(A subtropical permaculture garden makes use of every available bit of space for food-growing and recycles whatever it can)
The principles of a permaculture lifestyle work well in the tropics and subtropics but certain principles need to be understood.
When I first started practicing this type of home food-production 30 or so years ago I based my methods on those evolved for colder climates where the difference between growing seasons is more marked – bearing in mind the Father of Permaculture Bill Mollison lived in Tasmania. I soon learned that adjustments needed to be made for my sub-tropical garden – also bearing in mind Bill’s oft-quoted statement that permaculture is a philosophy of working with rather than against nature. As opposed, of course, to AGRIculture, which works against it.
This, to me, remains the essence of a permaculture garden. Permaculture is based on fine and lofty principles but for most of us it comes down to a practical way of turning our own backyard (and if possible our front yard too) into a self-sustaining source of good food, grown as “naturally” as possible without manufactured chemicals and pesticides and with due regard to the surrounding environment. Though as the latter is usually other people’s non-permaculture gardens this aspect is less important to the average home gardener. I believe that understanding and adhering to the PRINCIPLE of permaculture is what is most important here, not sticking to every last finicky tenet of a practice that lends itself to infinite personal application.
So, before I get on to the different approaches dictated by a hot climate, here are what I see as the essential principles of permaculture for the average home gardener.
- A design that takes into account natural landform, rainfall, water collection and distribution, basic soil type, neighbourhood constraints (or advantages), available sunlight throughout the day, local climate factors such as frost likelihood and wind force/ frequency/direction, sources and types of available power (mains electricity, solar, generator, wind etc), local authority constraints and requirements.
- Understanding of the biodiversity of natural and /or existing vegetation including common weed types. Assess what can be useful either as food (human and animal) or soil improvement (through composting/green manuring) and what must be eliminated.
- Planning that takes into account age and capability of householders/gardeners and amount of food required. (No point in growing more than you need though some excess to give away, sell or re-process into food for the soil is usually a good thing).
- Diversity of crops and critters; in diversity lies strength, interesting and healthy variety, and the ability to resist insects, diseases and natural disasters
- Turning as many factors and features as possible into renewable resources – animal, vegetable or mineral. Very few organic things can’t be recycled through permaculture.
- Integrating growing areas so that you get aggregated benefits. For example “edible fences” of vine crops to divide one section from another, or hedges of fruit/berry-bearing shrubs, or pathways of herbs, or low herbal plantings to separate one crop from another. This makes more complete use of available (including vertical) space and has added benefits of surrounding susceptible crops with barriers of insect-repelling herbs. Always look at a bit of garden and say “how could I use this more productively?”
And here’s a little principle of my own – grow lots of flowers! Some flowers are edible, some (pyrethrum) have insecticidal benefits, others smell delightfully and all are beautiful. Your permaculture garden should be a place of delight and recreation as well as a food source or what the hell’s the point of it all? It only takes a little effort to reap a great reward when it comes to adding scent and colour to your vegie crops. Also, flowers attract beneficial pollinators and while some of these (butterflies) will certainly produce leaf-munching caterpillars an overall benefit of flowers is that they serve to confuse potentially harmful insects with an abundance of choice. I’ve always been a great fan of potager gardens where flowers and edible crops exist happily together.
Canning the heat
Hot climates (subtropical and tropical) have both benefits and disadvantages. These can be summarised as:
Crops can be grown all year round, with some seasonal adjustment making it possible to grow the traditional “cold climate” fruits and vegetables of the European/western diet in the cooler season (especially in the subtropics). At the same time, in summer, it’s possible to grow crops such as taro, cassava, chillis and edible ginger. A far greater range of fruit trees can be grown in hot climates – bananas, guavas, mangoes, sapote, custard apples etc. Some varieties of apples as well as peaches, nectarines, blueberries and strawberries can be grown in the sub-tropics, especially in upland areas. Avocados thrive there too. In fact a subtropical climate is just about the best there is when it comes to growing your own food.
Rainfall is plentiful, HOWEVER, it usually falls to a monsoonal pattern, in an immoderate amount that washes away soil and its nutrients, erodes earthworks such as ditches, mounds and swales, damages delicate leaves and fruit. Most important of all, distribution is uneven and unreliable with periods of intense, heavy rain being followed by even longer periods of no rain at all.
