Hoop House Permaculture Brainstorm: Input Welcome!

Many readers will know that I am a Big Fan of Hoop Houses (aka High Tunnels) as low cost, easily erected, functional structures.   Last Spring I was part of a group that submitted a grant proposal chasing some of the Stimulus Money.  Obviously we failed (should have said we were expanding an interstate), but the idea of a structure producing, food, fuel, and resources in a linked system has lived on.   While I spent much of the early Fall leaning strongly towards re-committing to perfecting the small scale agriculture / Suburban Permaculture model here at the Home Site, the last 2 months have given me cause to rethink that; I am more convinced daily that The Funnel is closing faster than I had let myself believe and it is time to Get Busy.

So here is my challenge to all of you: Help me design a permaculture system within a 30′ wide x 70’long  x 12′ high Hoop House and I will pitch it for funding.

Here is the design criteria:

  • Produces Food
  • Produces Fuel
  • Produces Resources
  • Is self sustaining in terms of funding – we want sale-able products valued at least $10k annually (money being a convenient current measure of “surplus” goods and productivity)
  • Use of only local inputs acquired on farm, or within community.
  • Productive in Year #1, though system should “progress” with time as systems mature.

30x70x12 Hoop House - Insert Permaculture Here...

Short List of Resources available:

  • 30x70x12 Hoop house
  • Space Heat (a bit over freezing in the winter) and Warm Water from a Biomass Gasifier
  • Electricity (grid for now, gasifier generated soon)
  • up to 20-30 hours of weekly labor year round, 10 preferred
  • Start-up Expenses up to $20,000 (Structure $5k)
  • Small Scale Ag equipment (seed starts, tillers, seeders)

Potential Inputs:

  • 20 acre farm with 5 acres tillable – straw, ethanol / BD feed stocks, unsaleable vegetables.
  • Manure from livestock
  • Community Waste streams such as yard leaves, food waste, etc

Examples for inspiration:

To these we would like to add energy systems such as small scale biodiesel, ethanol, and / or methane to further increase efficiencies, reduce waste and increase outputs.  Example, tilapia carcasses could be used as a methane feedstock while the digester itself adds to the thermal mass of the Hoop House reducing night time heating load and the methane burned in a generator to produce supplemental heat and electricity for pumps and grow lights or power other farm buildings.

The overriding focus is to design a system with elegant energy flows mimicking an ecosystem in true Permaculture form.  We wish to use natural biological systems whenever possible rather than mechanical solutions.  Technology will be very evident, but used appropriately only when natural systems are not feasible.  For example, beets don’t turn themselves into ethanol without help, but Tilapia will happily breed new young if provided a proper habitat and their water filtered readily by plants such as watercress rather than industrial nitrogen filters if stocking rates are reasonable.

I envision much of the structure to house known systems generating sale-able goods such as extending the growing season per Elliot Coleman or Growing Power style vermiculture.  And these “profit” systems will interweave with experimental ones such as a self propagating, natural filtered Tilapia aquaponic system using both male/female fish fed with on farm products.

But that is the rub – its a “vision” right now.  There are hundreds of GREAT minds that read this blog – please comment with your musings, link to your inspirations, and help spur this project to something unprecedented to push the envelop of our sustainable culture.

If the conversation gets going I would like to form a Google Group to facilitate the uploading of documents and links.  Here is a link to a shared Google Doc on a 30×70 grid to help with layouts should anyone really want to jump in.

Be the Change!!


63 Responses

  1. Which way is the hoop house oriented?

    • Long Axis runs North South – from what I have read, above the 40th parallel the more that is important – it limits the exposure to north winds. But more significant for this site, we will be attaching it to an existing structure that is on a N/S axis.

  2. Another dumb question – dirt floor?

    • yes – very high grade soil with a sandy loam structure. Posts/small sections of concrete foundation are certainly possible if justified.

      Also, I should mention that the current front running structure is single film heavy poly for about $5500. A double layer film with a blower is available for another $3000 in up front costs, but designs will need to justify that extra cost.

  3. Rob, this is awesome, both the idea and the open source approach to planning.

    I don’t know if I would try to make it produce much of its own energy. This is zone one intensively managed space; it is OK to draw energy from woodland that is less managed. There is a fine line between building an ecosystem and constructing a biological Rube Goldburg apparatus.

    I’m not sure tilapia carcasses are the ideal feedstock for a methane digester. The fish guts are pretty high on the food chain and a lot of nutrients and energy would be lost dumping them straight to the bottom. I would grind them up and feed them to chickens, then use chicken manure in the digester. I’m not sure how chickens would handle eating ground fish bones, but they are capable of regulating their calcium intake if they have another food source. I’ve found that chickens can’t peck through the scales of a goldfish, but they are very happy to pick meat out of the bones and scales of a raw fish. Or, if you don’t need the tilapia for energy, you could feed them to black soldier flies, then feed the larvae to the fish.

    I know y’all are worried about asian carp taking over the Great Lakes. But they would be the ideal fish for cold climate aquaculture, except for the extra bones.

    Rob, knowing about “the funnel” is a big emotional burden. Take some time off, have a drink and a smoke, don’t burn yourself out. We’re living at the peak of human creativity and consumption, enjoy a little of the party. There will be plenty of time to miss it when it is over.

    • Matt – great thoughts!

      To be clear, we are not *producing* all the feedstocks in the hoop house, merely tapping into the energy flows for the processing – we will have a gasifier on site producing energy (burning waste wood from the property) that can be used to heat an ethanol still, warm a digester, or process BD. The waste heat, and in some cases CO2, from those endeavors would be beneficial to the growing space. As producing energy needs some oversight it is a Zone 1-2 in my mind and my thinking is that I might as well be harvesting watercress, weeding claytonia and feeding fish while I check still temperatures hourly. Most of these machines take up relatively little space at the size we are considering – at least compared to 2500 gallons of fish tanks or 1000 sq ft of beds.

      I like you thoughts on the fish carcasses – “food” for thought there!

      Your thoughts on time / energy management are well placed. I currently have 4 days off, the goal is one day for rest and reflection, one day at my home gardens to push Suburban Permaculture, and 2 at the Market Gardens. Most importantly, this structure would be cooperatively run with 1-3 other key stakeholders and likely more volunteers. There is a core group that feels passionately that a system like this needs to be built to provide working models for others as we begin down the Long Emergency. Without that group I would never consider something so ambitious.

