Forest gardens, also called food forests, are cultivation systems that mimic the structure and design of a forest ecosystem. Like forests, forest gardens are composed of several vegetation layers with trees, shrubs, herbs and vines growing in the same place. The difference between natural forests and forest gardens is that the latter are specifically designed to produce food, medicines, wood, or other products for human consumption.
In this post, I explain the main principles of forest gardening and I discuss whether or not forest gardens are a viable farming practice in a temperate climate. I divided the blog post into 4 different topics:
The main principles of forest gardening
The benefits and limitations of forest gardens
Are forest gardens a viable farming practice in a temperate climate?
Conclusion
1. The main principles of forest gardening
The 7 vegetation layers
Forest gardens aim to maximize sunlight absorption and increase the resiliency of the system by having a high plant diversity. In theory, forest gardens should have 7 different vegetation layers, like a forest ecosystem. Each vegetation layer fulfills a unique set of ecological functions and they increase the leaf area for maximal sunlight absorption, which increases the overall productivity of the system. The 7 vegetation layers are the following:
Tall trees
Low trees
Shrub layer
Herb layer
Ground cover layer (ground cover plants)
Vine layer (climbing plants layer)
Root layer (root plants)
The different vegetation layers in a forest garden
Source: Illustration by Daniel Larsson
In practice, you don't have to establish all seven vegetation layers to have a thriving forest garden. The key is to maintain high plant diversity and a dense vegetation to maximize sunlight absorption.
Using plant species that are best adapted to the different areas of the land
Forest gardens are agroforestry systems characterized by structural variability, plant diversity, and varying levels of shade. These factors create different microclimates that change over time. Thus, “forest gardeners” must thoughtfully consider where to place each plant species. Placing the right plant in the right location leads to a more efficient use of natural resources.
Focus on perennial crops
“Forest gardeners” use more perennial crops such as fruit and nut trees, berry shrubs, and perennial vegetables, than annual crops. Unlike annual crops, which must be planted every year, perennial crops provide a reliable source of food each year with minimal inputs. Their deeper root systems can access nutrients and water from deeper soil layers, reducing the need for irrigation and fertilizers.
Improve the soils fertility by adding lots of organic matter
“Forest gardeners” create a thick vegetation and add its organic matter to the soil to improve soil fertility over time. They use plants that produce a lot of biomass and plants that can draw nutrients from deeper soil layers. Additionally, they use a technique called 'chop and drop,' where leaves and branches are cut and spread throughout the system to enrich the soil with organic matter. This technique, along with a thick vegetation and a high plant diversity, improves soil fertility over time.
Plant and structural diversity of a swedish forest garden
Source: Forest garden at Naturbruksskolan Angereds gård in Gothenburg, Sweden. Picture taken by Mauricio Sagastuy
Mimic the natural succession of a forest ecosystem
“Forest gardeners” reduce their workload over time by mimicking the natural succession of a forest ecosystem. The forest garden gradually moves from an early level of natural succession to a later level of succession until it reaches a stage where little management is needed. At this point, when the forest garden has matured, it will produce its own fertility by recycling the nutrients in the system.
2. The benefits and limitations of forest gardens
Benefits:
Nutrient self sufficiency: The trees and shrubs “pump” nutrients from deeper soil layers to the top of the soil via their leaves. Simultaneously, a dense vegetation adds more organic matter to the soil. Additionally, an undisturbed soil and high plant diversity promote the growth of mycorrhizal fungi and other soil microorganisms. These organisms make the nutrients more available for the plants, thus accelerating the nutrient-cycling process.
High biodiversity: Forest gardens tend to have a high diversity of plant species, ranging all the way from trees, to shrubs to a herbaceous layer. This diversity attracts a wide range of insects and other animal species.
Product diversification: Forest gardens can produce a wide variety of products due to their high plant diversity. The most common products coming from forest gardens are food, medicine, and wood. This diversity makes them less vulnerable to market changes.
Self regulated system: Forest gardens require less management over time. This is achieved by planting perennial crops, choosing the right plant species for the right location, and by mimicking the structure of a forest ecosystem.
