What is a Food Forest?

A "food forest," also known as a "forest garden," is a food production system which mimics the multi-layered nature of an actual forest or jungle. Unlike in a wild forest, where specific plant selection is left up to nature, in a food forest all the layers are either food producers or supporting species that turbocharge the food producers. Today we're going to examine the specific layers that comprise a forest so that we can begin to think about replicating those layers in our own food growing systems.

A Perrenial Approach

The food forest concept uses a perennial approach to food production. Perennial means the plants survive the winter and keep coming back year after year. In theory, a perennial system requires less maintenance with each passing year. There are actually food forests today that have existed for centuries!

Let's compare the food forest approach with the annual agriculture approach. The annual approach is typified by megafarms and, at the home level, annual gardening. Annual crops have to be replanted every single year because they freeze to death when the winter arrives. They require a full dose of work every year to start the garden over again, essentially from scratch. Actually it's even more work than that because annual crops drain the soil of nutrients each year so growing food is harder over time. 

Given the comparison, which would you prefer for your family? Would you be more comfortable in a Garden of Eden situation (minus the snake) where nature easily takes care of your needs year after year? Or you could slave away year after year growing annual crops. I use the word "slave" specifically here, because slave labor was primarily required specifically because annual crops require so much manual labor each year. Anyway, we think you'll agree that the Garden of Eden scenario is more enticing than the work-yourself-to-death method of growing food. 

So forests in general, and food forests in particular, have a multi-layered structure. We're going to examine each of the layers so that you have a better understanding of how the whole system works together. Each layer cooperates with the other layers to make a diverse and resilient system. There are roughly fifteen total layers in the forest, each of which represents a particular biological niche, and we will examine each of them now, starting with the tallest layers.


(1) The Emergent Palms Layer

The emergent palms are tall enough to poke through the canopy layer so that they can get access to sunlight. They look like a tall, thin pole with leaves clustered around the top of the plant. In a jungle environment, you can see them poking of out the top. 

Emergent Palms Poking Out Above the Canopy

In terms of food production, coconut trees are the most famous example of an emergent palm.

Coconuts

Coconuts

Palms seem to thrive best in tropical and subtropical temperature zones (i.e. warmer climates). Due to their shape, palm trees are commonly used in landscaping because they don't take up hardly any space at all at the ground level and they look kind of neat.

Palms in the City

(2) The Canopy Layer

Most large trees are part of the canopy layer. If the forest were a house, the canopy layer would be the roof of the house. The large trees that make up the canopy soak up the majority of the sunlight. Because of this, they form a dense layer of leaves at the top, where the light is good, and then these same trees have far fewer leaves closer to the ground where the lighting conditions are not as good. If you look at a forest or jungle from a distance, what you primarily see is the canopy layer because it blocks the visibility of the lower layers above. Here's an example of that:

Because the majority of fruit and nut trees are part of the canopy layer, most forest gardeners focus a lot of their attention on this layer. As a practical matter, because full-sized canopy trees are so large, you will probably be limited by the total area of your property when deciding how many fruit trees to plant. However, you might also be surprised how many trees you can fit onto a small urban lot. 

Oranges

Oranges

Grapefruit

Grapefruit

Apples

Apples

Peaches

Peaches


(3) The Sub-Canopy Layer

The sub-canopy, also known as the understory layer, is the third and final tree-based level. The sub-canopy is the smaller tree species in the forest. Because they live in the shade provided by the larger canopy trees, they do not require nearly as much light. Actually they prefer limited direct sunlight. In general, sub-canopy trees have larger, brighter flowers so they can stand out to insects given the more limited lighting conditions. 

A classic example from the sub-canopy level is the banana tree. The banana tree has huge leaves so that it can soak up the limited sunlight it receives. As we know, in the process it also produces a really nice edible fruit. 

Bananas

Bananas

A Cacao Bean

A Cacao Bean

 

Cocoa (also know as Cacao), the source material for chocolate, also grows as a tree in the sub-canopy layer. 

 

 

Cherries

Cherries

For the at-home food forest designer, an interesting option is using dwarfing or semi-dwarfing rootstock to make large canopy trees only grow to the size of sub-canopy trees instead. This allows you to fit more fruit trees onto your property. There remains a significant amount of debate around whether trees on dwarf and semi-dwarf root-stock are as healthy as their full-sized-root counterparts. For my own properties, I have decided to use full-size root stock on all my trees, but to keep the urban ones heavily pruned so the size doesn't get out of hand. Considering you only have to prune once every year or two with this approach, I find it more intuitively appealing rather than trying to constrain the size of the tree roots. 