      Thanks Matt- keep it coming!


  4. Rob, this is awesomely impressive. Not ever having had a hoop house, I have no experience on which to base any suggestions. But am I going to let that stop me running my mouth? Of course not. A couple of ideas…

    Harvey Ussery showed pictures of his hoop house in winter at last year’s PASA conference. At one end of the house he had a little worm farm and winter quarters for his hens. The worm farm was a deep pit formed with poured concrete, but the bottom left open to native soil at a certain depth. The hens were on the other side of the door on deep litter, also open to native soil. The worms were abundant enough to supplement the hens’ diet. The hens built excellent mulch on their deep bedding, and also contributed a small amount of warmth to the house while conserving their own energy, protected from the extreme weather outside. Each hen required 4 square feet of 12″ deep bedding in order for the bedding not to become fouled. Contact with native soil was also necessary so that microbes could help digest the manure.

    Secondly, an idea I’m working on myself. We’re going to have a passive solar array put in to provide heat for our home. A heat shunt is required for this system, to prevent over heating. Not much of an issue in winter. But in the “shoulder” months – when we don’t really need to heat the house much (late April, May, September, early October) – that heat would be a boon for season extension. So we’re having the heat shunt run just where a small greenhouse or hoop house would fit on our property. The shunt will heat the soil, though by how much we don’t yet know. During high summer the shunted heat probably won’t be of too much use, except maybe for peppers. We’ll see. Inside we may also be able to use the top of the heated water reservoir as a place to start seeds. Again, we’ll see…

    Don’t know how much use this idea might be for you, but I thought I’d mention it as a doubling-up concept.

    • Chickens are an idea that I have been toying with as well – Will @ Growing Power has broilers in one of his hoop houses – but it is dedicated to them. Especially if we go to something along the lines of Matt’s idea it would be nice to have them closer. And I love the idea of using them as tractors to freshen the soils in the growing beds. I feel that I would never get the diesel smell out of the structure if I run the Grillo in there much (another reason to start making BD –my source dried up). Using them as a pre-shredder for raw materials has advantages too, and beats me buying a $1200 shredder for the Grillo. Hmmm.

      Soil heating is something I have heard about, but may be less important in a 30′ wide structure – if we insulate the ends (deep mulch of leaves) it is unlikely we will get any frost at all. That said, higher temps would greatly increase soil microbial activity. Perhaps we run temporary line (garden hose) through a bed to compare growth rates.

      Great ideas- keep em coming!


  5. Thought I would add another data point to Kate’s ideas about chickens and worms. I keep my hens in a pen with 20 square feet per chicken. If the mulch is more than 12″ deep, the worms are able to hide from the chickens and build a huge population. Even though i have only five chickens, the mulch sometimes gets warm enough to steam in the cool air when I turn it with a pitchfork. I’ve also buried some logs under the mulch- I dare some termites to get in.

    Wheat straw is composted in two months, but retains just a few hollow spaces to allow air in. Wood chips last longer than six months in the pen, but break down quickly when applied to soil. I think pillbugs are responsible for breaking woodchips down after they leave the chicken pen.

    The chickens accelerate the bacterial processes of decay, but they prevent mycelial nets from forming and constantly scour the mulch for bugs. When the material leaves the chicken pen, the processes that were held back acclerate.

    I see my chickens as a grain powered compost shredder, which produces eggs and meat as a byproduct.

    • Just added a 150 sq ft EGCS unit (Egg Generating Compost Shredder) to the draft layout….

      We’ve been talking about letting the small grains we use in our cover crops set seed, then harvesting the stalks + grain and feeding them to the hens. Gene Logdson advises this and has always sounded like a good idea. Also, by waiting until the plants die, most water soluble nutrients stay in the soil. Root mass builds humus, and nutrients lost to straw and grain are reapplied to the field after being run through the EGCS.

  6. 1. Think about rabbits in slatted housing to provide meat and natural output.

    2. How about collecting the rainwater from this enormous structure?

    3. Balance of companion/diversity planting plus plants which will attract beneficial insects.

    4. Quail have been used in tunnels with some beneficial effect, I believe.

    Good luck with your venture. Please let us know how it goes.

    • Thank John!

      1) – My wife is near-vegan which puts a damper on killing cute furry things, but this is a great option for others. Even keeping them for fiber / manure may work
      2) Great idea!
      3)I am struggling with this one – we are essentially in a bubble, but depending on the unit we get roll up sides may allow insects in and flowering plants would be critical to enticing pollinators.
      4) Quail! Yep… UK IP address! It would certainly make us a niche grower and could add significantly to the profit line.

  7. My ideas:

    Somewhat complicated walls, insulated and a source of energy as well as a huge thermal mass. Strawbales draped in plastic, with earth piled on the outside, and a hugelkultur bed on the inside. The hugelkultur bed will be built from the waste streams of arborists and construction projects. The plastic wrapping the straw bales can potentially be waste HDPE film from grocery bags etc. fused together with moderate heat (the tutorial here apparently misses the opportunity to overlap bags before fusing them); I’ve also this sort of construction is more durable when two plastic layers have several layers of newsprint between them.

    Additional raised bed(s) at the same height as the walls (or higher) can be built in the interior so that only narrow paths exist between beds, but the plants are all elevated above the paths to an ergonomic height, and the coldest air in the structure is allowed to fall well below the foliage.

    The entire hoop house could slope toward the south to give it more sun: sloping paths would channel cold air into a hot compost pile at the south end, which would then heat, moisten, and carbonate the air and send it up the slope of the plastic roof to the north end of the structure. The beds might, of course, slope more than the paths or roof, as long as the work could be kept between knee height and shoulder height.

    A three-layer film around the greenhouse would help retain heat. The outer layer would be relatively pricy stuff, UV resistant etc. The middle layer would be bubble wrap, with slits in it to expand like a net, cf. expanded metal. It would take a little time with a well-designed jig to slit the bubble wrap properly, but it would end up a simpler, more-robust, and better-insulating system than a fan pressurizing the air between the layers. The inner layer can be cheaper stuff, low-mil drop cloth perhaps.

