The following is a write-up of a seminar in Toronto on April, 1st, 2010.
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I am going to give you an outline of what permaculture is, how permaculture design is done and how it can be applied to urban environments. In order to explain the design process, I am going to be mentioning a number of things that might appear to have no relevance to the urban situation. I do this to explain the principles of permaculture design and hopefully give you a core understanding of how and why I make the suggestions I do.
Before I start jumping into things, I think it’s important to give some definitions. First and most importantly is defining permaculture. The name permaculture was coined by combining permanent and agriculture and permanent and culture. Sustainability was not a buzz word back in the 70s when permaculture was developed. Simply put, permaculture is system for designing sustainable human environments. That means meeting people’s needs for food, water, shelter, energy, waste control and less tangible needs such as community structure and services. It’s also environmentally specific, so the systems I have designed on my land are different from the ones I have designed in semi-arid India, temperate Japan or temperate and sub-tropical Australia or the proposals for a project in tropical Uganda later this year.
This definition of permaculture requires another definition and that is the meaning of sustainable. The word has very seldom been given a clear definition and, as a result, has increasingly been co-opted as a marketing term. Looking to see how the word is misused, I discovered a few years back that a large and infamous agro-chemical company was selling its glyphosate herbicide as a way of “creating sustainable pastures.”
Here’s the thing about their product:
It’s toxic to amphibians.
It kills Rhizobium bacteria, which are the bacteria living symbiotically with legumes that are responsible for fixing atmospheric nitrogen. So, if you plant GM soy in the hopes of boosting soil nitrogen and cutting weeds with the glyphosate, you are unknowingly reducing the nitrogen-fixing capacity of the soy.
It kills mycorrhizal fungi, which are important for soil health. Mycorrhizal fungi help plants attain vital minerals like calcium, phosphorus and magnesium. They help supply water to plants in drought periods. They allow different plants of different species connect together to exchange nutrients and help fight disease and pest attack. Killing them off is very detrimental to soil fertility.
It is claimed by advocates of the chemical that it cannot leach into water systems because it bonds with soil particles. It does, however get into water systems and, when it does, it is toxic to fish.
While not directly toxic to birds, the ecosystem as a whole is affected, reducing local bird populations. This isn’t speculation, this has been observed.
In humans, it has been found to cause non-Hodgkin’s lymphoma.
Clearly, it is not “sustainable” if the word “sustainable” is to have any real meaning. And without a clear definition, the only time we will ever truly know the answer to whether something is sustainable or not is when it isn’t sustainable.
Here’s the definition: A system is sustainable if over its lifetime it produces or stores more energy than it consumers in its creation, operation and maintenance. Think of a bank account as an analogy. How long can you continue your lifestyle if you are continually spending more money than you earn? Sooner or later, that lifestyle will come to an end.
If you run your civilisation this way – spending energy than you store – it will most definitely collapse eventually. The example in this slide is Rapa Nui, but there have been numerous other examples throughout history. Were Easter Island in its original state, it would be covered by subtropical forests.
I would like to point out a little snag with this definition, however. Consider the embodied energy in an artist’s canvas. Finding figures for embodied energy is difficult, but let us say for the of argument that the embodied energy in the canvas – the energy involved in growing the hemp, processing it, weaving it, and its transportation costs, energy costs in the wood, in the metal staples holding the splined canvas together, the energy in the paint, and the energy costs of the artist painting a picture comes out to the equivalent of 10 litres of gasoline. Is the Mona Lisa worth just 10 litres of gasoline? How about 100 litres? Could you imagine any situation where you might trade the Mona Lisa for 100 litres of petrol? For 10 litres? Perhaps.
As you might imagine, accounting for the energy costs of something like a home or a dam could become very complex. What if it is a great design that requires virgin forest to be cleared to create it? What if it will wipe out the habitat of an endangered species? I think there is a way out of this problem.
