Abstract
There are many aspects to establishing successful tree crop systems that, perhaps, are not considered in conventional planning.

If you walk around the gardens here, there is a lot of wasted space. It is wasted on one level because people still use it, they come here and walk on the lawns, and so on, but mostly, there isn't food. On the way in this morning, I found some macadamias growing. Somebody has planted some food here. But, we could have a whole food forest here, feeding the campus. All of the food from the campus for the campus, could be grown here, so we don't have to bring it in from anywhere. It is about having the food where the people are. Not having to bring the food to the people, as much as possible. That is one of the principles of permaculture, to try to get rid of transportation. We shouldn't need to transport food. In very, very high density, that is not going to work. In permaculture we evaluate high density. How can we maybe move some people out and bring more food in to city centres.

I am going to look at the idea of integrating tree crops into a whole farm design or whole property design. There are some basic permaculture principles which I will draw upon. The first is the idea of diversity. It was always said that diversity is stability. As system that has diversity has some kind of stability. It actually goes a little bit deeper than that, because it is not just the diversity of the system but how well the components work together. This is really important. I am always experimenting with new plants. Plants which I have no idea, often, what the fruit tastes like. I often have no idea what the tree is going to grow to look like, let alone to know what good companions it might have. For example, the other day, I was researching Jubaea chilensis, which is the Chilean Wine Palm. It will grow very well in this climate. It comes from sandy soils in Chile. Perth is all sandy soils. It thrives in these conditions, but will tolerate much colder conditions. It grows well in Melbourne, Adelaide, and Sydney. In the process of researching the plant, I discovered a cactus that grows beside it in the wild, which is another plant I have, Tricocereus chilensis. That has an edible fruit, and also has medicinal uses, for treating tumours. It looks like it could be a very important plant in the future. I don't know, I am experimenting with it. Now that I have these little seedlings, I know that I will plant those together, because they work together in the wild. Often we don't have those links, so we experiment. We use intuition. But knowing that the palm grows beside cacti won't limit me to just that one species of cactus, either. I will experiment with other species.

Diversity makes a lot of sense in terms of the stability of the system. It also makes a lot of economic sense in terms of the stability of the crop. If, for example, one were growing chestnuts, and that is all they were growing, and the market falls out of chestnuts, the world market is suddenly flooded with chestnuts, bad luck. It's gone, you are finished. If, however, you also have some macadamias, half a dozen different kinds of tree crops, you are then in a position such that if the market falls in one kind, there are other things. But also, very important, as a producer, you should look at selling locally. People may not drive all the way to your property just to buy chestnuts. But if you have some chestnuts, some walnuts and some macadamia nuts, plus a few varieties of fruit, perhaps, they are more inclined to come and see you. Not only that, but when they get there, they are going to go away with quite a parcel. Whereas, if they were just coming for one thing, they would just take a fraction of that. I always encourage people, rather than going for just a single crop, why not aim for self-reliance. Aim for self-reliance plus, so that you have all these things happening, and you can supply three or four families around you with all of their needs. You won't get a better market than that. It doesn't matter what happens globally with the economy. You have always got a few people around you that are prepared to come and purchase food from you. You also have local support and feedback. You have direct feedback from your consumers which large crop people don't have.

Then, of course, if you are doing that, you will find a few crops which are especially easy for your situation, which do extremely well, or just suit your lifestyle. Maybe you don't really have to think about those things except at harvest time. Those are good plants to perhaps carry on and do cash crops with. Then you can commit those to a wider market if you wish.

