Intro to Food Forests
Updated: Jan 12, 2021
Why would you want to grow a food forest? To grow lots of food of course! Imagine yourself, strolling through your yard picking apples and berries, collecting greens and veggies for your lunch salad, cutting a few flowers for the vase on your table and even picking some leaves for your evening tea to help calm you into sleep. Did I mention, all this and much less work as well? Welcome to your food forest!
What Exactly Is A Food Forest?
Food forests are exactly what they sound like: groups of trees, shrubs and under story plants all working together and producing food! The key here is the working together part. Just like forest systems that occur naturally around us, there are many elements that support and enhance each other. These include not only trees, but also shrubs, herbaceous plants, fungi, bacteria and protozoa all beneficially interacting with each other.
Think of the three sisters as an example; corn, squash and beans all growing together. The corn grows tall, giving the pole beans something to climb on. The beans are nitrogen fixers, increasing the nutrient value in the soil for the squash and corn. The squash has large leaves and dense growth, shading the roots of the corn and beans and suppressing weed growth. The squash also has prickly leaves and stems, helping to keep away browsing pests. Together, they grow even better than they do apart and all three of them provide food! The Aztecs successfully used this system of growing for hundreds of years.
You can apply these principles on a little bit larger scale in your Calgary garden. We observe the natural forests that exist around us, such as aspen parkland and montane forests, then mimic those same relationships at home. You combine species together that benefit each other such as trees, shrubs, fungi and herbaceous plants. These, in turn, benefit you with food or other materials. The result being a bountiful garden requiring far less work from us and fewer expensive resources, all while giving us yummy food. Win-win!
Many gardeners are new to the idea of food forests today, although they have actually been around for thousands of years. The oldest known food forest still in existence today is found in Morocco. Check out the story as described by Atlas Obscura here. There is a much younger food forest in Vietnam (a mere 300 years old) that has been passed down in one family for generations. Check out this great article about it here or a short video tour here. Food forests are not only possible, but very sustainable in the long term.
Convinced yet? Let's look at how to make it happen in your space!
Start With A Guild
A guild is a small group of species planted together to support a central element or to provide a service to us (such as food, fuel, crafting products, etc.) - kind of like a plant family. To create a food forest, we combine a number of these guilds together, similar to a neighbourhood full of families. To determine the suitability and placement of an element within a guild we consider a number of factors:
physical size and where it will fit
how it helps the main element
what it provides for us
if it serves more than one function
its life cycle
maintenance required by the gardener.
Let's look at each one of these in a bit more detail.
In order to reduce the area needed, we combine elements of different heights that have the majority of their biomass at different levels in space. This permits us to plant more closely together, while still allowing our 'babies' to grow to their fullest potential. We can group plants into seven different layers:
Tall canopy or medium trees (30 feet +)
Small trees (10-30 feet)
Shrub layer (4-15 feet)
Forbes/Herb layer (1-6 feet)
Ground cover (less than 1 foot)
Roots and tubers (most biomass underground)
Vines and climbing plants (most biomass on another element)
Depending on the size of your space, a tall canopy tree or even a medium size tree may not be possible. That is okay! Instead, we would use the small sized tree as our main element. Many people also consider fungi an additional layer, as most of its biomass exists in the soil layer. (Mushrooms being the "flowering" part of a large mass of mycellium intertwining throughout the soil particles.) Wetlands, including ponds or lakes and the species within them, may also be considered an additional layer. Keep in mind we need to consider the full grown size of plants - not the size they are at the time of planting. The point is for them to grow to their full potential! If we don't give them the space they need to do that we impede their development and risk opening up our garden to diseases and pests due to crowding. Always read your labels or do some research to determine the mature sizes of your plants.
We also want to shoot for perennial plants in our guilds. Obviously, this is not an issue for trees and and shrubs, but it needs consideration for forbes (herbaceous plants), ground covers, roots and tubers, and vining plants. Why perennials? One reason is they are less labour (plant once and forget it!) and less work for us is one of the reasons for making a food forest in the first place. The other reason we want to choose perennials is that we don't have to disturb the soil every year to plant new elements. Disturbing the soil (think tilling) will negatively affect its structure and all the life within it, such as insects, earthworms, fungi, bacteria and protozoa (all those microscopic guys).
I know you are thinking: aren't all of our vegetables annuals? Lots of them are yes, but there are many less common perennial vegetables that grow perfectly well here: sorrel, Good King Henry, lovage, Egyptian walking onions, rhubarb, chives, mitsuba, mint, horseradish, Jerusalem artichoke, salsify and the much loved dandelion. I use raised beds, separate from my food forest, for all my annual vegetables.
