many plants would thrive due to not enough light reaching the understory. A very common mistake among temperate forest gardeners is to plant the canopy trees too close together, and not take into account the area the canopy of each tree will be when it is fully mature.^[4] While a densely planted forest garden will allow for lower layers to establish and thrive in early years, the more canopy layer matures the less light will filter through to lower layers, seriously hampering their productivity. Some claim that Hart's forest garden was planted too densely.

As such, some will specifically describe temperate forest gardens as mimicking mid-succession woodland ecosystems (sometimes described as immature or young woodland) or a woodland edge.

Layers[edit | edit source]

Conceptually forest gardens have multiple layers, also termed strata or stories. This idea was borrowed from the scientific classification of vegetation in woodland ecosystems according to the different heights at which plants grow. The different layers of a woodland are generally occupied by different plant species in distinct but typically mutually supportive communities (stratozones, Read more: [1]). In a forest garden, each these layers consist of species carefully selected to be of direct or indirect benefit to humans. Classically Hart described 7 layers. Others such as Whitefield simplified this to 4 (Tree, shrub, vegetable and vertical). Crawford also acknowledges that the groundcover and herbaceous perenial layers are not always distinct.

• Canopy layer - the largest trees.
• Low-tree / Understory layer - trees smaller than the canopy layer but larger than the shrub layer. smaller nut and fruit trees on dwarfing root stocks.
• Shrub layer
• Herbaceous layer
• Rhizosphere or 'underground' dimension of plants
• Ground cover layer
• Vertical layer - vines and climbers.

Two additional layers have since been proposed:

• Aquatic/Wetland Layer
• Mycelial/Fungal Layer

Example Forest Gardens[edit | edit source]

List of forest gardens in the UK, Europe and North America (Agroforestry & Forest Garden Network) [2]

"Forest Garden plots are to be found in various research trials and in small yards throughout the temperate world. A number of studies have looked at forest gardens in the humid tropics, and they can be a significant source of minerals and nutrients, as well as providing income and food security for the owners. Forest Gardens appear in many different societies in the wet tropics and go under various names including: Home gardens in Kerala in South India, Nepal, Zambia, Zimbabwe and Tanzania; Kandyan Forest Gardens in Sri Lanka; huertos familiares, the "family orchards" of Mexico; and pekarangan, the gardens of "complete design", in Java."[wikipedia.org/wiki/Forest_Gardening]

USA[edit | edit source]

The Rahma Free Health Clinic Edible Forest Snack Garden - http://web.archive.org/web/20120419072053/http://www.indiegogo.com:80/Rahma-Free-Health-Clinic-Edible-Forest-Garden

The Rahma Forest Garden (for short) is an urban forest garden project in Syracuse, NY that will be located on the grounds of a new free health clinic that is opening this spring - bringing the mission of the health clinic outside it's doors using perennial Permaculture forest garden design - we hope this will be a model for health care sites everywhere in years to come. Providing a resilient food resource in the 'food desert' of the Syracuse south side. And contributing to the extensive green infrastructure goals of the city. A project of The Alchemical Nursery - http://www.alchemicalnursery.org

The Huntington Ranch - http://huntingtonblogs.org/theranch/2010/12/food-forest-intro/

The Huntington Ranch is a new experimental exhibit at The Huntington: Library, Art Collections and Botanical Gardens (http://web.archive.org/web/20131105133228/http://www.huntington.org/default.aspx) located in San Marino, Ca. The low maintenance food garden technique is being applied, tested and scrutinized to help evolve the food forest/gardening best practices. Reducing maintenance, creating an ecosystem with active synergies and ensuring a measured increase in soil quality are some of the main goals in the exhibit.

Wetherby Edible Forest - http://web.archive.org/web/20170903053306/http://www.backyardabundance.org:80/AbundantLandscapes/WetherbyEdibleForest.aspx

The Wetherby Edible Forest (in Iowa City, IA) inspires our community to gather and grow healthy food in ways that rehabilitates our local ecosystems while increasing equal access to food. Join us to improve public health by regenerating our public land into an edible forest ecosystem. We work to reduce agricultural climate impact, improve our local food security, provide educational opportunities, and celebrate growing food for the benefit of all species. All food is free for harvesting and eating. No synthetic pesticides or herbicides have been applied.

Growing Food Forests in Seattle - http://www.urbanfarmhub.org/2010/03/growing-food-forests-in-seattle/

As a part of Transition Seattle - "an alliance of organizations and individuals who believe in living within the limits of the earth's resources, with healthier lifestyles, and in resilient, creative, just, and collaborative communities." This alliance goals and achievements include passing laws to secure land for sustainable food production and establishing these sustainable food production areas, organizing care taking and distribution. From food bearing street trees to urban food forests there is a growing movement in Seattle which wants to see it transformed into an urban food forest.

