Programmable Permaculture

March 1, 2013

NOTE: Images in this archived article have been removed.

Image RemovedThere’s a cultural phenomenon, one that has been growing for the past decade, of hobbyist hackers exemplified by Make Magazine and TechShop. These hackers want to have the experience of building something in the physical world while still applying the tools and techniques of computing. With the rise of open hardware platforms like Arduino—even whole systems like the Raspberry Pi for $25—it’s surprisingly affordable for people to program their own electronics.

The key to design when working on such projects is to decompose a problem into its constituent actions, to figure out what can be done by the programmable hardware vs. what must be done using other (e.g., more conventionally mechanical) components, and then to assemble the pieces into a working whole. While I can’t say I have any deep experience working on such projects, for some time I’ve been wondering whether the same ideas can be applied in a direction of more interest and perhaps of more importance.

How can we solve a problem (in a garden, say), with permaculture tools, by decomposing the problem and coming up with a set of interlocking pieces that solves it? Framing the problem in this way is very much applying an engineering mindset, something that might irk those who insist on thinking holistically about any and all ecological settings. (And I can relate to that sentiment, because too much has been done in engineering and science more broadly to stop holistic thinking and to employ scientific reductionism in its place.)

But for the moment I want to consider something small scale: employing the vocabulary and tools of permaculture to specific tasks in a garden. Here are the stated principles of permaculture:

  1. Observe and interact: By taking time to engage with nature we can design solutions that suit our particular situation.
  2. Catch and store energy: By developing systems that collect resources at peak abundance, we can use them in times of need.
  3. Obtain a yield: Ensure that you are getting truly useful rewards as part of the work that you are doing.
  4. Apply self-regulation and accept feedback: We need to discourage inappropriate activity to ensure that systems can continue to function well.
  5. Use and value renewable resources and services: Make the best use of nature’s abundance to reduce our consumptive behavior and dependence on non-renewable resources.
  6. Produce no waste: By valuing and making use of all the resources that are available to us, nothing goes to waste.
  7. Design from patterns to details: By stepping back, we can observe patterns in nature and society. These can form the backbone of our designs, with the details filled in as we go.
  8. Integrate rather than segregate: By putting the right things in the right place, relationships develop between those things and they work together to support each other.
  9. Use small and slow solutions: Small and slow systems are easier to maintain than big ones, making better use of local resources and producing more sustainable outcomes.
  10. Use and value diversity: Diversity reduces vulnerability to a variety of threats and takes advantage of the unique nature of the environment in which it resides.
  11. Use edges and value the marginal: The interface between things is where the most interesting events take place. These are often the most valuable, diverse and productive elements in the system.
  12. Creatively use and respond to change: We can have a positive impact on inevitable change by carefully observing, and then intervening at the right time.

I don’t know about you, but while I agree with this list, it’s all a little vague. And so what I’d like to look at is specific techniques that have broadly become part of the permaculture bag of tricks that somewhat adhere to this thinking.

To make the goal concrete, let’s focus on one question: how can a gardener create different sorts of microclimates of soil, air, and water for the diversity of plants one might want to include in a garden? While I could have considered other goals like water purification, fertilization, composting, water transport, etc. I’ve found myself trying to figure out microclimates a lot lately so it seems like a good place to start. It seems to me that many challenges I’ve run into while gardening have to do with the environment not being right for what I’m trying to grow, something that’s inevitable given that most of the food-bearing crops we eat today are not native to the places we live.

I’m often reminded of Sepp Holzer’s citrus gardens in the Alps as a sign that it’s possible to do amazing things with microclimates, but very few people have Holzer’s level of skill and experience. This is where programmable permaculture comes in. To make the analogy concrete, here the hardware is permaculture, which is capable of being used to do perform certain actions towards a goal, and the software is the creative combination of instructions for the hardware to achieve that goal. The certain actions the hardware can execute is its instruction set, and usually hardware is relatively minimalist (and the challenge is to make it complete at the same time), so it’s the combination of steps that makes it powerful. In addition to the microclimate aspect we want to adjust (soil, air, water, etc.) there’s the question of scale—how big is the microclimate? Are the techniques that help when building an herb spiral the same as when building an impoundment lake? That is, is there a subroutine in common between the two?

Let’s say we’re trying to grow avocados in a flat garden in a suboptimal climate. Avocados (the tasty cultivars, anyway) require well-drained fertile soil, nearly zero days of frost in the winter and relatively warm summer days, no shallow-root competition, and lots of direct sun. While we’re probably not going to be growing avocados in Portland, Maine (anytime soon, that is), we might be able to grow them in Portland, Oregon with the right microclimate. So let’s decompose it:

Soil: the soil in the Willamette Valley is plenty fertile, though throughout the winter it’s probably too wet for an Avocado tree. Here we might apply the principle of self-regulation, and dig a shallow French drain near the tree, and direct the water from it to a pond. Since the garden is flat in this example, the tree would have to be on a raised bed.

Frost: Portland has over 30 days of frost a year and even a few days with highs below freezing annually. (To give you a sense of the challenge that presents, consider that the California Master Gardener Handbook lists Santa Cruz County as the furthest North one can reliably grow avocados, and Santa Cruz gets something like 3 days of mild frost per year.) Here we clearly want to catch and store energy. The key is that the average (over a 24 hour period) is typically above freezing, and so buffers are key. We want to store a lot of heat and release it slowly, and conveniently water has the highest specific heat capacity of any common substance. That suggests that digging a pond near the tree—perhaps the same pond that was used for drainage—would help store heat during the day and re-radiate it at night. Add warm wastewater from a house to the pond and we apply the principle “produce no waste” while giving the tree-pond system a margin of safety for those days that don’t go above freezing. Stones placed in and around the tree and pond can add to the pond’s heat buffering.

Sun: The Pacific Northwest isn’t known for its sunshine. It’s likely that the directly incident rays in Portland would be insufficient for a tropical / sub-tropical tree like an avocado. Conveniently, water reflects light, and by placing the pond at the correct angle for the winter sun, we can provide a bit of extra sunshine to the tree via pond reflection. But what if the sky is just gray and the sun’s rays diffuse? While there isn’t much we can do, we can build a small parabolic reflector that redirects the sun’s rays at the tree from another spot in the garden. (One technique I’ve heard of is to pick up a discarded satellite dish and cover it in something reflective like aluminum foil.)

The other microclimate needs—such as warm summer days—are probably already met here.

While this application of principles was fun, it wasn’t as, well, programmable as I would have liked. Ideally it’d be possible to take a setting, describe the constraints / objectives within some dimensions, and then directly apply techniques that are derived from the principles to achieve the goal. In another post I’ll try to develop what we might consider an instruction set for permaculture and also, separately, what might differentiate permaculture from geoengineering.

Barath Raghavan

Barath Raghavan is a computer scientist who writes about the intersection of energy, environmental, and technological issues.

Tags: microclimates, permaculture, permaculture principles