    Over-termperature protection could be by convection-driven heat exchangers, controlled by magnetic curie valves, which operate completely automatically and harvest all the energy they need to operate.

    • A few continued thoughts:

      The beds might need to be stabilized somehow. I think edging them with some sort of deep-rooted, long-lived, and well-behaved vegetation might be enough. Maybe vetiver?

      Also, 12 or 15 foot high north wall might be built of straw bales, to support cables that slope down to the south, replacing most if not all purlins. This would allow marginally more light, and perhaps a lower-cost structure. Ideally, the wall would lean north a little bit, and the cables would continue over the wall and extend down at a steeper slope on the north side, to balance forces.

      • Joel suggests Vetiver as a deep rooted, well behaved plant to bind soil. Liriope is great for this; the roots are only five inches deep, but they form a strong, tangled net. A rototiller doesn’t stand a chance of cutting through it. And it is widely available.

        On a hillside, liriope planted on contour will catch all eroding soil and resist a torrent of water.

      • Thanks! I would not have thought of liriope, but it sounds like it works in similar circumstances.

  8. Oh! I forgot to mention the other cool hoophouse thing I’ve seen. You’ve probably seen it too. I think it was Steve Moore to came up with it. Sort of gutter-planters hanging from the hoophouse purlins. He might have originally used sliced open pvc pipe, maybe 6″ or 8″ in diameter, to hold soil for shallow rooted and/or trailing plants. Can’t remember exactly which crops he put in them. These could run the entire length of the house under each purlin and provide a bit more real estate inside. Ideally, they’d hang low enough to make tending them not a complete PITA, but not so low that they’d be an impediment either. Guess you’d need to work out drip lines for them too. But any real estate in a hoophouse is valuable. Maybe by now he’s come up with something less toxic than pvc to use.

    • I’ve seen some clever designs using actual rain gutters.

      I wonder how easy it would be to channel condensation from the plastic down the supports and then to the plants.

  9. The overhead support structure could provide and opportunity to drop twine, wire, etc for the purposes of vertical growing. There are issues of shading to consider, but from a crop hygiene standpoint it might prove useful given that most four season hoop houses I’ve been in are prone to excessive moisture. It could potentially allow your plants a higher tolerance for dampness, and lower the need to open vents (eliminating the side effect of lowering the temps.)

    Back of the napkin idea of course, I have no Idea how it would work in the real world.

    I really like Joel’s design, my only addition would be some manner of raised water storage on the north wall (painted black for thermal absorption of course)

  10. A random thought on fish food- tilapia would probably eat grass clippings. I’ve seen grass carp that know the sound of a weedeater. They follow my friend around the pond when he trims the grass, gobbling it up. I don’t think it makes sense to plant a “fish pasture’ inside a hoop house, but grass could be an cheap, low maintenance food source when it is in season.

  11. I think that the tilapia idea is certainly better than beets, as you stated. However, i would agree with Matt W above in that if you are looking to create cellulosic ethanol, there is a lot of organic matter like switch grass and wood chips, not to mention many other high carbon types of waste, that can be used for this process. Ethanol plant design has recently been a major recipient of federal and state grants, so I wouldn’t be surprised if you were able to receive some of this funding if you are doing R&D for Cellulosic ethanol production.

  12. Add to your reading list (if you haven’t seen it already) Solviva: How to grow $500,000 on one acre, and peace on earth. See also http://www.solviva.com/ . Their greenhouse is mostly chicken- and rabbit-heated, with some water for thermal mass and lots of vertical growing.

    • Emily,

      Its been on my Amazon wish list for well over a year and was on my Christmas list (along with a Ferrari Cobram 40AR…) this year. As this goes forward it is moving to a “must have”. Thanks – and welcome back.

  13. I think you need to pick your critters first and build around them – rabbits, chickens, tilapia, quail, worms (well I guess you don’t need to build around worms so much).

    Seems like chickens or quail have the advantage of providing protein without so much “processing” as the rabbits or fish. But the next question I’m thinking about is if any combinations of animals can benefit each other. I just don’t know enough about the fish or the rabbits to say though. If you had chickens, you might want to seriously consider having an outdoor “run” for them connected to the greenhouse. Let them do some of their own harvesting outside, and expand the carrying capacity of the system.

    Wait, I remember reading about chicken manure as a pond additive for raising tilapia, which sounds weird… but I did find the link:

    Another thought would be to take the approach of providing a nutritionally balanced food output. Rather than focusing on maximizing dollar value, maybe maximize nutritional value and sell it as a package, either CSA-style, or to local restaurants. Grow ingredients with cooking in mind, or at least ingredients that go well together.

    I don’t have specific ideas for hoophouse layout/design yet. Too many variables in my head…

    • There is wisdom here – livestock seems to be landing on worms and perhaps chickens year 1, then add tilapia as energy system is figured out.

      Markets will drive crop selection in year one – funding is coming in, but will fall short of our Year 2-3 goals and we are striving for self funding.

      The “nutrition” CSA is a great idea! My wife is a amateur nutritionist (what near vegan isn’t?) and would love setting that up.

      Chicken manure is being used to charge the man made pond ecosystems – my understanding of our intense aquaculture systems such as Growing Power is that they are in nutrient excess due to their stocking rates nearing 1# of fish per gallon at harvest weight.

  14. Spent the afternoon with the Farm Owner – what he is focusing on is how to link biological and energy systems, in this case a 500 cu ft flow through methane digester running in a pool of rather warm water down the middle of the system. Imagine the growing possibilities with that much thermal mass (about 5000 gallons) at 101 degrees in your green house!

    Here is an example: follow the energy flow from Gasifier powered Hot Water Heat Sink (140 degrees) to regulate methane digester (101 degrees) then that is used to regulate the Tilapia tanks (80 degrees) and worm bins (75 degrees) and finally running throw surface hoses under external cold frames (end temp of 45 degrees) where it runs through our Gasifier Cooling tower before cycling back into the syngas powered Hot Water Boiler to be reheated and sent to the Heat Sink (140 degrees). Rinse and Repeat.

