When I started developing my vegetable garden I had little biomass handy for various projects beyond a modest stream of goat manure. Gradually support species established, and now I have more than I can use. One especially valuable plant is bamboo, which I am steadily learning to use for various projects. Today I made a bamboo trellis using zero string or fastening.

A typical approach for growing climbing crops in this industrial age is to put in a few star pickets (T-posts in the USA) then string some wire mesh between them. Then when the crop is finished you face the horrible job of taking the rusting, tendril infested mess down again (or leaving it until it becomes a hazard).

What most people never stop to consider in this time of overabundance is the resource consumption of that simple construction. The early industrial revolution was primarily a transformation in the production of iron- that essential ingredient in civilised life for thousands of years. Up until that point vast amounts of forest were cut in rotation to make charcoal, essential for smelting iron ore. That made iron so valuable that it could only be used for hand tools, weapons and fasteners. The idea of using iron for structural purposes like roofing and fences would seem absurdly extravagant. Tapping into vast coal reserves upended that equilibrium, and the rest is modern history.

One single bed in my vegetable garden is about 10 m long, needing six star pickets and an equivalent length of wire (double if I couldn’t be bothered training the vines up). I would estimate the structure would contain about 40 kg of iron, which has an embodied energy of about 20 megajoules per kilogram, for a total of 800 megajoules of embodied energy…

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