Plant placement Within a Guild
When considering an element's placement we need to take into account its specific needs. Does it like full sun or shade? Is it drought tolerant or does it prefer a moist environment? These preferences will determine where in the guild it will best thrive. Think about where the most sun will be (usually on the south facing side of the guild). Don't forget to take into account shade cast by the tall central element or from any nearby structures such as buildings and fences. Soil moisture is equally important. Is there swale nearby or a low spot that will naturally hold more moisture? This will be the place for guild plants that are naturally thirstier. Similar to placing plants in your garden, there will be areas within each guild that are best suited to each plant.
Within a food forest guild we want to shoot for multifunctional elements. Each element should do many things and many things should do each element. This tends to improve efficiency and and resiliency of the entire system. For example, comfrey is one extremely multifunctional plant often used in guilds. It is medicinal (a service for us), attracts pollinators, can be chopped and dropped to use as mulch, is a nutrient accumulator (potassium, calcium and magnesium), is also a weed suppressor, can be used as fodder for agricultural animals and is a stupendous addition to your compost. That is a lot of function out of one plant! We also want to plant a number of species serving the same function. For example, comfrey may be fantastic at attracting pollinators, but it is not in bloom for the entire growing season; therefore, we plant additional elements that also attract pollinators, but at times that comfrey isn't in bloom, such as haskap berries that bloom very early in spring. We can also add elements that attract different pollinators than comfrey does. If for some reason, our comfrey has a bad year, having additional pollinator attractants will help take up the slack. By having backup for each function, we cultivate resiliency.
Comfrey (Symphytum uplandicum) is one of the rockstars in the permaculture world. In addition to the attributes listed above, it is very fast growing and beautiful too. I suggest using the Bocking 14 or Bocking 4 varieties, as these do not self seed like crazy (it can get out of hand fast with standard varieties). If you want more plants, all varieties are easily propagated by root division.
Elements of a Guild
We talked briefly about a number of functions served by elements in our food forest guilds when we talked about our comfrey example, but let's take a look at all of the different functions individually. **Look for future articles that go into even more detail on each function and give you a comprehensive list of plants specifically for Calgary and area** Remember, when selecting our guild elements, we want each one to do multiple things and multiple elements to do each thing. Bonus points if each element is yummy too.
The Central Element
This is the big kahuna, the big cheese, the reason for our guild. It is the largest element and the one that is functionally supported by all the rest. Most often it is a large tree that provides food, such as an apple, pear or walnut. If we are creating a crafting guild, it may be a large tree that produces a desired craft material, such as a willow for creating bentwood furniture. When creating our guild, we choose this central element first based on our needs, then we choose all the other elements to help this specific one to thrive.
I have talked a lot about mulch in the other articles on this site (see Weeds and the Evils of Landscape Fabric for more info). But let me sum it up for you: it's awesome and you should always use it. So of course we want to add plants to our guild that can help in that department. There are a variety of plants that can be regularly cut down (partially or fully) and scattered around our plants to act as mulch. They break down and compost in place. We call this "chop and drop" in the permaculture world because that is exactly what you do. As you are strolling through your food forest, you chop down any mulch plants that are getting a little big, chop it into small pieces and just drop it right there on the soil surface. Mulch plants may also be ones that drop copious amounts of leaves, flowers, bark or branches (self pruning trees like aspen are one example) all by themselves. Even less work for us! Make sure that mulch pieces are no thicker than a pencil and are in contact with the soil surface. This will ensure they break down most efficiently.
Some examples of mulch plants are comfrey, rhubarb (a good way to use those leaves!), artichoke, nasturtium and ferns.
These are also known as living mulch plants and they act in some of the same ways as the mulch plants mentioned above. They reduce evaporation from the soil and keep plant roots cool in the summer and insulated in the winter, just like mulch. These guys are often ground covers. They grow thickly between the other plants and spread to cover any bare areas. This is good because bare areas are where weeds will grow. Weed suppressors can also be used as fortress plants that form a physical wall of growth to restrain more invasive plants. Some even have toxins that inhibit the growth of nearby plants, such as some Helianthus (perennial sunflower) species.
Examples of weed suppressors are allium, garlic, daffodils, strawberry, stonecrop, bugleweed, dwarf yarrow, thrift and clover.