Consider as an analogy the example of the Greek Korous purchased by the Getty Museum when the directors there wanted to establish it as a world-class museum. All the scientific tests said the remarkably intact korous was genuine. Yet immediately upon seeing the piece, experts proclaimed it a fake and advised the Getty not to purchase it. Stating exactly why it was a fake was difficult. It seems little things like incorrect hand size were registering on the unconscious mind of the experts, but they spotted the fake nonetheless.
I believe that with a little practice, we can all do with sustainability what the art experts did with the korous, if we keep a conservation mindset and apply rigorous honesty.
Now, I’d like to spend just a few minutes on what’s happening in the world and where we are going. I am sure everyone is well aware of where our climate is headed and the accompanying acidification and pollution that go along with it. The climate is an incredibly complex thing and exact prediction is very difficult. One thing to realise is that scientists are, on the whole, very careful about what they say and certainly about what they predict. As such, IPCC predictions sound somewhat manageable. These predictions, however, do not take into account knock-on effects like methane releases from arctic thawing, methane being 22 times as potent a greenhouse gas as carbon dioxide. This would lead to a feedback of increased warming causing more melting of ice, meaning less albedo, in turn meaning more warming, meaning plant die-off, meaning more carbon dioxide being released, meaning more warming, meaning ocean die off, meaning more CO₂ released, meaning more warming, and along the way, more erratic weather meaning more crop failures.
In the unlikely event that climate change should turn out to be no big deal, we nevertheless face an extremely serious problem due to soil erosion and degradation. Soil erosion is off most people’s radar because it is not a very sexy threat. Roland Emmerich has not and will not make a movie about the world going to pot because of top soil washing away. Yet, not single civilisation that has collapsed has not had loss of soil as a major contributing factor in their collapse. The difference between soil loss today and historical losses that have led to collapse is that we are now doing in the space of a few years what used to take many centuries to achieve. Pivot irrigation in arid and semi-arid regions can make land unusable in just 3 years time, after which they just more on to a new patch of land. This is one of the costs of the technological advancement of the mechanization of agriculture.
Hand-in-hand with soil loss is deforestation. One of the things that forests do is build and maintain fertile soils. For reasons that I don’t have time to go into, they might also be thought of as rain makers.
Pollution, which is really an issue of either unused excess resources or using the kind of resources that degrade other resources, is also a major issue. Climate change is one example of this, but there are other issues such as long term damage of soil and aquatic systems from persistent pollutants such as dioxins. Damage from environmental estrogens is another issue; and even more serious is the death toll in the millions worldwide from air pollution – particulate matter (deaths mainly from cardiovascular disease and lung diseases).
Now this sounds really horrible, and while it is, there is reason to take heart. Nature is very resilient. It takes tremendous effort and a fair bit of time on the whole to damage it. But it you pattern your actions in harmony with nature, the response is immediate and positive.
I could mention the decline of fossil fuels. While this does present a challenge considering that we have designed our food systems to be totally reliant on fossil fuels, it is ultimately more of a solution than a problem. Yes, right now we rely on natural gas to synthesize nitrogenous fertilisers; and we rely on diesel and gasoline to produce and transport that food, and to some extent we rely on the energy from coal to process that food. But there is nothing I can think of that would be more disastrous to human civilisation than the discovery of some inexpensive, plentiful replacement for fossil fuels, be it renewable or not. The issue is the overabundance of energy, not its non-renewability, which will become apparent in a few minutes when we look at design. Look at the damage we have already caused due to easy access to energy. Having a fresh supply in a new form is not going to end this destruction.
For a mega city like Toronto, this leaves a significant challenge. In terms of primary production, cities consume and contribute next to nothing. In some cases, like Tokyo where I lived for over a decade, there is simply no future. The nation of Japan did have a sustainable population at 30 million people but they now have that many in an area a little larger than the size of Algonquin Park. Quite simply, that is a temporary arrangement. They can have a go at growing on every rooftop and balcony in the city, but in the end, the population density is too high to support sustainably. Already the majority of the calories the Japanese consume come from imports and the percentage of calories from food actually produced from within Tokyo itself is negligible.
