On Roles, and Layers
If the reader has come across the idea of a food forest before, then the topic of layers should be familiar already, but for the sake of the uninitiated, I will attempt to describe the concept in brief. When setting out to design a permaculture garden, a food forest, or woodland garden (my preferred term) we want to mimic nature as much as possible, while designing in elements that best suit our own needs. What those needs are is entirely up to the designer .. Do you want a food producing system, or one that just looks beautiful? Do you want to grow building materials, fibers, medicines, or perhaps a little bit of everything? We will use the design of a natural forest as a template, and plug in species to fit.
Looking at the way nature grows a forest, we notice that the various elements can be categorized in layers. High above everything else is the Canopy Layer - this is composed of the tallest trees, usually the ones that take the longest to grow, and everything in this layer has the first opportunity to photosynthesize. Chances are, the choices that will make sense for all the layers below the canopy will be dependent on what you choose to put here. Next there are the Understory Tree layer and the Shrub Layer. Although these are two distinct layers, I put them together because with the exception of some true forest giants, the lower limbs of many Canopy Layer trees will occupy the space needed for the crowns of understory trees. Below the Shrub Layer is the Herbaceous Layer, occupied by plants that don't normally grow taller than a person - calf height to chest height is the normal range. Along the ground itself is the Groundcover Layer, and running vertically from ground to canopy is the Vining Layer. Finally, there is the Fungal Layer - and here there may be some outcry, because I have eliminated the so-called 'root layer'. I call the subterranean layer the Fungal Layer because the only species that derive their energy from below the ground are the fungi. Root vegetables like potatoes get their energy in the Herbaceous Layer, and sweet potatoes get their energy in either the Vining Layer or the Ground Cover Layer. If one is fortunate enough to live in a place where Cassava aka Yucca can be grown, you will notice that although the root is the edible portion, the plant itself occupies the Shrub Layer.
Ok, lets talk about roles for a bit. The first thing I want to think about when doing a design is what kind of yield am I looking for? Being more than a little obsessed with food security, my own personal choice for that primary focus is food, of course .. but even more importantly, the kind of food that i want to be able to harvest from the system .. and that is Staple Foods. Staples are those foods that provide calories or proteins, preferably both. If you happen to live in a climate where there are no good choices for staples, or the choices available don't appeal to you, then it is likely that in order to obtain them from the land will require animal fats or proteins .. in which case your first priority will be to find sources of food for those animals. Whatever your primary focus is, everything that is selected should be filling that role, or filling a role that supports that focus in some way.
After Staples, what else is a vital role that needs to be filled? How about fertility - Nitrogen, Potassium, and Phosphorous sources. In a purely plant-based system, the target should be for about 1/3 of all plants (or more) to provide these base nutrients back into the system. Look for nitrogen fixing Trees, shrubs, herbaceous plants and ground covers, and dynamic accumulators of potassium and phosphorous to grow and use for living mulch, or cut for compost. Some Superstars at accumulating nutrients include: Members of the genus Chenopodium (includes quinoa, lamb's quarters, good king henry, and others) These plants will accumulate Nitrogen, Potassium, Phosphorous, Calcium, and Manganese if those nutrients are present in the soil or sub soil. Most of them would occupy the Herbaceous Layer, and many of them are also edible by humans, or suitable as feed for some animals.
Members of the genus Rumex (including Docks and Sorrels) Do a fine job of accumulating Calcium, Phosphorous and Potassium, and several examples of those are also edible. The genus Stellaria (chickweed, various species) occupies the Groundcover Layer, and accumulates Phosphorous, Potassium, and Manganese. Chickweed is yet another edible plant in this category. There are many other dynamic accumulators that, although they may not be MVPs at least deserve a mention: Comfrey is noted for its ability to accumulate Nitrogen, Potassium, Calcium, Magnesium, and Iron, Borage is an excellent miner for Potassium, is also edible with leaves that taste like cucumbers, and Amaranthus deserves a mention for accumulating Phosphorous, produces profuse amounts of seed that are edible as they are, can be popped like popcorn, used in soups, or sprouted for microgreens.