Dynamic Nutrient Accumulators
Think of these guys as the fertilizers of our food forest. Many of them have deep tap roots. All the better to bring up nutrients and micro nutrients from deep down in the soil/subsoil. These nutrients are then concentrated in the leaves and root of these plants. When we chop and drop them in our food forest or add them to our compost (and later add that to our food forest) those nutrients become available to all the plants in our guild. Not only that, those deep tap roots are great for breaking up soil to allow for greater air/water absorption, especially in clay or compacted soils. You will notice that many of the dynamic nutrient accumulator plants are considered weeds. This is because they are often found in low nutrient soils, where only they can grow well by mining nutrients down deep where other plants cannot access them.
Some examples of dynamic nutrient accumulators are dandelion (accumulates phosphorous, potassium, calcium, magnesium, iron, copper, silicone), comfrey (accumulates nitrogen, potassium, calcium, magnesium, iron, silicone) and astilbe (accumulates phosphorous, calcium, sulfur, magnesium, iron).
Note that many plants that accumulate copper and zinc also accumulate lead. This can be used for remediation of contaminated soils if you dispose of the leaves and don't allow them to return to the garden system. If you have any reason to believe your soils may have lead contamination, get your soil tested before planting anything.
Like nutrient accumulators, nitrogen fixers also act as fertilizers in the food forest. Specific bacteria in the soil form nodules on the roots of nitrogen fixing plants and change nitrogen from the air into a usable form of nitrogen to plants. You can actually see these nitrogen storing nodules on the roots. You can make that nitrogen in the nodules available to all the other plants in your guild when you:
chop and drop! (mulch with cuttings of these plants or add to your compost)
cut back the plants (equal amounts of roots self prune underground every time you prune above ground)
do nothing! Nitrogen fixing plants will naturally release usable nitrogen into the soil around them all on their own.
Many of the nitrogen fixing plants belong to the bean and pea family. Examples include lentil, clover, lupine, comfrey, alfalfa, caragana, sea buckthorn, columbine, chamomile, chives and vetch. Similarly, there are plants that fix phosphorous, but they use fungi instead of bacteria. Poplar and willow are great examples of these.
Plants to Attract Beneficial Insects
We all know that we should be helping out our friends the pollinators whenever we can; without them we would have no fruit at all! It is always a great idea to plant flowers that bees, moths, butterflies and wasps enjoy so that they also pollinate our food plants. But pollinators aren't the only beneficial insects out there. The insect world helps us out in other ways as well. Did you almost forget about ladybugs? They are aphid eating machines (as are their larvae, by the way)! Other predatory insects that eat pests are tachnid flies, hoverflies and lacewings. Parasitic wasps help us out in a different way. They lay their eggs inside of caterpillars, and when the eggs hatch, the larvae eat the caterpillar from the inside out. It's like a horror movie but better, because it controls the caterpillars that eat our veggies! There are many plants that we can add to our food forest guild that are preferred food and shelter for these helpers.
Examples of plants that attract pollinators and predatory insects include echium (red feathers), salvia (perennial sage), asclepsis (milkweed), lavender, sunflower, stachys (lamb's ears), echinacea (coneflower), borage, bee balm, yarrow, clover, fennel, dill, coriander/cilantro, mint, hyssop, columbine and strawberry.
Plants to prevent Pests and Diseases (Repellents & Traps)
There are two different ways that plants can help us prevent pests and diseases in our food forest. This first way is repelling them. Plants can be extra smelly, have thorns or irritating hairs, or they can be poisonous. These qualities are useful in deterring damaging insects as well as fungal and mildew diseases. Any of these strategies may be used by plants typically recommended to repel rabbits and deer; used as a perimeter barrier they can be quite effective.
Examples of plants that repel pests include alliums, garlic, mint, oregano, lavender, marigold, salvia and horseradish (all smelly to pests) as well as gooseberry, sea buckthorn and Russian olive (all thorny), and daffodil or Aconitum (monkshood) (both poisonous).
The second way to prevent damage by pests and diseases is to have a trap crop. This is when you purposefully plant something that the pests really love. So they concentrate on those plants and leave the plants that are for you alone.
Examples of trap crop plants include dill, fennel, coriander and Jerusalem artichoke.
Wildlife Value Plants
In addition to guild plants that help out our central element or help out us, we can also choose guild members that are valuable to local wildlife. This can be plants that act as shelter, provide material for shelter, provide food or provide hiding spots away from predators. This can be anything from goldenrod (providing nesting material and winter food for birds) to Viburnum bushes (that provide hiding spots for birds and whose berries are often preferred over berries that people like better). Native plants are never a bad idea, as they have evolved along with local wildlife. See the article on attracting birds, bees and butterflies to the garden (coming soon) for a comprehensive list of plants and their specific uses.