Toronto has enough unused land within the city to meet a large proportion of its needs. Not all this land is immediately usable, mind you. Lead contamination, for example, is a serious problem in many areas of the city and all soil needs to be tested before being used. Rehabilitation is possible, however.
Meeting energy requirements for heating is another challenge; and, due to Toronto’s odd layout, this will be difficult. More on this later.
There are three approaches that we open to take:
The first is to do nothing. Continue to operate with the energy-intensive regime to meet our material and immaterial needs. But with 10 calories on average being spent to produce one calorie of food, this regime will come to an end sooner or later.
The second approach is a return to labour-intensive traditional approaches. Some approaches were more laborious than others. Rice growing, for instance, is nearly nonstop work when done the traditional way. Other approaches to meeting needs were not always that bad, but still pretty hard work for what usually amounted to a nutritionally meagre diet.
The third approach is the design-intensive approach. Whereas the first relies on letting machinery carry out the brute work, energy in other words; and the second involved using human and animal labour to meet human needs, the design-intensive approach is knowledge and creativity intensive.
Permaculture is a design intensive approach. And different from other systems of design, it is guided by an ethical code, namely
- Care of the Earth
- Care of its people
- And return of the surplus to meet the needs of the Earth and the people.
We may be trying to become sustainable, but even following the ethics, I feel there is a serious piece of the puzzle missing.
What are we trying to do here? This is a serious question. In fact, it is the most serious question one can ask. I believe that we face all the problems I mentioned earlier because we are stumbling along, half-conscious without a real understanding of what it is we are doing. Just what is the goal of our society, or of the global society as a whole?
Is the goal long term survivability, otherwise known as sustainability? Not by any stretch of the imagination. We are living well beyond our means with the dream that some wondrous technology will come and solve this problem for us. There is no better recipe for collapse of civilization than that. Looking empirically, if survivability is our goal, we as a species are either grossly incompetent or incredibly stupid.
Is the aim of our society personal or community happiness? Again, no. We have data consistently showing that while personal wealth has, on the whole, increased, happiness has decreased. As Lord Turner, former head of the Confederation of British Industry recently pointed out, “All the evidence shows that beyond the sort of standard of living which Britain has now achieved, extra growth does not automatically translate into human welfare and happiness.” Communities, too, are becoming less integrated and interdependent than they once were. This is not a good outcome for a tribal species.
Is the aim to maximize human potential? No. The concern of our society is not to get as many people as possible to experience the maximum personal growth possible. National funding on mental health and education are enough to indicate that this is not a serious aim.
Is the aim simply to meet material needs for clean, healthy food, clean water, clean air, shelter and energy for warmth and cooking? The food we eat holds less nutritional value now that we’ve industrialized food production. Furthermore, biocide use contaminates not only the food, but more importantly and more severely the farmers and environment that produced it. There is no clean air unpolluted by man-made chemicals anywhere on Earth. There is no clean, uncontaminated water left, save for what is available in glaciers. Shelter is available, to some at least. Looking at homeless populations, it appears that shelter is available, provided you are both mentally fit and gainfully employed or with sufficient financial reserves to provide you with a roof over your head. And energy to stay warm and cook food? The same conditions seem to apply as for shelter. So, no, this is not the aim of the current system. If it were a serious concern, it would meet these needs better, assuming again that we are not all outlandishly incompetent.
Looking at the outcomes, it appears as though the aim of the current system is to accrue and secure financial power to those clever enough, educated enough, lucky enough and/or devious enough to get it and hold on to it. Again, I base this on observation, not ideology. I am not making an argument for or against markets here, I am only looking at outcomes. I know of situations where markets work brilliantly and others where they fail miserably. I am only interested in reality, not ideology, because reality always gets the last punch.