Sunshine makes plants grow fast and strong. Yet it can be so intense that it burns leaves, flowers and fruits; too much of it has a drying effect that reduces the moisture content of plants, so they are less “juicy”.
High humidity encourages growth but also encourages the development of moulds and fungal diseases.
Lack of frost is generally regarded as a benefit when growing food crops – but some root vegetables need frost and cool topsoil to develop full size and flavour.
While a greater abundance and variety of crops is possible in a hot climate this is matched by a greater abundance of insects and weeds. How you handle these two “problems” is one of the most important challenges faced by hot climate permaculturists.
Making compost is easier and much faster in a hot climate and you can do it all year round. However, once in the soil, compost breaks down faster and needs more frequent application – and this goes for any sort of fertiliser.
And let’s not forget that permaculture is not just about plants…
In a cold climate animals need indoor protection during winter and they are more subject to illnesses caused (or exacerbated) by cold and damp. In a hot climate they can stay in the open year round but they will be vulnerable to insect infestation and annoyance (ticks, worms, flies, maggots) and heat exhaustion. Clean water must be provided more frequently.
Permaculture in a hot climate takes a greater toll on the gardener in many ways. Of course, you don’t have to contend with ice and snow and a bleak, cropless garden that may even be covered in snow for several months. You don’t have to suffer the urgency that comes with having to get everything harvested by a certain date and then appropriately stored for winter – there’s not the same need for pickling, preserving and processing. In a hot climate permaculture garden you can have some fresh crops all year round and adjust your eating habits to your season, with just a little jam-making and pickling – and probably some freezing too – if you enjoy doing that sort of thing. The downside is that you can’t ever take a break. No sitting over a winter fire for a few months of pleasurable garden inactivity, pouring over your seed catalogues! Permaculture in a hot climate means permanent labour! And vigilance!
Part of the permaculture philosophy is to reduce human labour. So don’t bite off more than you can chew. If you have a large garden – more than half an acre say – set aside a section of it for permaculture development. You can always expand as required, once you’ve mastered the principles and put them into productive practice.
In its purest form, permaculture embraces both land and dwelling place in one self-sustaining practice. This wholistic approach means that your house should be built of renewable or non-environmentally threatening materials (mud brick, underground, wattle-and-daub, recycled bricks and timber), your water should be collected on site, and all your energy should be sourced from sun or wind. Such an admirably idealistic approach is way outside the scope of my expertise; for the purposes of this article I’m assuming my readers live in “normal” suburban homes built on typical suburban lots or small acreages. Even so, I would expect them to have them to get at least some of their power from solar panels and have tanks to collect rainwater.
“Good” soils are more frequently found in cold rather than hot climates (I may go into this in detail in a later article but for now, take my word for it!). Even the soil that sustains large and complex vegetation systems such as rainforest breaks down quickly once exposed to the elements. So garden soil in the tropics and subtropics needs to be thoroughly dug over once, to a depth of about half a metre (deeper would be even better but we are talking about the possible here). This is quite deep enough for all vegetables and also young fruit trees. (If you are planting larger fruit trees then the planting holes need to be deeper and wider – but this is another issue). You can do this bit by bit though it would be more desirable to get the whole cropping area done at once, before any planting takes place. Yes, it’s possible to grow your crops in raised vegetable beds as many do, but we are talking PERMACULTURE here and long-term sustainability means getting as much of your growing as possible done in a deep, sustaining soil that can be regularly renewed for years to come. There are extreme circumstances (very steep slopes, unworkably heavy or shaley soil) where alternatives to in-ground growing have to be considered but as a general rule it is best to take your natural soil, and its natural profile, and work it into a suitable growing tilth. This will take time and effort. In the meantime you might be looking at alternatives (raised beds, containers, straw bales) but in the end successful permaculture depends on good soil. The goal is a soil that is dark brown to black in colour, not too heavy and sticky, nor too light and sandy, and which crumbles nicely in your hand. (If you want to know all about soil you can buy my e-book Improving Your Soil – The Natural Way for $4.95 at http://www.amazon.com/Improving-Your-Soil-GardenEzi-ebook/dp/B007IXY6Y8.)