UK[edit | edit source]

Wenlock Edge, Shropshire

This was Robert Hart's forest garden, no longer open to the public. Following his death based on aerial images it seems new owners have partially removed the forest garden.

Agroforestry Research Trust Research Sites, Devon

3 sites managed by the Agroforestry Research Trust exist in Devon. The oldest is about 25 years old, near Dartington.[3]

Bangor Forest Garden, Gwynedd

Run by volunteers. Located North East to Bangor at Henfaes Research Centre, Abergwyngregyn, Gwynedd LL33 0LB.[4]

Central America[edit | edit source]

Food forests have existed in Central America for thousands of years. The El Pilar Forest Network (http://www.mayaforestgardeners.org/forestgardening.php) continues this tradition today.

"We often think of the rainforest as untouched by humans, or "virgin forest." In reality, it can be understood as the garden of the ancient Maya: the product of millennia of management by forest gardeners who cultivated the cycle of milpa, forest garden, and forest. In fact, 90% of plants in the forest are useful to humans, indicating considerable human influence. The Maya Forest remains the second most biodiverse place in the world (the Amazon forest is the first). The legacy of the ancient Maya forest gardeners is continued by the Maya farmers of the El Pilar Forest Garden Network."

South America[edit | edit source]

The tribes of Ancient Amazonia lived within vast "garden cities" with shaping the landscape to suit sustain themselves while simultaneously enriching the already fertile soil. It appears much of the apparently useful planting utilized by the indigenous tribes found within the Amazon rain forest have been predetermined by ancient civilizations. The Amazon is today is subject to record logging, oil pollution and many other externally guided influences of resource depletion and ecosystem degradation.

Proponents[edit | edit source]

• Robert Hart - [5]
• Bill Mollison - [6]
• David Holmgren - [7]
• Geoff Lawton - [8]
• Sepp Holzer - [9]
• Martin Crawford - [10]

References[edit | edit source]

Learn More[edit | edit source]

Books[edit | edit source]

• Woodland Gardening (Plants For A Future)
• http://web.archive.org/web/20200214164339/http://www.centerforagroforestry.org/pubs/training/chap7_2015.pdf

Videos & Films[edit | edit source]

• How to make a Temperate Forest Garden (Part 1,Part 2). Maddy and Tim Harland describe the planning and design of a forest garden, with reference to their own forest garden in Hampshire, UK, which is over 20 years old (brief excerpt of a visit to the same forest garden: [11]). They stress that the main difference between temperate climate forest gardens and those of the tropics is that there is less light available and so the trees must be more openly planted to allow light through to the lower layers. The mature spread of the plants is also an important consideration when drawing out the spacing between plants, otherwise they warn that pruning will be a constant task.
• Establishing a Food Forest the Permaculture Way (Geoff Lawton) [12]
• Creating Gaia's Garden (Toby Hemmenway). Lesson 3: Plants For Many Purposes. Permaculture educator Toby Hemmenway gives a presenatation about companion planting (guilds) and how to design forest gardens. Also discusses Hugelkultur and aquaponics, although more content on forest garden begins again at 51:45. [13]
• The Garden - A documentary on an urban food forest and it's struggle to survive in an environment of capitalistic enterprise of the poor & questionable political interests. "From the ashes of the L.A. riots arose a lush, 14-acre community garden, the largest of its kind in the United States. Now bulldozers threaten its future." - http://www.imdb.com/title/tt1252486/

Articles[edit | edit source]

• Forest Gardening - category page at Plants for a Future.[14]
• Central American Forest Gardens' - http://www.waldeneffect.org/blog/Central_American_Forest_Gardens/
• Anthropogenic forests in the Amazon - http://www.waldeneffect.org:80/blog/Anthropogenic_forests_in_the_Amazon/
• Tropical Forest Gardening - http://www.waldeneffect.org/blog/Tropical_forest_gardening/
• Mother Earth News - this website has many good articles about forest gardening - https://www.motherearthnews.com/search?phrase=forest+gardening
• Amazon Rainforest was Giant Garden City - http://web.archive.org/web/20131015204032/http://www.telegraph.co.uk/science/science-news/3350474/Amazon-rainforest-was-giant-garden-city.html

Organizations[edit | edit source]

• https://www.agroforestry.co.uk/
• https://apiosinstitute.org/
• http://edibleforestgardens.com/
• http://training.trees.org/en/resource (Forest Garden Training Center - this website has a freely available Technical Manual, mainly aimed at non temperate climate forest gardening)

See also[edit | edit source]

• Apiary design for a forest garden
• Fruit and nut harvesting net

External Links[edit | edit source]

• http://www.permaculture.org/nm/index.php/site/Permaculture-Food-Forest/
• http://www.permaculture.org.au./
• http://web.archive.org/web/20160308224746/http://burlingtonpermaculture.org/infosheets/edibleforestgardensarticle.pdf
• http://web.archive.org/web/20190421030758/https://articles.extension.org/forest_farming