Big Greenhouse Dream
Sometimes it pays to think outside the box and to think totally outrageous and big. This is one of those cases. Will it result in a greenhouse based on the dream? Perhaps, perhaps not. Over time, plans have a habit of changing. However, as one considers these options, new things are learned, horizons are pushed and new ideas are formed.
This is the story of the Big Greenhouse Dream…
My wife really likes it here. I have absolutely no comprehension as to why. People here are nice enough - no personality complaints. However this place is about as far from my preferred environment as I can get. Well, I could get further, but the sentiment is what counts here. I am a tropical person. All the plants I like most are tropical, the weather I prefer is tropical, the lifestyle I prefer is tropical. I don’t remember anything from my two years as an infant on Hawaii - tho I have been obsessed with Hawaii ever since - but my time living on Guam was… it’s beyond description. I felt right. I loath four seasons. I loath the cold. Not much pleases me more than wandering thru the jungles or swimming in the reef or finding a water-hole in the jungle to swim in.
However, I happen to be pretty attached to my wife. She’s attached to her parents and she’s a four-season girl. There’s not much room for compromise. Sure, we could live on Hawaii and she could visit Mauna Loa or Mauna Kea during the winter for some snow action - but it’s not going to happen. So, here we are in cowboy town where exiting fun can involve tipping cattle and riding bulls. Not to slight that - some people to find that fun. Me, fun is jungles.
So, I’m here with a couple of acres of rather inexpensive property in an area that rains little and when it rains it’s at the wrong time of the year for me, that gets very hot during the summer and freezes in the winter just enough to render outdoor tropicals mostly impossible. The plus? A couple of acres of inexpensive property. Oh, and a well. And a wife who realizes my frustration and is allowing me carte blanch on the property.
Part of that carte blanch is my pit greenhouse. Thanks to that little pit - 12′ wide, 8′ deep and about 45′ long - I can grow many of the tropicals without going broke trying to keep it heated. The earth-mass of the pit keeps it acceptable all winter long - it’ll get a bit cool in there with the enclosure I have there now but it never freezes in there. It’s fun, and I’m expanding the cover over the whole pit to grow my collection. But it’s not the jungle I’m looking for. I want a jungle that I can take a few steps into and be lost. Here’s where thinking outside the box comes.
I could expand the pit to 30′ wide and dig it longer - 100′ or so. It’s still an option. I think that’s about the maximum I can dig before I start losing earth-mass benefits. But there’s another option. Build an obnoxiously large greenhouse where the volume of air within becomes heat-mass value - where the ratio between volume and glazing is to a point where the glazing cannot lose heat in the winter nights fast enough to chill the greenhouse too much before the sun comes back up.
My inspiration came from a picture of a Cover-All building. Well - I’ve got a tubing bender and can make one to custom radius - and the webbing isn’t an overwhelming challenge either. Why not building something like that? Cast off the limits - I can fit an 80′ wide greenhouse out there, and if I’m not digging a pit, I can cover the entire 300′ span of the property. There’s a half-acre under glass. 40′ tall - a little taller thanks to a footing. With the slight slope, the footing will be 3′ on the high part of the property and perhaps 5-6′ tall on the lower part. Suddenly I’m looking at room for coconut palms, even breadfruit! Room for a real jungle. The current pit can be gunited and filled with 30 thousand gallons of water to be a pond - perhaps even dig a river to another pond to recirculate water.
Cross section of the 80 foot wide greenhouse
With half an acre under glass, the sheer volume of air within will be it’s own heat-sink, not to mention soil within that is far enough from the outer chilled soil that it will also contribute. Solar heat the water in the pond and plank the northern third of the hoop with insulated siding and we may have something that doesn’t need active heating. At least here - winters are mild and I’m only having to accommodate two hands full of freezing nights and perhaps a few freezing days. The biggest challenge will be exhausting excess heat even in the winter. Hmmm, I do a lot of work at home - an office out there would be nice. A little thatch-roof hut? Anything is possible when the borders of the box has been thoroughly breached.
Design ideas - two steel tube hoops with steel-tube webbing between them, spaced at 2 or 4′ intervals, center columns for support, plus angled columns on either side of the center support to give the hoops more rigidity and wind resistance, concrete and rammed earth riser that will keep the greenhouse level - insulated and bermed on the outside to give more separation from the chilled earth outside, corrugated polycarbonate panel glazing, northern third of the hoop covered with siding and insulated to give better winter-winds protection - a little shading in the depth of summer is all that would do and coffee and chocolate should handle that just fine, pex tubing snaked on the ground across the greenhouse for supplemental heat from solar water-heaters, solar-heated pond and waterworks complete with a little waterfall to assist in keeping the interior warm thru the night, extensive venting to keep it cool during the summer, misters to help keep it cool too. The ideas keep coming. I could end up with a 30′ wide pit blessed with some of these ideas - or I may build this monster and be done with it. The future is wide open.
Is this possible? Actually, yes. Likely? Your guess is as good as mine. It won’t be cheap, however it’ll be less expensive than an inexpensive house - and be big enough to put our house inside (no, the wife won’t go for that - I already checked.) However, from exploring this option, even if it doesn’t come to fruition, what I learn thru exploring this will benefit me in the final project.
Stumble it!