There are a few additional notes regarding dynamic accumulators. First, reflect on the principle of balance; if there is something that is going to leave the site as an export, make sure that you are providing a means of putting it back into the system. Garlic might be an excellent 'cash' crop to export, but it is going to use a lot of Nitrogen and Sulfur. Consider planting mulberry trees to accumulate Sulfur from the subsoil, and use the leaves to mulch the garlic beds. Second, do not confuse the term 'accumulation' with 'production'. IF a plant is a hyperaccumulator of a particular nutrient - Nitrogen, for example, but is not ALSO a nitrogen fixing plant, it should be planted in combination with a nitrogen fixer, or with some other source of nitrates .. manure, for example. Third, if a nutrient is not available in the soil or subsoil, it doesn't matter how adept a plant is at accumulating - see note number two. Soil Ph plays a role in the availability of nutrients, with the 'sweet spot' for soil Ph being between 6.5 and 7. Consider Calcium accumulating plants to produce mulch that will tend to raise Ph, and Sulfur accumulating plants to Lower Ph. Finally, the plants that I have mentioned previously should not be considered to be a 'list' of dynamic accumulators - they are merely a few examples. At some point, I will compile an expanded list of potential accumulators, but even that will not be anywhere close to what I would consider a complete list. Next, lets look at pest control roles. Take a gander at these four pictures below:
My grandfather died of cancer in 1973, the year that I turned two years old. Now I've mentioned before that grandpa was involved in the permaculture movement early on, well before the movement got started, really - but he was a vegetable farmer, and like everyone else at the time, that meant riding around on the tractor, spraying chemicals. A man dying of lung cancer at the age of 74 might not sound so significant, but Carol Conrad was a member of a family noted for their longevity, and he never smoked - could the pesticides that he inhaled day after day while working the farm have contributed to his demise? We think so. I don't relish the idea of dying of cancer at a young age, and perhaps you share that sentiment .. so here are some ways to use nature to deal with pests.
Role: Wildlife attractor: In the photos above, you will notice a flower, perhaps an allium, though I'm not entirely sure .. what I am sure of are the ants tending to the aphids gathered around the stem bear the flower. The aphids are sucking out the fluids from the plant's tissues, and secreting a substance called 'honeydew', that the ants love. The ants protect the aphids from harm (mostly) and in effect, are 'milking' the aphids, just like dairy farmers milk their cows. In the second photograph, we can see some kind of oblong, golden yellow to slightly orangish eggs clinging to a leaf in a cluster .. what manner of insect do you suppose hatches out of these? In the third photo we see some horrific looking monster of an insect, and in photograph number 4, we see that same insect, metamorphized into its pupate form. Bugs, eww .. they're just icky, right?
Here's a fun factoid: Not all aphids are green - some are black, and the black ones emerge earlier on in the season. They are attracted to plants like Urtica Dioica .. the Stinging Nettle. Stinging Nettles, incidentally, are great accumulators of Potassium, Calcium, and Magnesium, and are right up there with mulberry when it comes to accumulating Sulfur. They are rich in vitamin C as well .. if those sorts of things are important to you. Now if you aren't spraying pesticides, and you have stinging nettles, those black aphids are likely to come along and start snacking .. and that is going to attract the predator species that LOVES to munch on aphids every bit as much as the ants love to milk them. We just saw pictures of its eggs, larva, and pupate forms .. what is it? Our friend the ladybug! (There is a good chance that the larva and pupa in the photos is of the Asian or Harlequin variety of ladybird beetles .. If you are watching the video, I will take a minute to tell you how to tell the difference between harlequins, and their less obnoxious cousins) OK. By feeding the ladybugs early on in the season, we have the chance to get their numbers up by the time those green aphids emerge .. and a single ladybug can gobble down 50 aphids a day. Game. Set. Match. Here's a picture of stinging nettle, complete with a hard working pest destroyer.
Of course there are many plants that attract wildlife, and I could spend a few hours talking about them .. but for now, lets move on to another Role: Insect Repellant! Strongly aromatic plants can confuse pest insects, making it difficult for them to home in on the pheromonic scent of their favorite meal .. Marigolds are a fairly popular garden companion, as is Basil. Two of my personal favorites are Peppermint and Lavender (Coming soon to an online nursery near you, $3.99 each, 4/$15, or 8/$25 plus shipping and handling, these plants are shipped in biodegradable recycled cardboard pots, just tear the cardboard off and use it for mulch when you plug that little herb into your garden. Quick, convenient, and environmentally friendly) *cough* Aside from being absolutely essential for making a proper Mojito, Peppermint is good for deterring the vine borer moth, and Lavender has a scent molecule that binds with the scent receptors of mosquitos .. reducing their ability to locate YOU.
While I have mosquitos on my mind, here are a few more tidbits on the obnoxious little pests .. first off, did you know that they aren't pests at all? The mosquito's primary diet is nectar, particularly nectar from evening and night blooming flowers, some of which might never be pollinated at all if not for those adorable little critters. When you wear perfumes that smell of flowers, and wear bright colors, you are advertising to the mosquitos "Here is a flower, come drink me" The females alone drink blood, and then only enough to get the protein she needs to form her eggs. Plant Lavender along your walkways so that it brushes against you and your guests as they walk by, wear darker colors and avoid floral scents, and poor mother mosquito just might have a hard time making a meal out of you.