So now that we consciously know what it is we are actually doing on the whole – not trying to be happy, not trying to improve ourselves, not trying to be healthy, not trying to survive as a species, but rather trying to have power over others – we can ask if we want to do this or do something different.
I can’t stress enough how important this is. I can list a whole bunch of tricks and techniques to capture energy or produce food; but without having a coherent goal, it’s not going to change much of anything.
I mentioned at the start that permaculture is about meeting human needs, both tangible and intangible. Looking at this slide which I have based heavily on Maslow’s hierarchy of needs, we can go through point by point and ask how well the status quo system is doing at meeting those needs. Some are met, others are not. Almost none are met sustainably, which is where permaculture comes in.
Let’s now look at the design process.
The kernel of sustainable design is designing action around energy, not energy around action. Most action today is planned and executed with the energy it requires being just an afterthought. A person builds a new house, for instance, and then figures on heating it after they have settled on a design. The usual option is a gas furnace thrown in to keep things warm in the winter and an air conditioning system to keep the home cool in the summer. Energy is an afterthought here. The source of that energy is almost never considered.
Contrast that with my home. It has a passive solar design – windows facing the sun to let the 957 Watt hours per m² available to us from sunlight into our home where it is stored in the concrete floor to slowly radiate into the home throughout the day. A masonry stove is the backup heat source. This very efficient stove channels the hot flue gases though a large brick mass that stores the heat and lets it out slowly. The windows are designed to allow heat to escape in summer. There is no air conditioning; and after over ten years in stifling Tokyo and working in 45°C+ heat on a permaculture project in India last year, I really can’t imagine me needing air conditioning. This is Canada after all.
Another strategy permaculture uses to apply this approach of designing action around available energy is in the creation of zones of activity. It is basically placing elements of the system that are frequently used closer to the home (or centre of activity) and ones less frequently used farther away. As straightforward as this sounds, it is not often applied. Nearly every single garden I have seen in Canada is placed not only far from the kitchen where the food it produces will be used, but in the farthest end of the yard as though a garden is some undesirable thing that you want as far away from you as possible.
On a given site, there are a number of resources and energies that flow through the site that are available to us until they ultimately are lost off site. They arrive to us from a source and are lost to us in a sink.
We want to slow down the path of these resources from the source to the sink, making them available to us for as long as possible.
As one example, here is a system in Australia I helped consult on with a company there called Permaculture Solutions:
In this case, not only is the flow of water slowed as it moves from the top of the system to the bottom, nutrient flow is slowed as well. The fertility from the animals flows from the top, helps to fertilize trees, and helps grow reeds at the bottom of the site which are then cut and physically transported to the top of the site.
We can look at this as assigning each element in the system multiple duties. This builds redundancy into the system, making it more resilient. For nonliving systems, it conserves resources to assign multiple duties to each element. For example, the more duties we give water, the more effectively we can use water. (Don’t include grease filters in your greywater systems.)
Elements in the system do not act in isolation, they are linked together. The goal is to make the total system as self-regulating as possible. This will save human or mechanical labour.
In the chicken-heated greenhouse, chickens are given shelter and heat from the greenhouse and nutrients from the plants. The plants supplement the chickens’ diet and are fed by the chicken manure. The greenhouse provides both of them with water with its water catchment system. Putting complimentary systems together saves energy.
Now, you will notice in these examples that what might otherwise be considered a waste product is cycled into another process. What would happen, though, if the product from one process went unused? Well, then it would be a form of pollution. A cattle farm on a holistic management system can produce high quality meat, improve pastures and be carbon neutral or even sequester carbon. But what of the case of shed-raised animals? Industrially produced feed, usually in the form of grains, which is not part of the natural diet of cattle, makes them farty, meaning more methane produced. The dung then collects, releasing both carbon and nitrogen into the air, contributing to a global climate problem and a local stench problem. It can also contaminate water systems, putting lives at risk. The problem here is an excellent resource, cattle manure, is in excess supply. This gives us a definition: pollution, then, is the situation in which an unused resource is in excess supply.