It’s also important to raise or lower the pH level of your soil so that it lies in the neutral zone between acid and alkaline. This will suit most crops. Those that require higher or lower levels of acidity or alkalinity will require localised adjustments. (This is outside the scope of the current article – but look for further detailed articles on this subject – there are some on this website).
Adding a cover of organic matter is the way to improve soil texture and consistency and once it is added to soil that’s been opened up and worked you’ll be amazed just how quickly this takes effect. Again, you’ll find detailed information on suitable mulches in my soil book. As a guiding principle, the best mulches for soil improvement in a hot climate are the straw residue of crops such as sugar cane (excellent for breaking down heavy clay), pea, bean and lucerne. Fine bark is good, especially if you wish to acidify your soil (but bear in mind that many vegetable and herb crops require a slightly alkaline soil). The hotter your climate the more frequently you need to apply mulch but usually laying a good thick cover twice a year in mid-spring when the ground begins to warm up after the cool season and again in late summer will be sufficient. Topping up in between if required. The rule that you should never mulch dry ground is even more important in a hot climate where the evaporation rate is so high. If there has been no rainfall always water the ground before applying mulch. And keep it loose enough so rain can penetrate through to the soil.
Making your own compost is an essential part of permaculture practice. In a hot climate it’s faster and easier. Just about anything organic can recycled into compost and used to enrich your soil. Apply twice a year when mulching as your regular practice but top up every month in the main spring/summer growing season and you won’t need to provide any other plant food. There is no better way of creating a really wonderful, rich, growing environment. Obviously you will use your chook poo and old nesting/laying straw from the hen house as well as manure from any other animals you keep (except dogs and cats!). But unless you have your own cows or other pasture animals in sufficient numbers to provide worthwhile manure, you’ll need to buy in a few bags a year. A mixed manure such as Searle’s 5 In 1, formulated in an for a hot climate, is particularly good.
Weeds proliferate in the hot climate garden so don’t waste time trying to control them; harvest them for compost, turn them into a nutritional and biocidal “tea” or let your livestock eat them. Chickens, ducks and geese all eat weeds. So do goats, rabbits and guinea pigs. Of course you’ll need to manage your livestock so that they can get at the weeds without eating the vegies and herbs. The best way of doing this is by fencing off the vulnerable areas and allowing livestock free reign to keep weeds down in the in-between areas such as fallowing beds, pathways and the ground around fruit trees (if this isn’t already planted to some lower-growing crop). Poultry and small animals can be kept in mobile cages that can be moved from one area to another. A goat can be tethered.
Weeds also play a role in attracting beneficial insects to the garden. They also attract pest insects and this can be a bonus too because, like cultivated flowers, they help to confuse the pests and provide alternative food to your valuable crops. Of course, you don’t want weeds in your growing beds competing for water, nutrients and sunlight with your vegies. Here you will use suppression techniques such as layered newspaper or cardboard or straw mulch, and be regular and vigilant in hand-removal. But I’ve seen permaculturists with flourishing weed borders around the edges of their beds and these seem to help lure pests away from the good stuff.
Many weeds have valuable nutritional AND biocidal properties. They can be gathered and put into a large container of hot (but not boiling water). Let this steep for a week or so then skim all the debris from the surface and strain through a sieve or coarse cloth. Pour or spray the brew over your plants – it will help condition the soil as well as encourage healthier plants. Throw the mucky, smelly vegetative residue into the compost heap. Nothing is wasted in the permaculture garden!
There are SOME weeds that are so anti-social that you do need to get rid of them, especially if their proliferation is likely to become a problem in neighbouring gardens or adjacent bushland. Those which produce numerous seeds that stick or adhere to clothing are a problem, as are weeds poisonous to livestock. They should be thoroughly exterminated by whichever method suits you best. The really important thing here is to GET TO KNOW YOUR WEEDS. Study the weeds in your garden as you would any other plant and learn which ones to throw away and which ones to keep – like poker!