The other aspect of diversity is that we are losing ground very quickly. On the planet we are losing...In the time we have spent here this morning, we have probably lost a hundred species, never to be seen again. They're gone. No amount of genetic engineering, no amount of selective breeding is going to give us those species again. So, we really have to concentrate on the diversity of life. I am especially interested in tracking down plants which have potential uses, which perhaps had uses historically. The whole study of ethnobotany and the uses that people put to plants especially interests me: to find these plants which are not part of the mainstream, but which, perhaps, are at risk in their own environments. It is very hard to find plants that are not at risk in their own environments. Globally, things are at risk. If we can start to find plants which we are prepared to have a little bit of experiment with...adopt a species. For goodness' sake, find a species that is at risk, and adopt it. Get some seeds, grow it. There are many plants today which do not exist in the wild. The date palm no longer occurs as a naturally wild plant in the original habitat. The jujubes no longer exist in the wild. The Quito palm of the Andes no longer exists in the wild. There are many examples of plants which are now extinct in the wild and are only cultivated. I think it is a good call for us to adopt a species.

A lot of these are long-term crops. Someone said to me one day when I was showing them a palm at home, "Are you ever going to live to see that fruit?" I said, "I don't know, but it doesn't matter." It is beyond me, it is for the common good, that we are doing a lot of the work that we are doing. I think, in there somewhere, we have to leave a little bit of room for that kind of work. That doesn't mean the whole property has to be dedicated to the future, in terms of not getting any food today. But that we have to be working towards that. It is people in situations like yourselves who are more likely to do that, than people who are involved in totally mainstream society.

Of course, the other aspect of that is the heirloom varieties of fruit and nuts. Especially the fruits. There are literally thousands of apple tree varieties that have been lost around the world, because the market demands that people are only eating three or four different varieties. A lot of those varieties are lost. I know of several people in Canada and a few in Australia who are collecting heirloom varieties and just keeping them going. It is like a botanic ark. It is something that is very, very necessary at this time in history.

One of the things that we do in permaculture when we are looking at a particular element, I use the word 'element' perhaps a little bit loosely...a particular part of the system, we may be interested in a particular tree as a crop. So we can treat that tree as an element in the system. We can do a little bit of an analysis of that element that helps us to put it into a design. If we start with the element, we could get very specific but for the moment we will stay general. Other elements could be animals in the system, it could even be ourselves. We are all elements, if you like. That element has a very specific set of needs, to survive, and to survive well. We can list the needs for that element. It also has a set of products. That is where the producer is primarily thinking the hardest. "I'm going to get walnuts," for example. But there are a set of other products that we could be looking at. For example, with walnuts, the outer husk is a good worm medicine. Perhaps we could make a herbal remedy for worms from this by-product. There are a lot of different products that we tend not to think of. In the southwest, when I drive past Blue gum plantations, and see where they have taken the Blue gum trees away to make woodchips, there are just these big piles of leaves left behind. I think, "All that eucalyptus oil...." We could be utilising that.

An element also has a set of functions which is where we really start brainstorming in our design. A tree may be fire retardant, or it may be a fire hazard, we might have to protect it. Perhaps it is a fire retardant and we can put our tree crop into the system in such a way that it creates fire breaks. It may also be a good shade tree, so perhaps we can pack it into the system so it is providing shade for our animals, provided they are compatible. Or shelter for other crops. If we are thinking about functions that those things can serve, then we can put them into the system in a better way. Some plants are very good barriers to animals, so we can plant them in such a way that they create animal barriers. Some plants are very good at erosion control. If we plant them in places where they are serving that function, we are maximising those plants in our design. Always bearing in mind the plant's needs. It might have a particular soil type preference, a particular water requirement, temperature requirements. There may be a particular microclimate on the property that is most suitable for that plant's needs. On the other hand, that plant may create a particular microclimate which is good for something else. The American ginseng, for example, underneath the deciduous forest, makes a lot of sense, or various fungi underneath tree crops make a lot of sense. It is just a matter of thinking through how you are going to maximise the design. This is a very good tool for getting there.

The Chilean Wine Palm that I mentioned earlier probably will fruit for the first time in about ten years time. They are a miniature coconut, about the size of a macadamia, about as tough as a macadamia, but with the flavour of a coconut. I suspect it will be a long time before I am actually eating any of my own seeds, because I will be making those available, I will be growing those out and moving them out. One of our major products is more of the same, propagating material.