    Gasifier is powered by coppice planted willows planted as polyculture hedgerows (1.5 acres needed by my math with .5 acre harvested annually – 2 acres needed if trees grow slower) which are chipped and burned for syngas. End carbon products are 50% CO2 to air (may be used to charge growing systems, but would kill any chickens so outside runs are needed) and 50% biochar which is then added back into system as water filters and soil amendments to sequester 5 tons carbon annually. See my CSE post for details

    If we can pull this system off it will provide the convergence and fulfillment of about 75% of the posts and dreams of this blog. All that will be left will be my articulating, bidirectional italian tractor…


  15. “This site is dedicated to the skills and philosophy for more self-reliant living. Whether you have access to fifty acres or only a patio pot, you have the opportunity to produce more of your own food for yourself and your family, to enter more fully into the yearly cycle, and to know your place in the web of life.”
    Lots of great info here:

  16. My friends in Manley Hot Springs Alaska built a house with a roof, brick front and one side. The back of the house and one side had two layers of heavy plastic attached to a wood frame. The water from the hot springs was channeled under the house for heat. In really cold temperatures they had a wood stove just in case, but it was rarely used. Tropical plants, trees, and amazing food produce grew in great abundance. They never went to the store for fresh vegetables. They had lived like that with the same plastic for 25 years when I last saw them. It was always warm as toast inside.
    Best always, Sandra

  17. Here are a few thoughts based on 3 years of our experiences. We grow greens and micros for restaurants primarily but we can sell them anywhere. We never have enough. We converted an old dairy barn to a greenhouse with twinwall poly and made gowing beds on top of the old stalls. Total floor area isn’t too far off from what you have. The BIG difference is we have a concrete floor from the old barn. Leaves around the outside of the greenhouse won’t keep in warm, you have to go down a couple of feet with insulation to keep the frost from migrating into the growing space. Coldest temp yet has been 11 below outside and under a double layer we went down to 24 degrees. At that temp everything was fine. Biggest problem this time of year is light. We tried tilting the beds like Coleman said or using reflection like Solviva talks about, but from now until the middle of February growth is very slow. Next year we will try some of the shade tolerant plants that we are learning about from the forestag folks, the thinking being that some of these low light varieties might do well. For some extra money and using a permaculture mindset, we grow micros, in a mix of vermiculite and compost. After we cut them we feed what’s left to the chickens that are in the greenhouse. They love it. In the middle of the winter we can still get eggs with a brilliant yellow yoke.
    For heating the beds we were great followers of Jean Pain, but we first experiment with hot water pipes from an electric water heater, and didn’t get great results, though the problem might be the set up.
    We have lots of improvements to make but we know the system works. We can gross 20K with the greenhouse and 2,500 square feet outside. We do not heat the greenhouse with anything at this point.
    We use hugelkultur outside in some growing beds we are working on (2,000 square feet), and the initital results are excellent, but I don’t know how you would do that in a greenhouse.
    We have alot of pictures on our blog which show what we are doing.


    Good luck,


    Live Simply So Others Can Simply Live

    • Rob, one other thing on the willows, I found some good stuff in UK. The article I read said you can get 10-15 tons of drywood per hectar per year. Varieties recommended were Vimalis, Chinese, Dasyclados, and Q83. So far I can’t find these stateside. We were looking at Intalian Alder which grows incredible fast, but only hardy to zone 6. Might have to settle for Speckled Alder.

      This guy’s pretty smart when it comes to willows. He’s an adviser at Ragman’s Lane Farm



      Live Simply So Others Can Simply Live

      • Thanks Ed – sounds like you have a really interesting operation going on with alot of corollaries and I will be sure to check out your blog this week. I have been using 1 tons /acre/yr in my figures as I believe our winters to be harder than the UK and am not sure which species will produce the best. Mark Shepard in Viola, WI has both hybrid willow rods and hybrid popular rods for sale (http://www.forestag.com/) which would be good candidates. A side business could be made cleaning out woodlots of buckthorn and “junk” trees” if one had the time and a trailer mounted chipper – then you would be paid for your raw materials.

        Thanks for the links and thoughts!

  18. Hi Rob,

    Can you let us know a little bit more of the other part of your venture ? the sales part.

    I do understand that you will be selling at a farmers market during the summer but what about the other 7 months of the year ?

    I know that you are selling a lot of potatoes to local restaurants, I bet they will be eager to serve fresh local veggie year round. Have you talk to some of them to see if they will be interested ? And which kind of products they will be looking for ? Greens for sure but what else ?

    Concerning the rabbit, I am not sure that will be a low input low time venture, I have a few meat rabbit at home, 4 does, 2 bucks and the meat pens, that already take me some times twice daily to feed them and also once a week to clean out the pens. I produce all my hay (scythe, rake and arms), root veggie, but I do still needs 20 % of their feed to come from the store in the forms of pellets for the does. In top of that they are not that cherish by American. I am french and used to leave in Madison. I loved rabbit meat and pate, but could not find anything in store, so I start to get my own on our back porch, not sure that less than 50 miles south of Madison there is a market for them, but maybe there is a niche to carve hopefully. On the other hand you will have an awesome supply of manure that can be use directly on the ground.

    Concerning the chicken tractor… go for it, I use mine to till my no till garden, they get the bug compost the leaves and get me one of the best garden I ever had ….

    I hope your new schedule is not to hard on you and your family, I ‘ve just switched to 4 12 hours shift one week to 3 hours schift the next week and boy that is killing me and my wife who is struggling most of the time with our 10 months old twins.

    One crop that you might want to look into is belgian endive, they retail for $10/lbs here in our small co op in Mn and are trucked all the way from California and nobody in the small comunity of market growers grew them. at 20 pounds a week bought at $5 by the coop there is room for them to supplement their income during the winter without much work (they basicly grow like beets, seed them, thin them weed them one or twice and your good until autumn when you dug them up and replant them in a frost free dark place to enjoy greens (well yellow) for all the winter months… maybe you too.

    I will think a little bit more to your problem that is in fact our problem, I tried to be as sustainble as possible but with only two arms I tae small steps at a time.

    Hpe to see some good ideas in here to apply myself.