Feed and forage plants
Our food forest can feed ourselves while feeding the other plants or wildlife, but we can also choose plants that feed our domestic furry friends. This can be anything from catnip for our cats to alfalfa and buckwheat for rabbits, chickens, goats, horses and cows. No matter the animal, there are food forest plants that can help to feed or shelter them.
These are elements that are temporary in our guild. They are planted initially to support the central element when it is just starting out. Nurse plants provide shelter from wind or strong sun to allow more fragile plants to get going. Often times they are nutrient accumulators and they are almost always fast growers that are short lived. Once the central element is established i.e. more fully grown and stronger, the nurse plant is removed to make space for additional guild plants. A prime example of this is fast growing poplars, used as a shelter belt, to protect more wind sensitive orchard trees.
Putting them all together
Phew! That's a lot of different functions that plants can provide in our gardens isn't it? I bet you already have a few of these plants now and never thought about what they are doing for you - besides looking beautiful that is. So far, we have chosen the central element for our guild. We have also selected all of the supporting elements, ensuring that we have covered all of the different functions listed above with multiple plants. We have considered where in the guild each will reside based on the specific needs of each plant (whether it prefers sun or shade). We have also thought about choosing elements for the seven layers so that we can get as many different functions and plants as we can into one small space. Remember, a guild isn't necessarily a perfect circle around your central element. Plants that are fertilizing in nature, should be located somewhere within the drip line of that central element in order to feed the roots. Things like barrier plants should be around the edges with trap crops even a little further away. Also, think about how many of each individual plant you want. For example, you will need a large number of daffodils if you are using them as a barrier plant against pests, because they are relatively small, and they will need to be grouped closely together to be effective. In general, the larger an individual plant within your guild, the fewer of them you need.
Guilds Into A Food Forest
Now it's time to turn that one guild into a food forest. A food forest is just an amalgamation of guilds. Depending on the size of space you have, you may have a single small guild consisting of a dwarf apple tree and six or eight different plants around it. Or you may have a collection of 10 or 12 guilds all with different central elements and different supporting species specific to that central element. Each of those guilds will also be positioned within your garden space so that the central element is in the best possible spot for it and the supporting species around it. Think about micro-climates, sun exposure, soil type and moisture (including access to supplemental water) when choosing where a guild should be placed within your landscape.
We also need to consider what to put between or around the edges of our guilds. You can always locate guilds right up against each other, but there are some situations where inter-guild elements are useful.
When you have a specimen that needs a buffer between it and other plants. A prime example is a walnut tree. They produce a chemical called juglone that inhibits the growth of many other plants. It would be a great idea to plant a juglone tolerant species between a walnut guild and any other guild, such as apple or plum.
For larger shrubs that do not fit easily under central element trees and are too low to the ground for other elements to be planted underneath them.
As a shelter belt to protect from extreme wind (which is very common here in Calgary) or intense sun to protect more shade loving guilds. This will be more common on the edge of the food forest.
To leave room for a pathway for travelling through the food forest and for harvesting.
Let's Go Through Some Examples
As you may have noticed, there is a significant amount of planning involved before we even begin to think about planting. The more time we spend on this, the better functioning our food forest will be. So take your time and do your research! Look for individual articles in the near future on each of the elements mentioned above with lots of examples that are appropriate for our Calgary climate. You can also check out any of the books and links in the references and further reading below.
Below is a guild that I designed for a large food forest just north of Calgary. It can have either an apple, plum or cherry plum tree as its central element and has a mixture of small shrubs and herbaceous perennials underneath. The large circle indicates the mature size of the central element with the small "+" as the center of the tree. Because the apple and plum trees specified for this guild are dwarf or semi-dwarf varieties, this guild is positioned in an area of the food forest with views to the mountains. The shorter elements don't block the fabulous scenery. This guild is also positioned in an area of the food forest with a swale running along the right hand side of it. Apple trees need a fair amount of moisture and the elements within the guild that need a bit more moisture are positioned on the swale side. In addition, the elements that need a lot of sun are positioned on the south side where they are not shaded by the tree or the shrubs. There is a mix of layers as well: the tree, shrubs, tall and short perennials, a few self seeding annuals, groundcovers and tubers.