We have this problem now with energy, as I alluded to earlier. Supply a system with too little energy and it will struggle and possibly die. Supply it with too much and chaos will ensue. Industrial production systems have too much energy and are thus leading to demented results. I also assert that the same holds true for monetary wealth. It may be a little bit of a philosophical journey, but consider what happens to the individual who suffers from wealth pollution.
Heating
Now that we have an understanding of what permaculture is and how the design process works, let’s look at addressing some specific problems, starting with heating. In a cold climate, up to 20% of the economy can be devoted to keeping warm. Conservation is the first issue to address.
For home owners, a home energy audit is a good place to start. The Ontario Ministry of Energy and Infrastructure will help pay for an energy audit. If you get one and follow the recommendations and can demonstrate that you lowered your energy consumption, the Ontario government will reimburse you up to $150 towards the cost of the audit. The Ministry’s website explains the program and how you can receive up to $10,000 in rebates for improvements to energy efficiency (perhaps unavailable now after the recent announcement from the fed). The improvements boil down to bringing insulation up to par, fixing drafts and putting in a more efficient heat source, that kind of thing. But there are other approaches to take that are effective as well.
All my life I have been cursed with energy efficient homes. During my wife’s first winter in Canada, we rented an insulated cottage in Muskoka. With temperatures dropping down to -27°C, the insulation didn’t really suffice. One problem was, and I am not making this up, the homemade double pane windows it had, not to mention the glass-on-glass sliding windows. I knew it would be well worth it to create window plugs the help hold the heat in during the day. These were simply 1-inch sheets of Styrofoam cut to fit the window sill and surrounded with foam weather stripping tape to make a good seal. Good windows, such as the ones pictured only have an R-value of around R-4. Putting the plugs in moves you to about R-8 or 9, and if you use the denser R-10 foam, you would get closer to around R-12. I would put them at sunset each day and I knew they worked because when I took them out in the morning, the inside pane of glass would always be covered in frost – something that would not happen without the plugs. This was a temporary set up, but I will be using a decorated version of the same thing in the home I am currently building.
If these plugs are not suitable, you can make windows a little more efficient with floor-length drapes. A fablic “sausage can be placed on either side of the drapes and a piece of cardboard over the top of the rail to fill in the space between the drapes and the wall. Better still is a piece of foam rubber. It works best if the curtains are sealed to the wall at the sides – either tacked or velcroed.
A crash course in passive solar retrofitting
There are 3 types of heat available to us for heating: Convective Heat; Conductive Heat, and Radiant Heat.
Conductive heat is the sort of heat that comes from a hair drier or a forced-air furnace. It feels nice but is the least efficient way to heat. Conductive heat is the kind of heat that one gets from direct contact with a hot object, such as a fry pan or sitting right against a masonry stove. This is the most efficient form of heating but it is not always too practical. Radiant heat is the sort of heat that you feel coming from a fire or warm object at a distance. It is radiant heat that we utilise in passive solar design.
As I mentioned earlier, on a clear day, there are 957 Watt hours per m² available from the sun at 45º latitiude Since this amount of heat is so significant and is free, we should take full advantage of it. Passive solar works by allowing light into a building where it heats up objects inside.
To make passive solar effective, one needs a large, dense mass to store the heat and slowly radiate that heat out. Otherwise the heating effect only lasts while the sun is directly shining into the home. This is usually done by either having the home built on an insulated concrete pad or having a brick wall inside the home. If you don’t have either of those, such as is usually the case for people living in apartments or condos, you can build a variation of the trombe wall.
A trombe wall is simple a dense wall (usually concrete or brick) with a window over it. I realise that it is not very likely that people are going to go home and build a brick wall over their windows. Consider this retrofit instead:
If you build a frame to hold stacked bottles, the bottles can be filled with water, which will act as a thermal mass to hold the heat. As dark colours heat up better, purple wine bottles work well, plus you get to drink a lot of wine to make the wall.