    • Xavier,

      I have reached out to my restaurant contacts and will not be scaling up with out more market lined up. We are small enough that I let my established buyers drive my offerings – they get my seed catalogs Jan week 1 and we meet a week later to talk through pricing, timing, and volumes. Because we are so small, farmers markets are a time drain – we made $2-300 on potatoes a week, but that was with 6-8 hours of prep time just for marketing, vs. 1 on restaurants. With my weekends tied up restaurants, and grocers to a much smaller extent (lower price) will be my mainstay. I intend to grow thousands of pounds for storage crops and there are 2 new winter markets in the area and dozens of Slow Food Chefs in Milwaukee and Madison I am reaching out to. The “storage” crop idea was actually the first thing my best customer asked of me 2 years ago: “… what I really need is onions in January!” On farm sales will be a part too as we continue to do tours and workshops, but that will be very small. We will also be meeting with many of the local growers in the area this January to loosely coordinate the season – make not everyone is growing the same things at the same time. I hope to get some marketing time bartered in there – last year I traded potatoes to fill CSA boxes for his selling some produce on consignment.

      The schedule is working out, and will be hopefully temporary – no more than 2 years.

      I will look into Endive – the greenhouse crop ideas will be my next major research step once I have talked more with my markets. So far both my major clients have been very enthusiastic about extending the season which is encouraging.


      • This is fun. I think we tend to get into a rut when we farm for a living since there are so many things that need to be done on a day to day basis, that innovation tends to fall by the wayside. We have blogged for years at New Farm, but kind of set things aside as we ground into the day to day. Thanks for rattling the cage. We intend to redesign our greenhouse in 2 years so getting back into this will be a big help.

        We have a very strong interest in using some of the techniques developed by Jean Pain. Recently we found a video at


        which showed how they constructed their compost heating system. Mother Earth replicated this system years ago, and then went no where with it. Problems as we saw it were south of France and NC are not Wisconsin or Upstate NY. Also our plumber told us if we were to circulate the water we would have to all sorts of expensive equipment to get the air out of they system. We don’t like expensive nor do we like alot of machinery. About a year ago we ran across an article on the internet about a greenhouse grower that was using compost to heat her greenhouse on the Eastern Shore of Delaware, and she was using a sump pump to circulate the water. Sounded brilliant at the time, but we weren’t focused then so we didn’t dig deeper.

        We have seen people using pool covers to insulate their greenhouses with some pretty good success.

        For greenhouse crops, this time of the year, the only thing growing are the brassicas, bok choy, tatsoi, mizuna, and some kale, chard, and arugula. Everything else has stopped, though deer tongue still does OK.

        It is very frustrating that alot of the in depth research for what we are trying to achieve comes out of the UK which is primarily a zone 5 country. We had been communicating with the lady that did the documentary on BBC, A Farm For The Future, and among other things she suggested looking at what was going on in South Island New Zealand. Similar climate to New England, and a completely different mindset.

        Forestag seems a bit pricey. We have followed their work for a long long time.

        Sorry for the long post.

        Keep beating the drum Rob,



        Live Simply So Others Can Simply Live

  19. For heating/cooling, look into subterranean heating and cooling. Permaculturist and instructor Jerome Osentowskyi at CRMPI (Basalt, CO) runs very large greenhouses at 7200 feet with almost no supplemental heat. Briefly, it works with a network of pipes under the beds, and a vacuum that sucks hot air into the soil during the day, and reverses to blow hot air out of the soil at night. The vacuums can be powered by solar cells.

    Here is a page describing the process:

  20. As always, I vote for “lean and efficient”! Only learn one or two new systems at a time…add more later…

    • 😉 It also REALLY helps with fundraising if we bite this off in $10-20k chunks.

      2010 – greens + worms (known technology), build / install gasifier water heat (experimental)

      2011 – greens+ worms + gasifier heat, then build / install methane digestion / or tilapia

      2012 – greens + worms + gasifier + tilapia or methane, then build the remaining component.

      optional likely additions as time allows – chickens for compost shredding, root cellar off north end, Worm Wigwam “industrial” vermicomposter, Jean Pain hot water composting / methane

      The farm owner has built more than a few digesters so that is less experimental than the tilapia at this point. Using carp, catfish, or perch would be easier still due to broader habitat temp range.

  21. I don’t think anyone has mentioned this yet- a closed system has potential for fungus- how will you circulate air so that blight isn’t an issue? All these other ideas are brilliant and beautiful. Can’t wait to see how it works out.

    • In summer there will be significant air exchange due to the sides being up. In winter Growing Power runs air through almost constantly with big az fans. If we need to do that I would want to put in an air exchanger to save BTU’s. Without the fish tanks my hoop houses run dry most of the time due to limited water (I prefer to run my tomatoes dry to condense flavor… and I’m lazy). The 5000 gallons of fish tanks change that in a huge way.

  22. Hello Rob, Hello Folks,

    I have been reading your blog for almost two years now and you are part of the 4 blogs that I am following.

    Since you posted this entry, I have been lurking around trying to figure out how to make your hoop house a profitable venture … and why not a profitable venture for me, after all your blog is all about getting thinks and more importantly acts.

    As a french native who grew up in the country among farmers and people who suffered from malnutrition during the war, gardening as always been part of my life, from my tiny cold frame where I could grow whatever I wanted ( By the way Rob, I hope your kids have such a place at home) to the big garden of my grandfather to my acre deer proof fenced garden here in Minnesota. For a while now i have been an advocate of the square foot gardening method mixed in with some good old french technique. As a result, I can grow more on less surface during a longer period…

    Since mid December, I have been reading again and again your post. I am not all about permaculture, but I do believe that I kind of grow my garden using permaculture method without trying too so please bear with me if what I am going to propose do not fill the bill, after all you are looking for ideas more than a turn key operation.

    I have seen a lot of people making some good point that you needed animal in your hope house. I have to say that I am all for it but I think that will be an error on your side to have any in year 1 or 2.

    You live 10 miles from your hope house I believe, animals need to be care for twice a day 365 days a year. which means that even if you go 3 times a week to your hope house to tend your crop and enjoy your venture you will still need to go there an extra 18 times a week even in the dead of a snow storm, chicken do not care that you have to plow a foot of snow in your driveway they need fresh water. if someone step in and decide to give you a hand, I bet you will still have to make that round trip a good dozen time just to feed, water and harvest eggs or whatever. this is I believe almost 12 “family” hours wasted for some eggs or meat rabbit, I do not think that this is worth it in term of time and … Out of the farm output. Let a full time farmer do this job, the animals will thank you.

