Mollison's design principles

Where the rules come from

Bill Mollison was a naturalist first and a theorist second. His great handbook, Permaculture: A Designers' Manual (1988), is full of observations from forests, coasts and drylands, but it does not open with a numbered list of principles. It speaks instead of attitudes such as working with nature rather than against it, and of the insight that every living thing shapes its surroundings. Only in Introduction to Permaculture (1991), written with Reny Mia Slay, did Mollison gather his design rules into the form that permaculture courses have taught ever since. They are usually taught as eleven groups.

These rules are close to the ground: they tell a designer where to place a pond and how to read slope and wind. Eleven years later David Holmgren published his twelve principles, which work more as general thinking tools. Both lists rest on the same three ethics.

The rules one by one

Relative location. Every element is placed in relation to the others so that they help each other. The compost stands between kitchen and garden, the water tank above the beds it supplies, so that gravity does the work.

Each element performs many functions. A pond stores water, cools the air and gives animals something to drink. A hedge of nitrogen-fixing plants breaks the wind, feeds the soil when pruned and supplies mulch. The plant guild is this rule applied to a single tree and its companions.

Each important function is supported by many elements. Water, food and fire should never hang on one source alone. A garden can draw water from a roof cistern, from rainwater harvesting in the soil and from swales on the slope, so that the failure of one does not ruin the whole.

Efficient energy planning. Here Mollison brought together three tools. Zones place whatever needs daily care close to the house and whatever needs little care further out. Sectors map the energies that come from outside, such as sun, wind, fire and the flow of water. Slope decides where water and cold air run, and where gravity can carry water instead of a pump; keyline design grew from the same way of reading land.

Using biological resources. Living helpers take over work that would otherwise need fuel or purchased inputs: nitrogen fixers feed the soil, worms loosen it, hens scratch and manure.

Energy cycling. What enters a site should be used several times before it leaves. Kitchen scraps go into compost, prunings become mulch, and the energy stored in wood and humus passes from one use to the next. The page on energy flow explains why this is a practical aim rather than a law of physics.

Small-scale intensive systems. A small area, well tended, can give more than a large one that is poorly cared for. Mollison spoke of plant stacking, layering plants from tall trees down to ground cover as in a food forest, and of time stacking, letting crops follow and overlap each other through the year; the page on stacking in space and time explains both.

Accelerating succession and evolution. Nature heals bare ground in stages, from pioneers to mature woodland. The designer can use this sequence and speed it up by planting fast-growing pioneer plants and nurse trees that build soil and shade, and then guiding them toward the target species. Ecological succession and syntropic agriculture show how far this idea reaches.

Diversity. What matters is not the number of species alone but how many useful connections exist between them. Polyculture and guilds spread risk and create many small exchanges.

Edge effect. Where two habitats meet, life is especially rich: at the shore of a pond, at the edge of a wood, along a hedge. Designers deliberately lengthen and shape such edges. The herb spiral packs many small edges and microclimates into a few square metres.

Attitudes. Mollison closed with rules about the designer's way of thinking. Everything works both ways: whether something is a problem or a resource depends on how we look at it. In the same spirit he is widely credited with the phrase that the problem is the solution. Permaculture, he taught, is intensive in information and imagination rather than in capital or land. Holmgren later added, in an essay of his own, that solutions can also turn back into problems.

Mollison and Holmgren side by side

Holmgren knew Mollison's rules well, and his twelve principles are a different cut through the same material rather than a replacement. Any comparison is a matter of reading, not of fixed equations; Permaculture West, which sets the two lists next to each other, says so plainly. This is how we read the overlap.

• Close matches. Relative location and integrate rather than segregate describe the same idea: right things in the right place, connected. The two rules about many functions and many elements fit here too. Using biological resources corresponds to use and value renewable resources and services. Diversity corresponds to use and value diversity, and the edge effect to use edges and value the marginal.
• Partly matching. Energy planning with zones, sectors and slope lives on in design from patterns to details, where zones become one pattern among many. Energy cycling is spread over catch and store energy and produce no waste. Small-scale intensive systems meet use small and slow solutions in the word small, while Holmgren adds slowness; Permaculture West pairs them with obtain a yield instead, because a small, well-tended area gives a high return. Mollison's attitudes reappear in creatively use and respond to change.
• A real tension. Mollison wants to accelerate succession; Holmgren advises small and slow solutions. Permaculture West still sets the two side by side, and they do meet where the designer speeds up nature's own sequence with modest steps instead of forcing a result with machines and fuel.
• Only in Holmgren's list. Observe and interact, obtain a yield and apply self-regulation and accept feedback have no rule of their own in Mollison's list. Long observation and a real harvest run through all of Mollison's teaching, but Holmgren was the one who made them principles. Feedback comes from systems thinking and is his clearest addition.
• Only in Mollison's list. Concrete tools such as zones, sectors, plant stacking and time stacking appear in Holmgren's book as examples, not as principles of their own.

Why both lists are worth knowing

Mollison's rules help when a plan is drawn: where the pond goes, which plants stand together, how the path runs. Holmgren's principles also help where a question is not about land at all, such as how a household or a village can live within its limits.

The rules at Sa Medada

Sa Medada is a slope in Jerzu, in Ogliastra on the east side of Sardinia, with a dry season that lasts roughly from May to September. The LiDAR wetness map shows a comparatively dry main area with moister channels along the edges, so slope and water decide much of the design. Swales are planned; none has been built yet.

Several nitrogen fixers already grow in the ground as a biological resource, among them Tephrosia, the coral tree, Inga edulis and Leucaena. Project Eden begins with pioneer plants, ground cover and holding water, and wants to speed up succession in the way Mollison described.