There are animals that will work in tree crop systems, and it really depends on what the crop is and what the animals are. We have to think that through. Certainly, if weeds are a problem under a tree crop, we can look at geese or ducks, chickens, perhaps. There are a lot of different options. It is certainly preferable to spraying, because they are cycling the nutrients back into the system.

The other thing that we think about here is threats to well-being. It is often a question of weed control with plants, of actually keeping rampant grasses at bay. There are plants you can grow under a tree which keep the weeds down. A classic example at home, is that we have had orchardists come to see what we are doing, and they say that we can get away with this because we don't have kikuyu grass. Forget it if you have kikuyu. I just kind of reach over into the middle of the herbs and pull out a strand of kikuyu. They are kind of shocked, and wonder why the kikuyu hasn't taken over the whole system. Because it is in balance, is the answer. There is a natural balance there. Also, we practice a little pattern we call 'weed to feed.' If we see kikuyu coming out, we just grab it and throw it to feed the chickens or pigs. It is also a certain amount of selection on our behalf. We won't let it get that rampant. In certain places on our property, we allow it to become that rampant. One of our threats to well-being are kangaroos. We don't like fencing them out, but at this time of year towards the end of summer, they are very hungry and they come in from a long way. They actually eat the kikuyu grass down and that takes a lot of pressure off the rest of our plants. So we encourage a certain amount of kikuyu grass.

It is a way of thinking around threats to well-being. One note about the use of pesticides: throughout the world, wherever pesticides are used, the following season a new problem occurs. That is a blanket rule. As soon as pesticides are laid out, it doesn't just attack the target--it takes out a whole host of predators as well, at which point you strike a new imbalance. And you are on what we call the pesticide treadmill from there on. So, it is very, very important to try to think your way around the use of pesticides, or you will be on that treadmill, supporting multinational companies for the rest of your career.

A final word about the concept of stacking. In a forest situation you will get a tree at this height, a tree at this height, groundcover, and they do all function very well together. But, they evolved that way. For example, there may be twenty or thirty trees at this height which never survived. They just sat there and perhaps finally died because they never achieved, because this one was already there. Something else that likes to live in the shade comes up. So, if we are designing a system we have to think about that process. We have to think about where the opportunities are for the plant we want to put in. Rather than going out and planting a hundred trees where only two or three are going to survive, which tends to happen in nature. We have to think beyond that and ask, where are the best opportunities for this particular plant? Where can we stack it in the system?

One of the things I am looking at now in the orchard, where there might be a fairly ordinary orchard structure, is coming in afterwards and retro-planting with some palms. Palms don't produce a huge amount of shade, but they do produce some. Generally speaking, they are very good at buffering ultraviolet light. Certainly, in the southwest, we are getting increasingly higher UV levels. Exactly what effect that is going to have on our crops, we don't know. This is one way we can look at perhaps buffering that. There will be increased water use, in a situation like that, because you have more plants drawing water. That is a big issue in the southwest. It is not necessarily an issue everywhere else. But we can always be looking for more things we can stack into the system. What other productive part of the system can we have. You might have chickens running in under the trees. Put a couple of beehives in and you have another whole system operating. Put some ponds in underneath. You are increasing the humidity of the system, creating traps for a lot of insects and adding a whole new set of products to the system. If you arrange a pond at the top of the orchard, and you have geese or ducks going through the system, they always go back to this pond, and they are dumping huge amounts of manure into the water. So you have a high-nutrient liquid manure you can be putting back onto the trees, for example.

If you are starting off with a conventional fruit tree system, I would argue that it is not a stable ecology, that it needs a lot of different equalising effects, perhaps pesticides, perhaps fertilisers. Whereas, what we are doing is working towards a stable ecology, in that sense. In the end, the only nutrient losses should be the product that you take off the place. In a situation where pesticides are being used, you can't generally, productively, use poultry for a long time. You can use them, but you wouldn't eat the meat or the eggs. So you perhaps have a long wait before it is fully productive.