    Now concerning the veggie venture, you will have an amazing chance to grow produce out of season in an area who seems to care for good food, you have there an incredible chance. My mother offered me (and herself) the winter harvest handbook by Eliot Coleman as I want for me and my family more fresh food year round … To be practical, you will have a 70*30 hoop house available in which at the best 75% of the surface will be in fact cultivated so to make your 10k a year you will need to grow $6 per cultivable square foot a year in probably 3 harvest a year. That sounds a lot but this I believe doable especially if you can bring in organically grow veggie in the dead of the Wisconsin winter.

    I have made my own google doc spread sheet, I hope that I will be smart enough to share it with you guys.

    The following info are I believe year 1 of your venture, year 2 and 3 still need to be put down on the paper.

    For me the growing season start in mid September not in spring, as I believe that this is when it all start when you cleaned up your garden and prepared it for the next season so I will start your first growing year in autumn.

    AUTUMN season

    As you might have been able to see in the spread sheet there is 6 growing zone of 3, 4 or 6 feet wide.

    In the first zone, I will saw in mid September a first round of spinach followed by a second round of spinach saw in the growing zone #6. This two zone should give you at least 3 cut of spinach each with a two weeks buff in the between, I bet that you should bring in this $2 per sq-ft without two much problems.

    The growing zone 2 and 3 will be used for what I call the winter soup special mix. Soup should be a staple of the winter table and some root veggie will bring in a good amount of money i believe. Leeks, turnip, onions.

    The growing zone 4 will be entirely devoted to carrots (and radish if there is a market for them)

    The growing zone 5 will be used to grow three rounds of lettuce and beets.

    By the end of February the entire crops should have been harvested. To ease the use of energy, I will personally use row cover.

    SPRING season.

    Once again the need of greens should be enough from your customer to feel up some large part of you hoop house. I will devote the zone 2 to the spinach, using the zone 1 for a mix of beets and lettuce.

    The zone 3 could be use to grow a nice early crop of pea.

    The big zone 4 should be wisely use to grow an early crop of broccoli and cauliflower smartly planted to ensure that a first set of tomatoes and pepper could be put in early may to bring in early tomatoes and peeper in the season.

    The zone 5 should be devoted to carrots.

    The zone 6 to onion, scallions and maybe some leeks.

    SUMMER season.

    Tomatoes, Pepper and squash should filled up all the hoop house for a nice long harvest.

    Now some hanging baskets could be add to grow strawberry from the ceiling those baskets could be used for lettuce as well.

    The two foot wide path between the growing zone 3,4 and 5 could be dug up to install a giant worms bin that will provide probably a good third of the organic matter needed to grow into this hoop house.

    As you have probably found out this is more a sketch than a ready to use orientation, I am personally thinking on how to use my future hoop house for a year round production here in south central Minnesota.

    Have fun with your seeds catalogs folks here I just place my order for chicks and should start my first seedlings pretty soon …


    • So far the sharpest knife in the drawer is


      I was digging in with some of the old permaculture stuff last night, and the story was about using thermosyphoning to move heat from a compost pile or a deep pond into a greenhouse. Anything mechanical bugs the crap out of me, so if I can build a system that doesn’t require moving parts then I am happy. In this case I compost pile like Mr. Bread below the greenhouse and circulate the water by temperature differential would be reall cool. We are definately going to try this.
      Rob, one thing you need to be aware of is that JP rigged his chipper to chip a certain thickness of wood. You are correct it was green, but the gauge was very important. I just bought a chipper for my BCS, and I have enough clever people around me that I may be able to duplicate something similar. There was a company in Canada that was rigging their machines to do something similar, but who knows.
      I was thinking of doing something similar to Finch in Nebraska, by putting in an air to water heat pump above the animals in our back barn but I got hung up because the heat pump companies were telling me, we didn’t have enough volume of air to allow the heat pump to do it’s thing.
      I’ve been a peak oiler for 6 years now, and all the plans we make are with the worst case scenario of no electricity, or gas, or it will be so expensive that we connot afford it. Finch, I think, has the solution, if we have electricity. If not thermosyphon might be the only way.
      We will start another greenhouse this summer dug into a south facing slope. The problem with all of this is, I once figured how much greenhouse space would be required to supply the greens that Tompkins County would need to make it through the winter if we couldn’t depend on CA and the answers was 10 acres.

      Rob this is cool stuff, and there are solutions out there, I know it. It is 12 degrees outside going down to 7 tonight, and we had an amazing salad with dinner tonight from a greenhouse that has no supplemental heat. This is good, this is refreshing.

      Best hopes


      Live Simply So Others Can Simply Live
      in NY

      • Lots of greens can be had by sprouting stored wheat berries/alfalfa seeds/sunflower seeds/etc.

        Very local, very low-input…not very profitable for the farmer, but we’re talking survival of the city, right?

      • I’m replying to my own post which is pretty depressing, but that’s the way it goes sometimes.
        The Oil Drum today had someone post. The post included an article about The Searles Brothers who were big greenhouse growers in Ohio back in the early 1900’s. They had literally acres of greenhouses with concrete floors a steel skeleton and glass skin. And they were one of many. To build a structure like that today would be crazy. Everyone is doing plastic to beat the taxes, and concrete at 100 dollars a yard is also crazy.
        The biggest problem with the compost is turning it with the pipes running through it. We tried to figure some stuff out doing it in our 6000 Square foot back barn and nothing seemed to work.
        I don’t think this is a solution to our post peak food problems, there aren’t enough wood chips out there to make it all viable, but its a start.
        For those of you who live in Colorado and the sun actually comes out this time of year, growing year round is a no brainer. Phase Change Materials our simple and easy. Here in the Ithaca area we haven’t seen the sun for a couple of weeks. Coleman says that if you can keep the soil temp at 50 you can still grow 21 day greens, and don’t worry about how much sun you are getting. This is why we keep searching.
        Joel, we grow micro greens (not sprouts) for restaurants and it is a good business for us. I wouldn’t waste my time with with the wheat or alfalfa. We have pretty decent greens in 10 days using sunflowers, radish, buckwheat, brocolli and some other stupid stuff that just makes it look good. Get your sunflowers and radish seeds from Gourmet Greens in Vermont, and brocolli from Johnny’s. Be very very careful of some others out there that get their seed from China!!
        Rob, I’m volunteering to do research in this area. You are much more organized than I will ever hope to be. It needs to be done.

