Complexity is the key to sustainability. Complex systems such as biotic communities and cities run themselves but more simple systems such as automobiles and tractors need the regular intervention of technicians to keep them going. The parts of a simple system interact with each other in a linear way, as the way an engine drives a transmission which drives a differential and then the wheels. The parts of a complex mechanical system interact in a web-like fashion with lots of things happening at the same time. The action is manifold and simultaneous. The birds sing, the sun shines, plants grow, bees buzz and gophers dig...all at the same time. When human beings try to “fix” complex systems with technical interventions their efforts are, very often, counterproductive. Interventions such as spraying insecticides are met with countermoves within the system that neutralize their effectiveness, such as pesticide resistance. Medicine is replete with examples of physicians (with the best of intentions) killing their patients. When doctors go on strike, mortality drops. And so it is in agriculture. In 1990, crop losses from insects, diseases and weeds exceeded 42% yet 25 years earlier, notwithstanding very much increased applications of improved chemicals, losses were estimated at only 35%.

On a whole systems farm, interventions are a last resort. A fundamental principle is that the various species interact and through sets of feedback loops, maintain a kind of dynamic balance known as homeostasis. These interactions are so complex that few of us have much of a chance of understanding them. All we really have to know is that with sufficient complexity the system will take care of itself. If the whole systems farmer, in the course of a year, grows a hundred kinds of plants, most of the problems regular farmers have with pests and diseases will take care of themselves. There will be no need to identify pests and little need to intervene. There may be some losses, but the time and expense saved by not trying to fix problems will cover these losses--with interest.

For starters, the farmer can consider a number of marketable crop plants, both ornamental and edible. Flowers should be an important part of the mix because a number of parasites and predators of crop feeding pests feed on nectar when their preferred food isn’t available.

Then she can consider any of a vast number of field crops which can be purchased from seed suppliers or from grocery, feed and health food stores. These include beans, lentils, peas, sunflowers, popcorn, field corn, ornamental corn and flax. A nice variety of grasses are available in lawn mixes. Ryegrasses, annual and perennial are excellent candidates. Chicken-feed wheat from the feed store is one of our favorites and we also use it for making trays of wheatgrass that our customers buy for juicing. Pigeon feed and birdseed yield lots of interesting surprises and can add a great deal to the complexity we are looking for at an affordable price. For the most part, the above mentioned grasses and grains are grown for mulching. Locations can be in the alleys or on the beds. The poorer the soil is initially, the greater the proportion of these crops should be included. Some may say that growing crops that don’t get harvested or sold is a waste of space but to that I would reply, in the economy of natural systems nothing is wasted.

With the impending decline in petroleum and natural gas production, legumes will become an ever more important part of the plant mix. It is possible that as much as half the nitrogen in this world’s protoplasm has come from the industrial synthesis of ammonia (mostly by the Haber process) which, in effect, turns air into food, livestock and people. As supplies dwindle and prices increase, successful cultivation of these plants is one of our best hopes for sustainability. Thus, it may be well to give legumes high priority in the mix of things in the whole systems garden. At this time, I haven’t come close to making as good use of these plants as I would like. If a quarter or a third of the garden was planted to thriving legumes, I would think that a nice goal--at least initially while industrial fertilizers are still cheap and available. Annual legumes such as beans, peas and favas can be grown on the beds or in the alleys. For several years, I’ve been experimenting with alfalfa, sweetclover, and other clovers on the shoulders with the hope that they might seed themselves into the alleys and add to the winter cover there. This has promise, but as yet I’ve not been able to get them established thickly enough to expect to make much difference in nitrogen supply.

Now here’s something to think about: Each single macroorganism is actually a superorganism composed of and associated with hundreds of millions of bacteria, fungi, actinomycetes, nematodes and the like. Just the other day I was reading that a human being, by count of cells, is more bacterial than human--a kilogram of bacteria carried around in the gut alone. If we said, for the sake of discussion, that every plant species in the garden had a hundred species of microlife (and other macrolife, too) associated with it, then a garden of a hundred species could actually be a garden of 10,000 species, probably much more. To be sure, there will be some overlapping in the species each plant associates with, but many will be unique. It would be supremely arrogant and patently impossible for any human being no matter how many PhD’s or computers he may have, to try to keep track of these interactions. It is enough that the whole systems gardener recognizes, appreciates and celebrates this complexity. As a Zen master chops wood and carries water, the whole systems practitioner spreads her mulch and plants her seedlings in great variety.