Talking about mosquitos and their habits brings another plant to mind, and another Role: Insecticide! Sometimes it becomes necessary to bring out the big guns when dealing with pests, and the next perennial I have in mind is so effective as an insecticide, genetic engineers have spent millions of dollars and a great number of years figuring out how to modify crops to contain its active ingredient. The plant in question is Nicotina Sylvestris, the woodland tobacco - a night blooming tobacco, which, if planted AWAY from areas where people are likely to gather in the evenings, just might lure the mosquitos with its heavenly scent. This plant contains nicotine, although not at the concentration of commercial tobaccos, but in high enough concentrations that an infusion of the leaves can be sprayed as a spot treatment for problem pests - but please be careful, it is lethal to beneficial insects as well.
Nicotina Sylvestris is a perennial, USDA hardiness zones 6-9, UK cold hardy to zone 7. We do not have any growing at the time of the live broadcast that is set to air along with this blog post, but we DO have plans to add it to the nursery lineup in the future, pending some research that I have to do with the legal mumbo jumbo. As a flowering ornamental plant, there should be few if any restrictions in the continental United States, although I am aware that there are several countries where the sale of this plant is prohibited. Those same countries permit foxglove, which is just lethal, and morning glory and rhododendrons, both of which have hallucinogenic properties. Do we have time for a talk about Grayanotoxin poisoning, "Mad Honey", and the military misadventures of Rome during the career of Pompey? Maybe someday. Let's move on for now.
Speaking of honey and bees, and plants with some medicinal value brings to mind an example that fills two Roles: Pollinator Attractant and Medicine (Antiseptic). The plant in question can be seen in the photograph above, and it is of the genus Monarda. The one in the picture is a bergamot beebalm, so called because it has a scent that closely resembles the aromatic oil used to impart that special flavor to Earl Gray tea. All Monardas have potent scents that draw pollinators in like mad, and although there are variations to the specific scent or flavor, they all have a high concentration of a chemical compound called Thymol.
Thymol can also be found in Thyme (no surprise, there!) and is VERY concentrated in Oregano (did I mention that we are growing Greek Oregano in the nursery as well?) Indeed, the potency of fresh oregano, and of the essential oil is such that it can not only stop the pain of a toothache, but the antiseptic properties make short work of the bacterial infection that were causing the pain in the first place. Thymol is one of the four active ingredients in the popular antiseptic mouthwash Listerine .. the others are Menthol (derived from mint) Methyl Salicylate (oil of wintergreen) and Eucalyptol, which comes from .. you guessed it, Eucalyptus. We should have at least one variety of Monarda available by next year, and wintergreen will be added to the store some time after that - we are currently building our own supply up. Essential oils of Lavender, Oregano, Peppermint, and Wintergreen will be available at a future date, if not from Green Country Agroforestry, then from our affiliate company, Happy Bear Farms.
Do we have time for one more? OK, one last tree, this one with several Roles: Biomass, and Nitrogen Fixer. A Biomass plant is one that grows quickly, and provides a source of carbon for making compost .. this one has an additional benefit in that it has a special relationship with soil bacteria that enable it to capture nitrogen from the air, and make that nitrogen available in the formed of nitrate nodes at the root level. If you look at the photograph above, you will see it .. this is an Alnus Glutinosa, or Black Alder, also called European Alder. I love this tree for a number of reasons, although it is listed as invasive in Maryland, and outlawed by the state of Wisconsin.
As a fast growing biomass producer, Alders are fantastic - and their wood is suitable for growing mushrooms that like medium hardwoods - Turkeytails, Reishi, and Amadou (that's the three mushroom anti-cancer medicinal blend, by the way) Shitakes, Enokitakes, Oysters, Winecaps, and more. Those seed cones that you can see in the picture are a natural but gentle means of lowering Ph, and as such, they are highly prized for aquarium enthusiasts. A powder made from the inner bark, combined with oil of wintergreen and perhaps a low abrasive like sodium bicarbonate makes a great toothpaste - We will have that available through Happy Bear at some point in the future. Alders are one of those trees that have the capability of forming mycorrhizal connections with both arbuscular and ectomycorrhiza, and as such are an important part of any forestry management system. Look for Black or Red Alder to be available in the nursery within a few years.
OK, I think that I've gone on for long enough .. there are plenty of other examples, and probably a few more 'Roles' that various plants play in the design of a permaculture system, but hopefully these few that we mentioned today will give you some inspiration to start thinking about what you could be growing in your own woodland garden.