        Best hopes



        Live Simply So Others Can Simply Live

      • Ed if my understanding of the Jean Pain system is correct – you *don’t* turn it. This certainly means that the systems goes anaerobic at times, but by using larg-ish particle size and soaking the material literally for days he ensured that it should have sufficient air and water for a very long time. “Should” being the operative word. Its worth more experimenting as a supplemental technology.

        I have been looking into chippers for some time and the good ones come with adjustable anvils some even getting down to 5 mm (for composting) and up to 1″ (for gasifiers). They are expensive ($5-10k), but pack in alot of utility and the prospects for supplemental income. I am thinking of pairing a large 6″ log chipper with the smaller shredder for the Grillo giving me the option of shredding the chips with the hammers of the Grillo unit for better composting as well as the option to “hammer mill” food waste for vermiculture use.

        Finches system looks really cool – who wouldn’t want lemons in Zone 4?– but he still needs electricity from somewhere which is why I am so enthralled with the JP methods. Finch has wind (I’ve lived in NE), we really don’t, nor do we have good solar. We have great rains and good soils, meaning stop mowing your lawn here and you have a forest in 10 years. My energy solutions are all biomass focused. Gasification had been my Silver Bullet up until now, but I am coming back to Compost as a heat source – there is very little on farm that I would need more than 140 degree water for. We have the drums in our worm bin up to 105 degrees – that would be making some wicked methane right now. And its 4 degrees out.

        10 acres of greenhouse space in an entire county is very doable. The one I am proposing is .05 acres. Getting 200 of these per county is asking only $1million in startup money and the project has an ROI of 2 years tops.

        I will disagree with you on the woodchips – up here in the northlands, 1.5 acres of short rotation coppice will provide all the energy to produce 40,000 kilowatt hours of electricity with one of our gasifiers – enough for 3 homes or one farm with a workshop. It is not THE solution, but it is a tool to get us there. Combined with PV, Geothermal, Methane, etc, Biomass can really extend our options. Nevada will be heavier on PV, Kansas on Wind, Hawaii on Geothermal and Wisconsin on Biomass. WI has over 16,000,000 acres of woodland and most is used for paper pulp.

        I’ll keep you in mind as the plan takes shape – we should know more within 2 weeks.

  23. Another good resource to check out is the Permaculture Research Institute: Cold Climate. They have research guilds looking into biochar and hoop houses and have just recently started a Google Group for their “growing under cover” project.


  24. Should is the operative word. The problem Mother Earth had was that the system breaks down with the outside temps get too low. JP is in the south of France, how difficult could that be?

    Compost has been my focus for a long time. We cleared the topsoil from an area that was around 2,000 square feet and were going to saturate it with lime which turns the soil to virtual concrete. This would make it easy to get equipment in there any time of the year.

    I’ll read up on what you are doing with your worm bins, that kind of temp with 4 outside is impressive.

    On lemons, our Meyer lemons, that we moved inside are starting to bud out. Very little sunlight and they are still performing.

    I wrote to the energymd who is doing very similar stuff. Lets see if we get something back.

    I’ll keep checking back,

    Best hopes,


    • Hmmmm. Using this article from Mother Earth it looks like they “only” built their pile to 10 or 11 ft wide and 5′ tall. That would only be about 1/8th the mass of the piles Jean was building. I feel the main reason that the piles at Growing Power and Sweet Water do so well is that the are flipping HUGE. Sweetwaters is 14′ tall and easily holds hundreds of yards of waste. At Growing power they are 8′ tll 16′ wide and 80′ long plus they are leaned up against a Hoop House with another pile as big on the other side doubling the thermal mass. Also, ME News saturated the material on the pile, vs. Jean’s soaking them for 2 days. That would be a significant difference in the amount of water available in the center of the piles. In my limited experience pile heat duration is more limited by water than air.

      As you have mentioned the trick is going to be accumulating enough material to build a 50 ton pile. I hope to plant several thousand willows for coppicing over the next 3 years (purchasing about 200 this year and then cutting rods off them for the next several years) which should give me the capability to have closer to that kind of biomass harvestable onsite by 2013. I also have access to several woodlots around here and may offer to clear “junk” trees if I get a chipper this or next year. Still 100,000#’s (wet) of material is a syck amount. I am very intrigued by the near zero embodied energy and net negative carbon footprint of these systems.

      It is unproven in this climate, but so much of Permaculture is. That is were we come in: We are entering the Year of the Tiger – Courage, Hardwork, Openness to Change and Generosity should bring rewards. And I was born a Tiger.

      Its going to be a Good Year.

  25. With the water table so close, it might be worthwhile to dig a well inside the greenhouse, plumbed to a heat exchange grill that interfaces with the air. Cold water running through it during the day would cool & de-humidify greenhouse air while maintaining the high CO2 & O2 concentrations inside. At night, if the air temperature in the greenhouse were below the groundwater temperature, the same effect would heat the air. If two pipes opened at two different heights, and if the plumbing didn’t leach anything toxic into the groundwater, I think the thermosyphon effect could run the system in both modes, and the only control necessary would be a solenoid valve.

    I also had a new idea with similar geometry to the one I drew, except with sharper geometry and with some features copied from the compost-heated hoop house link you posted earlier:

    The outline of each bed built in earth and/or plastic-covered straw bales. Some air vents should be built into them, and maybe some central supports, all of which could whole pallets.

    Compost pits reaching about down to grade in the center of these walls, but not quite reaching to the top. As before, I think it would help the greenhouse as a whole to have the paths slope to feed the compost the coldest air in the greenhouse.

    The growing area would consist of modular planters pushed into straw bales, spanning the space inside the planter and holding a layer of compost exhaust underneath them. Growing medium is placed in holes opened up in these bales, or for very light feeders, sifted into the straw.