Another approach is a thermal siphon. There are companies that make these ready to install, though I recall that they are a little pricey. I know someone who has one and they work very well while the sun is striking them.
If you are comfortable building yourself, you could make a thermal siphon rather cheaply. If you built it like a box, it would be installed on a roof and have a fan to force air through it. There is a product in Australia that is a version of this called the Sun Lizard.
Now here I should mention a real problem facing Toronto. This image shows with greatest challenge for passive solar retrofitting: dense housing on streets laid out north to south. For the life of me, I cannot understand why the city founders chose to design their city to minimise solar gain as one would in a desert community, but they did. Needless to say, this makes design very difficult.
The use of reflectors can maximise the amount to solar gain by harvesting sunlight that would otherwise be lost. Using stainless steel, mirror or Mylar, sunlight can be directed into either an east or west window and, if the architecture allows, a north window. The gain is significant enough that it is well worth it to take advantage of if possible.
Here is an example of a system I designed for a west-end home. It was the north-end of a duplex and the only scrap of sunlight I had to work with was off of the northeast corner facing the backyard. There was a grape trellis already, so the reflector could easily be mounted on it.
Energy
If you are a home owner and your site is suitable, you can take advantage of Ontario’s Green Energy Act. With it, the Ontario government will give you a 20-year contract to buy power you generate, with the best price paid being 80.2 cents per kWh, which is for solar power. Switch is a third party non-profit that will consult with those interested in taking advantage of this program. Their site is www.switchontario.ca.
As I mentioned earlier, the end of fossil fuels is in sight. A permaculture classmate of mine in Australia, Darren Doherty, thinks we are headed for a charcoal economy. This may be the case, though we would not be able to and should not consume energy at the rate we currently do. Biomass through coppice crop is a possibility, but if it is done in an industrial way, it is would just be yet another harmful activity. The Swedes have coppice cants of willow that they use to mop up excess nitrogen in sewage treatment plants and harvest them with modified combines. While it is a step in the right direction, it has its problems.
Green roofs and green walls are all the rage. They are very effective at reducing rooftop temperatures in summer and contribute to insulation, helping to reduce heating costs in winter. Aesthetically, I find them much nicer than looking at concrete. The federal government used to have a very good incentive program to encourage the retrofitting buildings, but I am not sure if this program is still in effect. As far as green walls go, there are numerous approaches one can take as you see here. It’s also possible to build a trellis and send climbing vines across them.
Food
If you are going to be doing any gardening other than growing in containers with potting soil, you should have the soil tested first as heavy metal contamination can be a serious problem in some parts of the city. Here are some labs that can do testing:
A&L Canada Laboratories http://www.alcanada.com/
Agri-Food Laboratories http://www.agtest.com/
Soil and Nutrient Laboratory and the UoG http://www.uoguelph.ca/labserv/units/soil-nutrient/
Tests will be in the neighbourhood of $10 to $20.
When it comes to gardening, the first step is assessing the site. As I already mentioned, sunlight is a problem in Toronto and it is the first thing to consider. If you get 6 or more hours of sun, you can grow plants requiring “full sun.” If you get a minimum of 3 hours sun, you have “partial sun.” Remember that reflectors can help to increase access to sunlight and can be used in a garden.
The next difficulty to consider is wind. This can be a real problem for people growing on balconies or on rooftops. If may be necessary to provide a windbreak to protect plants.
Space is at a premium, so gardening needs to make the best use of space. If you have lawn space, you can densely plant as shown. There is no reason to grow things in rows. Rows are designed to facilitate machinery and tools. You don’t need to limit your growing area by making rows.
Make sure your site has easy access and workable pathways that are at least 40 cm wide.
You can make use of vertical space and even balcony ceilings.
Whether growing in containers or on reclaimed lawn space, the following images give an idea of mulching and soil-building:
See Creating the Permaculture Balcony Garden for more information on growing in small spaces.
