Call to Order


By using polycultures and diversity of beneficial species, we can create productive living ecosystems that reflect a harmonious natural order.

We often hear about how important biodiversity is to natural habitats, but that significance extends to all living things, including us. Our own bodies are flourishing microcosms buzzing with life. We live in a symbiotic relationship with 300-500 different types of gut bacteria, whose presence is crucial to our health.

There are around 100 trillion of these bacteria inside each of us – that’s 10 times the number of cells in our body! The lesson here is that all biological organisms live in complex relationships with their own species, with other specifies and with their environment. That’s what the science of ecology is all about.

As gardeners, we can’t ignore this fact because no garden or farm is exempt from the laws of ecology. In the ecological design system of permaculture, biodiversity is addressed in the design principle referred to as the diversity principle, which promotes the use of polycultures and a variety of beneficial species to create productive systems where specifies interact co-operatively.

This principle is quite a complex one, built upon several ecological concepts that we must first understand to fully comprehend its scope and intent.


A key element of the diversity principle is the concept of a polyculture, which is where more than one species of plant or animal are raised together at the same and in the same place. Polycultures are the norm on planet Earth; nature forms stable ecosystems from different species that can coexist in beneficial relationships with one another.

In agriculture, it’s common to see monocultures consisting of just a single species. These are human-conceived artificial systems. They don’t exist naturally because monocultures are ecologically unstable and lose integrity over time. If a field of lettuce is left on its own for a year, it won’t remain that way.

In contrast, when polycultures are left on their own, they increase instability and resilience as the number of harmonious relationships between the different species increases over time. They also develop a high degree of natural order, but this is not the same “order” we associate with artificial human systems.

When discussing polycultures, it’s important to point out that nature will build ecosystems from whatever species are present, irrespective of whether they’re indigenous, native or exotic, as these groupings are human concepts and nature doesn’t discriminate. Ecosystems are dynamic, ever-changing, living systems and plants have evolved to move around the planet. They’ve been doing so for hundreds of millions of years.


A critical failing in horticulture design is the lack of distinction between ecological order and aesthetic order. A traditional English garden with its immaculately pruned hedges, highly structured perennial borders and manicured garden beds is thought to display more order than a tropical rainforest – but humans mistake tidiness for order! They are not the same in respect to living systems.

Formal gardens take the conventional gardening/farming philosophy of “humans dominating nature” to its ultimate expression. They reflect how humans picture plants should grow, not how nature actually grows plants.

The following attributes are common to artificial human systems and set them apart from natural systems:


  • Artificial groupings: plants grouped by species, colour, texture, leaf shape etc.
  • Rectilinear designs: use of unnatural shapes such as straight lines, squares and rectangles.
  • Strict planting patterns: plantings in repetitive patterns such as rows.
  • Monocultures: mass plantings with large areas filed with one type of plant.
  • Highly defined boundaries: areas clearly partitioned and separated from each other with a strong emphasis on where growing areas end and begin.
  • Energy inefficiency: excessive energy and labour required to maintain the level of tidiness.

The primary reason conventional gardens are designed this way is aesthetics. Plants are generally not as organisms that exist in complex ecological relationships to one another and their environment, but more as inanimate “design features” that can be used for human artistic expression.

In farms, the design motivation is purely convenience. Plants are seen as pure convenience. Plants are seen as resources to be exploited for profit and monocultures planted in rows facilitate harvest by machine or by hand. Planting monocultures also serves commercial demand by supplying huge volumes of one type of crop all at once.

This is quite the opposite to what you would do when feeding a family or sustainable community, where the goal would be extended cropping of a variety of produce throughout the year. Maintaining unnatural order in these artificial systems comes at a cost: waste of energy and resources, extensive ecological damage, widespread pollution and often a reliance on harmful chemicals.

Nature’s motivation is to create natural order, which can be defined as the harmonious relationship and cooperation between different species, which enable an ecosystem to function as a whole integrated living system. Permaculture design teaches us that by emulating natural order we can gain many positive benefits such higher yields, less water and fertiliser usage, natural pest and disease control – all for less effort. Basically, more outputs for less inputs.


Biodiversity isn’t achieved by placing a random collection of different species together. What’s most important is not the total number of elements in the system but rather the total number of functional relationships between the elements in the system.

How do we create a natural order? We do this by carefully selecting species that will work together and by devising any species that may be detrimental to each other.

  • Most species in nature, probably around 80 per cent, can coexist and interact without any ill effects because they have no effect on each other, which is why random plantings in most gardens still work.
  • Some species in nature, probably around 10-15 per cent, when grown together greatly assist each other in beneficial ways, as seen in the practices of companion planting and guild planting.
  • While many plant species may compete with others for water, nutrients and light, a minority of species may be detrimental to one another, such as allelopathic plants and trees that inhabit the growth of others or “bad companions” in companion planting. Certain plants species may encourage pests and diseases by acting as alternative hosts or by providing overwintering habitats for pests.
  • The addition of animal species can enhance a natural system but too many can stress and damage the system through overgrazing, soil compaction, destruction of plants and trees, and soil erosion.

In the design process, the tools we use to build beneficial relationships between species and their environment are an in-depth knowledge of the plant and animal species in question, a comprehensive set of ecological design principles such as those provided by the system of permaculture and a healthy dose of creativity.

Sure, this approach requires a lot more thought and planning, but it’s far more sustainable – and anything worthwhile takes effort.