I like lots of insects in my garden. It’s the sign of a healthy and diverse biosystem. They pollinate plants, make honey, feed birds and frogs and livestock, some even prey on plant pests. And of course a few – a very annoying few – of these insects ARE plant pests. Chemical killers have no place in permaculture. Instead, we have to focus on repulsion. And now I’m going to say something very controversial – in all my years of growing things I have never yet come across a really effective insect repellent for the home garden. And let’s forget the word “chemical” here – everything in nature is full of chemicals. And that includes all the so-called “natural” repellents such as garlic, Quassia chips, Neem, soap, eucalyptus and ti-tree oil. They owe whatever anti-insect properties they may possess to their chemical constituents. True, they can’t poison you in the way that manufactured and/or extracted chemicals can do – which is also why they don’t really work. Some of the sprays made from these plants can have a short-term repelling effect on some insects but this is too short to be worthwhile – you need to spray at least once a day and more if it rains.
The only really effective way of keeping nuisance insects at bay is too put up a barrier. Grow your vulnerable fruits and vegetables under netting. Be vigilant with the rest; do a daily patrol to pick off seasonal infestations of beetles, caterpillars and grubs (spraying with any vegetable oil or just detergent and water will get rid of large infestations). If your garden is a welcome place for birds and frogs, and if you have insectivorous livestock, then these critters will all help keep the number of pests down. As with all permaculture practice, a multi-faceted approach usually gets the best results.
The efficient collection of water is a major part of permaculture practice and this is even more important in a hot climate where rainfall is very seasonal and the evaporation rate high. The roof of every structure on the lot should be used to collect water, channelling it into rainwater tanks. The more the merrier! Take advantage of natural contours on your land to create swales (large shallow channels with comparatively high, rounded banks on each side) to direct water to in-ground collection points such as ponds or underground cisterns. Smaller channels can be dug to guide rain runoff onto garden beds and all beds should be raised in the middle with ditches around the edges. In this way, very little precious rainwater is wasted and can be stored until needed. The creation of swales and ditches also gives you control of heavy monsoonal deluges, channelling the water away from where it can cause erosion or waterlogging and into collection points.
Permaculture practice integrates animal and vegetable. It IS possible of course to adapt the permaculture philosophy to small gardens where no livestock can be kept. In such cases, animal manures will need to be purchased. Keeping livestock adds a whole new dimension to basic gardening practice and means more responsibility and hard work but most permaculturists accept this, even if they only have room for a small hen coop. Chickens, in fact, are very little trouble to keep, considering their many benefits. It’s possible to design chicken houses and mobile structures that are almost self-sustaining and advice on how to do this can be found on the internet. Along with advice on the best breeds for your purpose. Chickens not only lay eggs and provide very nutritious poo but are great consumers of weeds and insects. If you live in a suburb chickens (without a rooster) are probably all you’ll be allowed to keep. But if you have a few acres/hectares then you can keep other poultry (geese, ducks, guinea fowl) and perhaps a goat or two. Cows are too much hard work for the average permaculture gardener and require special handling. Goats are a much better bet and though they need good management if they are not to gobble up your vegies and ornamental plants, their eclectic appetites make short work of weeds. And of course they produce milk, cheese and manure. They are also able to tolerate heat, if you buy the right breed.
Do not despise guinea pigs in the home garden. They make good pets for the kids and if you keep them in movable cages they can graze different parts of the garden, keeping down weeds and consuming unwanted vegetative matter such as carrot tops and the outer leaves of brassicas. Their manure is not copious (unless you keep a lot of them) but it’s useful in the compost heap. And you can keep quite a few of these clean, lovable little critters in a small backyard.
If you live in a hot climate, the permaculture system offers a better chance of successful fruit and vegetable growing than the traditional English-style neat-beds-in-a-row type system. The somewhat chaotic-appearing profusion of a garden developed along permaculture lines, in which just about every bit of ground is used to grow something, tends to confuse insect predators by its very abundance. Instead of the hard and arbitrary division of beds by bricks or sleepers, growing areas and working/walking areas flow seamlessly into one another with only plants dictating the areas of separation. This more natural approach also fosters disease-resistance: vegetables grown in beds isolated from other crops are the most prone to fungal and other diseases. The recycling of all organic waste keeps the soil replenished despite the constant assault of sun and heavy rain alternating with drought. The use of livestock adds the necessary balance to create a “natural” system and helps with pest control. The creation of a living jungle of edible plants is, once established, a lot easier to maintain than lawns and neat flowerbeds and sterile paved pathways. What’s more, all this vegetation cools the air around your house. If you don’t believe me, try taking your deckchair out into your green permaculture paradise and comparing this with sitting on a paved patio.