Monday, January 28, 2013

Industrial Gardening - High Tunnels

Being my normal curmudgeon self.

Industrial Gardening

High tunnels are extensions of the fossil fuel supply line.  The plastic covering requires barrels of petroleum and therms of natural gas for feed stock and the energy to manufacture.  The support structure, whether plastic, aluminum or steel, requiring energy for manufacture and energy for mining in the cases of aluminum and steel.   All require transportation and auxillary energy for storage and installation.

High tunnels are industrial gardening.  They are not sustainable, they are not green, they are not environmentally safe.
“Polyethylene covers on high tunnels and greenhouses make a significant contribution to the growing problem of waste plastics.   .  .  . Most of these plastic films are produced from low-density polyethylene (LDPE #4) resins.”

For a round style high tunnel – 20’ wide x 12’ high x 48’ long – it takes approximately 50 ft of 40 ft wide of 6 mil, 4 year plastic.
Email quote from Kenneth A. Erha
E-Commerce Sales Specialist, Engineering Services & Products Company for,,, and
This weighs approximately 56 pounds.  From data at Plastics Europe this can be figured to be at least a couple of barrels of crude oil every four years.

It is important to understand that high tunnels do not offer a sustainable alternative in a world where access to oil and natural gas are requiring more and more energy to extract.  In a world where obtaining fossil fuels requires more and more environmentally dangerous practices; coal included with the removal of mountain tops.  This does not even consider the carbon and other greenhouse gas emission required for the materials, manufacture, transportation and installation of high tunnels.

My point is not to negate the use of high tunnels as much to require honesty in the promotion of them.

High tunnels as industrial gardening is not a sustainable answer to our food needs.  It is a side ways move to business as usual.


  1. As a high-tunnel user, I want to defend an evolutionary approach.

    Can any of us simply jump off the civilization cliff? We'd like to think so, but probably not.

    We grow food for the surrounding community on a small co-op organic farm. We're lucky, in that our community supports local agriculture, but we still must be somewhat competitive with the huge industrial farms.

    So we use a high-tunnel, but eschew planting plastics for soil blocks. We use plastic drip-line in the greenhouse, while using plastic-free gravity-fed swale irrigation in the fields.

    At this stage, I think it's better to be moving toward a goal than to jump right into it and lose your shirt, no?

    1. Susan - My goal in writing the high-tunnel essay was only to point it out as at best transitional. I have dear friends who have a high tunnel, have also a huge garden and make some of their money from selling their food. At dinner, they told me they had discussed exactly what I noted in the essay. I wish you and your family the best.