(4) Oversized Grasses

Some grasses, primarily bamboo, have evolved to be a huge version what we usually think of as grasses. Grasses spread via an underground root network that expands like an underground net. The visible portion of these plants then "shoot" up from this root network. The density of the root network for these oversized grasses is so tight that they tend to be aggressive species which are difficult to effectively control. 

Bamboo

Bamboo

At first I was not aware that bamboo is actually an edible, but bamboo shoots are a common ingredient in chinese cuisine. Mature bamboo is also probably one of the world's most useful and versitile materials, with applications ranging from flooring in your home to cutting boards in your kitchen to scaffolding at a construction site. I use a lot of bamboo in my garden as a building material for simple structures such as trellises. I hope to experiment with this more in the future. 

For a future project, I'm planning to use bamboo as a fence around an urban food forest to help protect from tornado-force winds. Bamboo is fantastic in high wind conditions because the above ground portion can sway in the wind while the below-ground root structure remains stable in even the most adverse conditions. In my experience, minimizing wind disturbances for your fruit trees will help prevent the fruit from blowing off the trees before harvest time. 


(5) Shrubs and Bushes

The next shorter layer underneath the sub-canopy and not taken up by the oversized grasses is the shrub layer. Shrubs and bushes are smaller than small trees, but still relatively large at maturity. Large bushes can be as tall as an adult human.

A lot of berries grow on bushes and they can be an effective option for those of you who live in colder climates. Possibly because of their dense, relatively compact structure, they are better able to handle cold conditions than many of the larger fruit trees. 

Currants

Currants

Blueberries

Blueberries

Huckleberries

Huckleberries

Rosehips

Rosehips

In addition to being great food plants, many of them also produce very attractive flowers. Here is the flower from an Okra plant. Okra is a common ingredient in southern US cooking such as gumbo. I like eating it as a dehydrated snack. 

Okra - Flower

Okra - Flower

Okra - Edible Portion

Okra - Edible Portion


(6) The Herbacious Layer

The herbaceous layer is where herbs grow. They grow up from the ground but don't typically get as tall as a bush. The herbaceous layer is a great place to grow herbs for cooking. Depending on your climate, different herbs may survive the winter and some may need to be annually planted. Most leafy greens used in salads are part of the herbaceous layer. 

Cilantro

Cilantro

Japanese Spinach

Japanese Spinach

Kale

Kale

Chives, Basil, & Parsley

Chives, Basil, & Parsley


(7) Runners

While the herbaceous layer rises a little bit above the ground, runners move horizontally across the ground. Blackberries are a great example. The blackberry plant looks like a vine, but the vine moves along the ground rather than going up. 

Blackberries

Blackberries

Strawberries are also runners. Instead of a vine-like shape, they spread in all directions above the ground, creating roots at each new node point in the network. The strawberries themselves are usually barely lifted off of the ground by the plant. 

Strawberries

Strawberries

Most melon plants are also runners. 

Watermelons

Watermelons

Pumpkins

Pumpkins


(8) Climbers

Climbers are like runners that vertically climb instead of running horizontally along the ground. Climbers use the taller layers, such as the canopy trees, as a structure to support them while they grow vertically. Climbers are not able to hold themselves up on their own. Instead, they focus on grappling onto the vertical surfaces around them. 

This close-up is typical of how climbers grab hold onto other surfaces using a wrapping around growth motion. 

This close-up is typical of how climbers grab hold onto other surfaces using a wrapping around growth motion. 

Climbers also wrap around themselves, creating a rope-like strand. This green bean plant is a great example. 

Climbers also wrap around themselves, creating a rope-like strand. This green bean plant is a great example. 

Many but not all of the climbers are annual plants. Because of this, they grow extremely quickly during their growing season. 

Cucumber

Cucumber

Mexican Sour Gherkin Cucumber

Mexican Sour Gherkin Cucumber

However, not all climbers are annual plants. Example perennial climbers include grapevines and passion fruit plants.