If you have about 40 square feet of indoor or greenhouse space to work with, aquaponics might be an option. Simply put, aquaponics are a mix of hydroponic plant production and aquaculture to produce fish. Hydroponics on its own can be somewhat tricky, but adding fish makes the system function more like an ecosystem. This results in a more self-regulating system. Systems that are smaller than 1000 litres are prone to sudden fluctuations in nitrogen levels that can lead to dead fish. Better to stick with larger systems.
Greywater and Rainwater
It is odd that the approach cities take to rain – a vital resource – is to shunt it as quickly as possible to a disposal site. Cities are full of hard, impervious surfaces; and water is carried out in storm drains as quickly as possible. If one were designing a city from scratch, the smart thing to do would be to apply the principle of slowing the flow of resources through a site by catching as much as possible.
You might have access to water off of hard surfaces such as roofs or pavement that can be captured and used for irrigation.
Greywater is another option for irrigation. In the time we have I can only scrape the surface, however. Greywater is any source of used household water, excluding that which comes toilets. Water from wash basins, kitchen sinks, baths and washing machines are all greywater. They can assist in growing trees or vegetable crops, but not root crops.
Intangible Structures
Cooperative action can help facilitate sustainable projects. Things like co-housing require a well-mapped, shared vision among the group – one of the reasons they so often fail. Establishing communities garden space, however, is a simpler matter. Then there are actions like Permablitzes. The permablitz is something started by my friend and colleague Dam Palmer and his company Permaculture Solutions in Melbourne. A permablitz is an event whereby a designer gets together with a large group of people and implements a permaculture garden in one day. Of course the planning takes more time than that, but the physical work is done all in one shot.
For a complete permaculture reworking of society, alternative structures need to be set up. This may seem like a pipe dream in Toronto, but the Australians are making headway in some places towards making this a reality. In the third world, taking this sort of approach can make a huge difference as there is no government structure serving the people to speak of.
First, create a map of the site. It needn’t be anything too fancy, just something you can use for planning purposes. Freehand maps will do fine.
After laying out the paths, you will know what floor space is available to you. Now you need to consider sun exposure and wind direction. You’ll generally be placing taller plants so that they do not obstruct the sunlight of other plants. You may need to break this guideline if you need either the taller plants such as bamboo or a trellis to act as a windbreak to prevent wind damage to other plants. In arid conditions, the additional shade from taller plants or trellises can be beneficial by helping to retain soil moisture.
The installation of trellises will also help us to grow plants up walls and across ceilings. A trellis with a mesh pattern is good for plants that climb using tendrils such as grapes and bitter melon (Momordica charantia). Poles or lengths of string can be used for plants like beans or hops (Humulus lupulus) that twist around objects as they grow. In addition to natural climbers, plants such as squash and kiwis (which have a variety of species suited to climates from sub-tropical to cold temperate) can be tied to trellises to grow where you want them to. An added benefit of climbing plants is that they shade buildings in the summer, helping them to stay cooler.
First, put in a base layer of soil – either sand or potting soil – about 15 cm (6 inches) thick or more, depending on how deep the planter is. Place some of the natural soil you collected outside in the planter. Water the soil. The deeper the planter, the more you can put in. Next, add a dusting of compost on top of the soil followed by 10 cm (4 inches) of mulch and water it. Next add about 5 cm (2 inches) of compost and water it. Finally, add on about 5 cm of mulch and water it.
The mulch serves several purposes: it suppresses the growth of weeds, it helps retain moisture in the soil, it breaks down over time to feed the soil, and it creates a niche for spiders, which will help control any unwanted pests that show up. This mulch is a key element, and without it your garden will be less likely to be successful and will surely take more effort from you to maintain.
It will be helpful if you sow white clover seeds (Trifolium repens) in the mulch. Just sprinkling it on top will do. As the clover grows, it will create a weed-suppressing groundcover and it will fix atmospheric nitrogen into the soil, helping to fertilise your garden naturally. Groundcover also reduces soil moisture loss due to evaporation.