    If some bale planters are expected to need less attention for a while, extra bales can span the crenulations, opening up more growing area. Chickens can still scratch bugs from under these, and they can be moved aside on occasions where access to the center is necessary. They won’t get nearly as much heat/ammonia/CO2/moisture from beneath, unfortunately.

    Once a bale degrades past a certain point and has been harvested for the last time, the twine can be cut off it, and it can be spread in the nearby paths as mulch, or mixed into the compost underneath, and replaced with a new one.

    • It also occurs to me that, if some bales are about to be rotated out of the greenhouse, the last planting can include some crops for transplant. After harvesting the rest, the bale can be broken up into flakes, and these flakes slotted into a trench dug by the Berta plow. The trench might not be deep enough to accept the whole flake, but soil and/or mulch can be hilled against whatever projects above grade.

      Here’s an illustration.

  26. […] spinach) and placed my first order for seeds.  The Hoop House (11×25, not the proposed monster Hoopty) soil is still completely frost free, but is wicked dry. I went no till: first scraped the soil […]

  27. I have a single-skinned 30×60 hoop house up and a bigger one on the way here in PA. I would love to raise tilapia and the lemons to squeeze onto ’em! I remember reading some stuff from the New Alchemy Institute when I was researching tilapia a couple of years ago. They were active in the 70’s. I don’t remember anything specific, but I was left with the impression that the man-made ecosystem they created worked, somewhat, sometimes but was very fragile in general. But, I hope you get a workable system in place so I can copy it and order some fish!

    Have you ever heard of anyone using ice for heat in an unheated hoophouse? I was thinking of a system in which water is introduced into the greenhouse, maybe in a gutter or something, allowed to freeze over night, and then somehow evacuated when it’s frozen. I know this wouldn’t be of use to you for your big hoophouse project, but it might be useful in an unheated space. 50 gallons of water taken from 52F to ice releases around 60000 BTUs, mostly due to the phase change.

  28. I know freezing water would in a greenhouse like this would have limited applications, i.e. it would only provide some heat in fairly cold greenhouse conditions, but its free. Even simply filling a line 5 gallon buckets (100) with 32 F water in a 100 foot greenhouse and allowing it to freeze overnight would generate more than a million BTUs of heat. Dolly them outside, flip ’em over, and wait for enough sun to melt enough of the ice that you canslip the buckets off. A lot of work, but would be reasonable in a post-oil world, which is what I’m trying to prepare for.

    I like Ed’s earth tube suggestion way better, but my backhoe has been sans transmission for quite some time now!

  29. For a 100 foot row, not a million btus, more like 600k. Sorry.

  30. For a 100 foot row, not a million btus, more like 600k. But maybe a million generated altogether considering your body heat from that much work, or at least it will seem that way.

  31. Not sure exactly how much this would help, but depending on the floor of your greenhouse, you could have a trench a few feet deep running down the middle. If it was empty it could act as a cold sink and keep warmer air up near the plants, otherwise you could compost in it and the heat would be released up to the plants.
    You could even use vermicomposting, and keep moving down the line where you put food to move the worms. Then the compost on the starting end would be finished and be easy to scoop up and use on plants.
    You could either cover this trench with wood slats or metal grates, maybe have some hot water tubing in it to keep it warm.

  32. Hey Rob:


    I remember reading about this group a long time ago. This is what we aspire to in terms of a greenhouse. PBS had a special on them about a week ago, which jogged my memory. How to do it cheap is the question. Cactus in Wyoming with not auxilary heating.

    Hope you caught the CEO of Petrobas claiming that 2010 is the year. The peak is now. Well 2005, but at least someone with a real job has climbed on board.

    Best hopes


    Live Simply So Others Can Simply Live

    • Insulated north walls and thermal mass are the keys. But Wyoming and much of the Central West gets wicked amounts of sun, as you have mentioned. I went to school in Vermillion, SD and they get as many sunny days in Winter as southern Florida. Thermal mass works soooo much better with near daily recharge.

      We are getting closer to building our structure and will be relying on biomass for heat. Wisconsin has cruddy sun in the winter (2 weeks with one clear day) and spotty wind. Stop mowing your lawn and you get a forest in a few decades. Trees are what we do.

      Didn’t see that about Petrobas, but I’ve been planning as if 2008 had been it…

  33. You might be interested in this project:


  34. There have been shots all around the idea but your hoop house is akin to a ship. Meaning that every square inch is of interior space must serve some purpose or better yet multiple purposes. As has been said-compost pile/heat might be one multiple purpose but perhaps another might be compost pile/heat/mushrooms/earthworms.

    Perhaps building off of the trench concept discussed earlier. Trenched worm bin, inoculated with mushroom spawn where the worms would follow the fresh compost and the mushrooms would follow the worms. Harvey Ussery, a Mother Earth News contriubutor uses this trench concept for worms…the mushroom idea might be able to take advantage of shade and coolness and provide further decomposition of some of the organic matter. Just an idea.

    Another idea which I am experimenting with is co-locating my shiitake logs underneath aquaponics grow bed next to my fish tank along with my worm bin.

    Since the mushroom logs enjoy high humidity, the condensation from the tanks and the shading optimize the environment. The logs can even be soaked and “cleaned” in the fish tank since any insect life is enjoyed as a supplement by my bluegills. (I use a simple solar powered airlift pump so concern about pieces of wood or debris in the water is minimized) Initial efforts using 2008 mushroom logs in my small 12X16 foot backyard greenhouse have been successful.

    Another aspect I try to think about before placement or even building is efficiency and ease of access…again trying to think of the concept as one would if living on a sailboat. A simple thing like placing a water well inside a greenhouse can provide a cooling/heating option, eliminate freeze protection requirements for pumping mechanisms and place the water source close to where it is needed.

    In my simple design, my well will be driven next to my fish tank thereby allowing me to pump directly into the tank by hand and eliminating the need to carry water. As I work with this design I will build an elevated water tank into which I will pump water using solar…from this tank I will water the gardens and trees in my 50X50 foot backyard food production complex of which the greenhouse is one component.

    Now what multiple purposes can I achieve from my elevated water tank…hmmm.

    By the way, love the hoop house interior chicken coop I found at the http://ashevillageinstitute.blogspot.com/ from the previous post…something I want to incorporate into my own hoop house.

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