Grapes

Grapes

The Flower from a Passion Fruit Plant

The Flower from a Passion Fruit Plant

Passion Fruit

Passion Fruit


(9) The Compost Layer on the Ground

If you've ever been in a mature forest, you know that you don't see very much bare earth. Instead, the ground itself is covered with fallen leaves, broken branches, and a variety of other natural items. The compost layer is the primarily recycling mechanism for the forest. Fungi in the compost layer are breaking down used materials into small enough components that plants can use them as nutrients again. 

pexels-photo-191037-2.jpeg

The flower from a fungus is called a mushroom. Mushrooms tend to be located in the compost layer because this is where the majority of the above-ground fungus resides. In the forest, you also see a lot of mushrooms growing out of decaying logs which are often found laying down on the ground. 

Shiitake Mushroom 

Shiitake Mushroom 

In an urban environment, mulching and composting are simulating this natural surface activity in the forest. As you establish your food forest, the leaves will drop once a year (depending on where you are), which will begin producing this natural compost layer. 


(10) Tubers and Root Crops

While most plants have roots that grow into the ground, a select group of plants grow their edible portions underground. These are the tubers. Carrots, Potatoes, Radishes, Onion, Garlic, and Ginger are all examples of plants whose primary edible component is underneath the ground. The stable temperature inside the ground allows these plants to more easily tolerate weather extremes. 

Carrots - In the Ground

Carrots - In the Ground

Carrots - Harvested

Carrots - Harvested

Onions, Garlic

Onions, Garlic


(11) Below Ground Fungus

There is also an invisible layer beneath the ground, which is comprised of Mycorrhizal Fungi. These are specialized fungi that act like a biological internet, exchanging nutrients between the roots of different plants to help the plants to grow. The Mycorrhizal Fungi look like tiny hairs attached to the roots of plants. Here is a microscopic zoom-in photo of a plant root with the fungi and then an artist's illustration:

While the fungus itself might not be easily visible, the effects on plant root growth are clear. Here are the results of a study in which one tree was grown in biologically dead soil (on the left) and the other, identical tree, was grown in "living" soil treated with  Mycorrhizal Fungi (on the right). Notice the tree grown in living soil has over twice as much root mass.

 
 

(12) The Aquatic Layer

Inside of a forest, you typically find one or more water sources such as a creek, river, or pond. The trees and animals use these water sources to ensure their vigorous growth. In addition, aquatic systems by themselves are some of the most productive ecological environments in the world. Fish and aquatic plants are sometimes able to grow faster than their land-based counterparts because the water minimizes the force of gravity that need to be overcome for growth. Birds love aquatic systems since they are the source of fish which many birds and people depend on for food.  

An interesting example of the aquatic layer is a wetlands. Wetlands are essentially flood zones that fill with water during a rain event and then drain over time. Aquatic wetlands are a huge water filtration system which cleans incoming water so that it can be utilized more efficiently by the forest. The area next to a wetlands, called a riparian zone, is especially fertile since it has the benefits of close access to water combined with a fertile soil upon which to grow. So the aquatic layer includes any plants that can tolerate very moist to submerged conditions. To an extent, modern aquaponics and hydroponics simulates this sort of aquatic wetland ecosystem. 

Catfish

Catfish

Sockeye Salmon

Sockeye Salmon

Mantis Shrimp

Mantis Shrimp

Duckweed, a popular fish food. It's the green on the surface of the water in this picture. 

Duckweed, a popular fish food. It's the green on the surface of the water in this picture. 

Taro, an aquatic plant with an edible root that, when prepared properly, resembles chocolate

Taro, an aquatic plant with an edible root that, when prepared properly, resembles chocolate

The edible root portion of the Taro plant. 

The edible root portion of the Taro plant. 

Waterlilies, one of many edible water plants

Waterlilies, one of many edible water plants


(13) The Pollination Layer (Insects)

While most of the previous layers focused on plants, bacteria, and fungus, the final three layers primarily focus on the animal kingdom. Insects are some of the smallest animals, but they have a critical role. Many insects act as pollinators, which means they fertilize plants by spreading the pollen of one plant to another so the plants can reproduce. The most famous example of a pollinator is a bee but many insects serve as pollinators, for example butterflies and wasps.

A bee, covered in pollen. 

A bee, covered in pollen. 