Limitations:
Lack of efficiency: The high complexity and diversity of forest gardens can make their management less efficient.
Hard to mechanize: It is hard to mechanize a system that works with several plant species and many vegetation layers.
Knowledge intensive system: Cultivating different plant species in combination with one another requires specialized knowledge and expertise.
3. Are forest gardens a viable farming practice in a temperate climate?
As you could read in the principles above, forest gardens are based on useful concepts and ideas, like closed nutrient-loops, self-regulating systems, high biodiversity, and increased productivity through dense vegetation. When I have visited mature forest gardens I have seen that these ideas are not only theoretical concepts, but they do work in practice. Most mature forest gardens I have visited have closed nutrient loops, few pests and diseases, and they require little management once they have been properly established.
Forest garden with bananas in Spain
Source: Juan Anton´s forest garden next to Valencia, Spain. Picture taken by Mauricio Sagastuy
In my opinion, the downside of most forest gardens is that they are too complex and most owners aren't interested in producing food efficiently. Most forest gardens are usually treated as a hobby or as sources of food production for self sufficiency. There is nothing inherently wrong with this, both purposes are worthwhile endeavors to pursue. However, it is a bit of a shame that these wonderful systems aren't achieving one of the main purposes of agroforestry, which is to produce food efficiently for other people as well. That is why I believe farmers aren't so drawn to this concept, because their work is to produce food efficiently for millions of people. Farmers prefer to work with other types of agroforestry systems that are less complex, like windbreaks or silvopasture, because those systems are a better fit for their farming enterprises.
This doesn't mean that forest gardens aren't a relevant system for food production. Forest gardens can be a great way of producing food on a small scale in tropical countries or for self-sufficiency in temperate countries.
Forest gardens can also be economically viable in temperate regions. Some forest gardens I've visited in Europe generate enough income for their owners to make a living. These forest gardens tend to have more structure and be less complex than those intended solely as a hobby or for self-sufficiency. However, most forest garden owners also rely on additional income sources besides food production. Many supplement their income by creating plant nurseries, giving presentations, and conducting workshops on forest gardening.
Me in my school's forest garden, where I work as a teacher
Source: Forest garden at Naturbruksskolan Angereds gård in Gothenburg, Sweden. Picture taken by Mauricio Sagastuy
An interesting aspect of forest gardening is their potential to serve as test fields for agroforestry and gather valuable information for farmers. Since most forest gardens are established as a hobby, owners tend to experiment with different species, cultivars and techniques. This opens up new business opportunities and serves as a valuable source of knowledge for other types of agroforestry systems. By planting exotic species and new varieties, “forest gardeners” test what works and what doesn't work. This leads to a higher genetic diversity per plant species and the possibility to develop better varieties for different climates. That is why many “forest gardeners” have started plant nurseries, where they sell new varieties of trees, shrubs or perennial vegetables. This gives them a competitive advantage over larger commercial nurseries, which seldom offer lesser-known varieties.
If we could systematically collect the insights gained from experimentation in forest gardens, we would be further ahead in our understanding of which combination of plant species could work best for different climates and soils.
4. Conclusion
Agroforestry and forest gardening share many principles in common. Both practices aim at improving nutrient cycles, increasing the biodiversity, and using forest ecosystems as role models. However, a big difference between agroforestry and forest gardening is that most agroforestry systems are intended to be used for farming purposes. As a result, these systems are more willing to “sacrifice” a high complexity for a more efficient management.
An efficient management leads to higher profitability and to the ability to manage large pieces of land. In temperate climates, forest gardens are typically smaller, rarely exceeding 5 hectares. As their name suggests, these systems are usually managed as gardens rather than farms. Therefore, I don´t believe that forest gardening can be seen as a realistic farming model for temperate climates as farmers need to produce food efficiently on large scales. Other types of agroforestry systems are more realistic options for farmers in temperate climates.
On the other hand, I believe that forest gardens can play an important role for self sufficiency and for gaining knowledge about new plant species, varieties or plant combinations in temperate climates.
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