Defensive Gardening: Designing to Manage Risk
Updated: Apr 12, 2022
Know Your Threats
Research Prevention, Management, and Mitigation Practices
Integrate into your Design
In my former life as an engineer, one of my strengths was designing software to mitigate and manage the risks associated with online software products, especially security and external threats. My approach to designing landscapes, whether “permaculture-based” or conventional, is the same: risk-based design, or defensive design. It is absolutely critical to your success and sanity. The threats to your orchard, garden, or food stream come from, literally, everywhere: the air, ground, animals, humans, the nursery, bad data, and climate change. At times it can feel like Nature is against you. Don’t take it personally, get to know your threats through experience and inquiry, and prepare for them with a robust design.
I organize threats into several targetable "classes," and I will briefly walk through one class as an example to help you design a garden of excellence.
Risk Class: Fungal and Bacterial
Key Mitigations: Species Selection, Rootstock Selection, Spacing, Diversification
To help illustrate defensive design, let's address the Fungal and Bacterial class of risk, namely Apple Anthracnose, or "bullseye rot," usually caused by the fungus Cryptosporiopsis curvispora prevalent in the Maritime Northwest - see image.
Apple Anthracnose has been devastating in the region to the point where some nurseries, like the Bullock's, stopped selling apple trees to customers...for a while. Well, we all love apples, and our clients, nonetheless, want them in their landscape, so we have to design for that requirement by thinking defensively.
Several strategies are available when designing to mitigate Apple Anthracnose and other fungal and bacterial threats. First, you need to give your apple trees plenty of sunlight and airflow as they mature. Second, you need to select disease resistant species. Third, you need a rootstock that is resistant and appropriate to your local ecology. (I'll add this too, though it doesn't show up on the design: plan to prune defensively and control disease "chemically," if you are in the Maritime Northwest.)
Some apple varieties that are highly susceptible to Apple Anthracnose include Akane, Gala, Melrose, Spartan. (Sad, yes, I love Melrose too.) However, leave these out of design and include more disease resistant varieties, especially Gold Rush on M111 rootstock, which an orchardist friend of mine characterizes as “a force of Nature to reckon with Nature.” Rootstock controls many things about your tree: it's akin to the "brains" of your tree. Rootstocks are not all created equally, and you need to select a rootstock appropriate to your local ecology, personal goals, and of course, risks. In the Maritime Northwest, M111 is an excellent choice, but other good choices are available and in development. M111 is a "standard" sized rootstock, which produces a vigorous (big) tree. That brings us to spacing, which can grant your trees the sunlight and airflow they need to stay healthy. You can’t "hedge row" your apple trees like you may have seen in Eastern Washington orchards. In our ecology, they need plenty of space. Design for it; give it to them and they will perform. In fact, a strategy I like to suggest is to plant one tree and graft different apple varieties on it to get the diversity you want and optimize spacing for health. Lastly, diversity: "diversity is resilience," I am fond of saying. Unless you are a commercial producer, you don't need more than one of the same apple variety. In fact, if you build on M111 rootstock, you will have a big, prolific tree that crops early and heavily. Eventually, you may have the "too much fruit" problem. So, diversify, first the species and then the variety. Remember the Irish potato famine? Diversify!
Obviously, the key to being successful with defensive design is knowing your threats. One of my colleagues in the tech industry enjoyed saying, “If you’ve got time to do it twice, you’ve got time to do it right the first time.” It is a truth of permaculture design too. You want to avoid false starts, digging trees out and moving them, moving your garden, and so on. I’ve seen it a hundred times. It’s costly and frustrating. Design defensively.
In the next blog I’ll discuss more about defensive design using voles as an example, and how you are probably giving them just what they need to thrive in your garden. Design to make your garden inhospitable to them.
Get in touch with me if you want help designing your food scape. Thank you for reading. Happy gardening.
Make excellence a habit, not an act.