A Monarch Butterfly

A Monarch Butterfly


(14) The Prey Layer (Animals That Eat Plants)

Many animals in a food forest eat plants. These animals move through the forest or jungle, which is something that animals have an ability to do to a much greater extent than plants can. Some plants take advantage of animal movement by producing a seed which can withstand the animal's digestive system. When the animal poops, that poop can contain seeds and can sprout new plants in new locations. 

The most ecologically significant role of the prey animals, though, is to act like moving biological super-composters. When animals eat plants, bacteria in their stomachs breaks down the food much faster than would be possible via the compost layer. Ruminants are one particular example of this. Ruminants such as sheep and goats have a four chamber stomach, which enables more complete composting of the plant matter during digestion through a fermentation process.

However, even prey animals with only one stomach chamber are able to compost organic materials very, very quickly when compared to composting rates on the ground in the compost layer. Grazers also serve the function of reducing plant size by eating leaves and fruit, which in turn minimizes overgrowth and allows light to penetrate the forest. The prey animals are kind of like the lawn mowers of the food forest, cutting down the size of plants and keeping them relatively tidy. Many prey animals move in herds for defensive purposes rather than as solitary individuals. 

Deer

Deer

Sheep

Sheep

Goat

Goat

Rabbit

Rabbit

As you can see from these pictures, the prey animals tend to be the cute ones! Because of the important composting and movement functions of animals, even a vegan planting a food forest would ideally include animals in the system design as well for the purposes of ecosystem health. 


(15) The Predator Layer (Animals That Eat Animals)

The primary purpose of the predator layer is to control the population of animals in the prey layer. If the prey animals were allowed to reproduce without the controlling function of predators, they would quickly overpopulate the area and start eating so many of the plants that the land would be damaged. This is known as overgrazing. 

Birds are an interesting example of predators who primarily hunt from the air. By eating insects from the pollination layer, they keep the bug population under control. Birds also have the interesting ability to access the upper branches in trees, which gives them an interesting biological niche in the forest. 

Some predators primarily eat other predators rather than prey animals. The last predator in the chain, the one who has few natural predators to defend against, is called an apex predator. There tend to be far fewer of these apex predators in terms of total numbers because so many more animals have to exist lower down on the food chain to sustain one apex predator. 

An alligator swimming in duckweed covered water. Alligators make a delicious meat source. 

An alligator swimming in duckweed covered water. Alligators make a delicious meat source. 

Grizzley Bears are an example of an Apex Predator. They are very dangerous to humans if the person doesn't have a weapon because they are significantly stronger and faster than people. Here the bears are engaging in dominance behaviors to learn who will have priority access to resources. Some predators are dangerous for humans to consume because they have a much higher disease risk than most prey animals.

Grizzley Bears are an example of an Apex Predator. They are very dangerous to humans if the person doesn't have a weapon because they are significantly stronger and faster than people. Here the bears are engaging in dominance behaviors to learn who will have priority access to resources. Some predators are dangerous for humans to consume because they have a much higher disease risk than most prey animals.

A Leopard, one of the larger cats. Cats are predators. 

A Leopard, one of the larger cats. Cats are predators. 

Many predators, like these wolves, hunt in packs. 

Many predators, like these wolves, hunt in packs. 

An Eagle is an example of an apex predator who hunts from the air. 

An Eagle is an example of an apex predator who hunts from the air. 


Conclusion: Synergy Between the Layers

The 15 layers of a food forest described in this article are:

(1) The Emergent Palms Layer
(2) The Canopy Layer
(3) The Sub-Canopy Layer
(4) Oversized Grasses
(5) Shrubs and Bushes
(6) The Herbacious Layer
(7) Runners
(8) Climbers
(9) The Compost Layer on the Ground
(10) Tubers and Root Crops
(11) Below Ground Fungus
(12) The Aquatic Layer
(13) The Pollination Layer (Insects)
(14) The Prey Layer (Animals That Eat Plants)
(15) The Predator Layer (Animals That Eat Animals)

What is the point of all this complexity? In a forest, each layer adds to both the diversity and the stability of the overall system. With so many interconnected parts, the overall system is still likely to function if one of the parts is temporarily removed. Applying this concept to our own task of growing food for ourselves, we can build in similar layers of complexity that give us both a wider variety of foods to eat and a more stable overall system. Because the optimal human diet is a diverse diet, the food forest concept has the potential to provide a wide variety of foods within a relatively small area.