In terms of functions, there are:
nitrogen fixers (caragana, false indigo, clover, columbine, comfrey, lupine)
dynamic accumulators (blue flax, comfrey, yarrow, dill, apple, clover, plum)
mulch plants (comfrey, caragana, bunchberry)
weed suppressors (bunchberry, clover, nasturtium, viola)
beneficial insect host plants (hyssop, clover, dill, penstemon, blue false indigo)
attractors for pollinators (apple, plum, salvia, columbine, echinacea, haskap, catmint, clover, comfrey, hyssop, yarrow)
to prevent pest and diseases (yarrow, dill, nasturtium, catmint, hyssop, walking onion, ginger)
products for people (apple, plum, cherry plum, currant, haskap, dill, hyssop for tea, viola and nasturtium for edible flowers, walking onion, wild ginger, echinacea for herbal medicine)
Notice each function has multiple plants to provide it, and each plant provides more than one function.
Below is another guild for the same food forest. We'll go into a little less detail this time, but the multi-functionality of all the elements remain the same. This one has an apricot tree as its central element. This guild is located in a very hot sunny area of the food forest, as required by the apricot tree. The other elements in this guild were chosen because they are also well suited for a very hot, dry and sunny location. Most of them are drought tolerant and many of them are good for cut flowers, as the home owner likes to collect flowers for arrangements. In general, the shorter plants are on the south side of the guild so that the plants on the north side are not shaded out.
Last one! This guild has a pear tree as its central element. Pear trees that grow well here tend to be pretty tall trees. Therefore, these guilds were positioned to ensure they don't block that fabulous mountain view. The height of the tree also allows taller plants to be positioned underneath it, so the shrubs can be larger than in the other guilds. As with the apple guild, there is a swale running along the right hand side so the plants that need a bit more moisture are positioned there and the more drought tolerant plants are positioned on the opposite side.
This food forest also has larger shrubs planted around these guilds with berries that are attractive to birds. The hope is that they will eat those and leave some of the berries that people like alone (or at least not completely ravaged). These included a number of Viburnums, highbush cranberry, dogwood, mountain ash, elderberry and buffaloberry. There is also a windbreak planted on north and west sides of the property consisting of spruce, pine, elderberry and Russian olive. Along the south and east sides of the food forest are lots of barrier plants. There are deer, rabbits, coyotes and a variety of rodents in this area. Barrier plants include the prickly Russian olive, caragana, gooseberry, rose, sea buckthorn and junipers. We also included a hedge of cotoneasters, as the deer seem to love eating the berries and seem content to not venture past them.
Now Take a Deep Breath
Did I completely overwhelm you? It will be okay if you take it step by step. The food forest I described above did not happen overnight. I began with a list of larger trees that grew the food we wanted to eat. Then I used books and databases to find plants that would support that tree and that liked the same growing conditions. I researched their mature sizes and used graph paper to fit them around my tree. Then I used the size of my completed guild to place it appropriately within the landscape (a real property report is a helpful tool for a scaled drawing of your property). It helps to know your property too. Find out where your hot dry areas are and where you have shade. Find your micro-climates. The better you know your property, the better you will be able to select plants that are perfectly suited to each part of it.
Keep in mind that there will be some adjustments along the way. Plants will take time to grow. Some plants may need protection from browsers until barriers fill in. Sometimes, you just can't find a certain plant or one just doesn't want to grow in your space. Or maybe your crazy sister brings you two dozen echinacea plants she started, and now you have echinacea in every single guild on your property. (I really just wanted to help out!) Be prepared to be a bit flexible and enjoy the process.
This design is slowly being planted. Because it is a pretty large food forest, it would be a lot of work, not to mention a a huge bill at the greenhouse, to do all at once! You don't have to do it all at once either. Slow and steady wins the race! Use those cold winter months to plan and dream about the food forest you could have in your yard.
Yummy gardening everyone!
References and Further Reading
The Permaculture Research Institute "Dynamic Accumulators Part 1" (www.permaculturenews.org/2015/05/12/qualifying-dynamic-accumulators-a-sub-group-of-the-hyperaccumulators/) and "Dynamic Accumulators Part 2" (https://www.permaculturenews.org/2020/05/18/dynamic-accumulators-part-two/)
Eagle Lake Nurseries plant database (http://search.eaglelakenurseries.com/11050003/) a database with Calgary and area specific plants, searchable by numerous features.
Plants For A Future (https://pfaf.org/user/Default.aspx) a database full of permaculture plants, searchable by climate, function, size and anything else you can think of.
Temperate Climate Permaculture "Nitrogen Fixers for Temperate Climates" (http://tcpermaculture.blogspot.com/2011/05/plants-nitrogen-fixers.html)
Hemenway, Toby "Gaia's Garden, A Guide To Home-scale Permaculture, 2nd Edition" 2009, Chelsea Green Publishing Company, Vermont, USA (this is probably my most used reference book for permaculture).
Mollison, Bill "Permaculture A Designer's Manual" 1988, Tagari Publications, Australia