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pollinator
Posts: 363
Location: NW Pennsylvania Zone 5B bordering on Zone 6
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I got a small 6 x 8 last year. Found it on craigslist. I was lucky enough to get it early enough to be able to start garden plants in it. I started plants for myself, my parents and my cousin. I found that the greenhouse didn't end up being just for the care of the plants. I noticed how much better I felt as I worked in there too. The warmth, the light, the smell of damp soil. It was all very theraputic for me.

I did find that I had a hard time controlling the watering of plants. I work from 7-5 away from home, so there was plenty of times for things to dry out. I tended to worry about them drying out too much and actually ended up overwatering. As time goies on, I will probably add the drip system, but for now I am learning. I also need to get a shad cloth because I almost fried everything a couple of times. Had a couple of casualties, but thankfully not a lot.
 
gardener
Posts: 1352
Location: Cascades of Oregon
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There is a definite learning curve with a greenhouse if they are new to you. But I think they are worth it in my area.
 
Posts: 33
Location: Minnesota
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If I lived up north (been there, done that), I don't think an ordinary greenhouse would be enough for me. I would NEED my own, personal, human sized terrarium! Complete with skylights, a waterfall, indoor pool and greenhouse area for overwintering tropical plants, starting seeds, etc.

Me too.

AND - all that extra summer heat? Seems to me you save it for winter. Greener Shelter, Don ...., is an architect with a technique involving burying it in the ground somehow - oh yes, you just put on a waterproof skirt to keep the ground dry, and it gradually becomes a great heat sink he says. Somebody else stored that heat in the attic, which of course is where it goes naturally anyway.

My greenhouse is going to be at least twice the size of the house it's attached to. (Unless I find some reason to make the house awfully big.)
 
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There may not be hard rules but there are basic physics. Here are my two cents, and yes it is likely only worth two cents.

1. Light has a hard time traveling through evergreens, building, hills, etc. If you need winter light then you will likely want to consider lighting angles and obstructions during the winter solstice, equinox, and summer solstice.

2. A green house, cold frame, hoop tunnel, etc. is generally intended to supply a temperature higher than the normal temperature at the lowest point of the night. So some means to raise temperature must be available be it solar, burning fuel, compost heat, ground water heat pump, etc.

3. Thermal dynamics shows that heat loss from a warm green house to a cold environment is a given. So heat sinks such as black pickle barrels may be desired. Also, plants do not need clear windows when it is dark. So having insolation material to reduce heat loss might not be a bad idea.

4. Systems to trap enough solar heat during winter solstice and coldest part of winter may trap too much heat in good weather. This is why they sell automatic vents and fans. A system must be able to handle both extreme ends of temperature.

5. The greenhouse is a possible solution to a given problem. First truly understand the problem. For example a tree may be able to grow one or two climate zones lower if it can get radiant heat from very large stones, building, or any large mass that can absorb heat. One may be able to start seedling fine just using a cold frame. Certain vegetable like kale may do fine for several months growing in a low hoop tunnel. Remember if all you have is a hammer, everything looks like a nail!!!
 
Posts: 2
Location: US
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paul wheaton wrote:I think that a greenhouse is an excellent idea for about 18% of the greenhouses that exist.  The weird thing is that so many greenhouses strike me as stupid.

Last year I was asked for my advice on a greenhouse location.  These people had dreams of eating veggies in the winter.  I pointed out that the trees to the south were conifers that were so dense that their greenhouse would be in the shade all winter.  They labeled me a "negative nelly" and built their precious greenhouse.  On a bright sunny day in november at about 10:30 in the morning I pointed out how their greenhouse was not only in the shade, but it would be lucky to get 15% of the available direct sunlight throughout the day.  And it would only be worse for the next two months. 

A similar thing a few years back.  With similar outcome. 

I suspect that half of all greenhouses built are built in the winter shade.    And the days are already so short then - blocking even half of the light is gonna make for a really lame crop.

-----

Another thing about greenhouses is that you have split yourself away from the eco system.  By having a greenhouse at all, you are filling in the position of mother nature.  Everything that mother nature does to keep things in balance, you now have to do.  So when fungus or bugs or anything gets out of hand, it is now your job to deal with it.

----

I guess I felt the need to start this thread because everybody knows the upsides (food in winter) but very few people appear to be aware of the downsides.  Deep understanding of the downsides helps to mitigate them or at least decide to not put a lot of money and effort into something that, in the end, won't be worth it.

Just because I may be a negative nelly doesn't mean that these issues are less true. 

Anybody else have greenhouse issues that they would like to warn future greenhouse builders about?






Even there are many problems, we can still find a way to make the greenhouses better.
1, LED growing light for greenhouses in shade.
2, Evaporative pad and fan cooling system can prevent your plants being baked during summer. Also shade system can reduce the greenhouse inside temperature as well.
3, To improve the humidy inside the greenhouse, you can choose fog or mist irrigation system.
 
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This is very interesting. I had envisioned a large greenhouse, and never considered it as not fully permie, but I can see the point. I could eat tree buds and dried apples, instead of tenders, but I would like to have more choices. Besides, even the apples are not entirely natural - I would get improved disease resistant varieties, and have to pull out the oaks/maple/beech to grow them. Remember, poison ivy is entirely natural, and brushing your teeth is not; however, the latter is still a better choice.

I live in northern VA, and I found out the lovely green grass all over my five acres is japanese stiltgrass, an invasive weed with no nutritional value. So when I started out by filling the few bare spots with red clover, it was an invitation to a lovely doe, her three babies, and the three bucks that sniff after her. I haven't even planted my veggies yet, and these deer love me! At least the owls and fox keep the squirrels properly timid. But still, a veggie garden is going to have to manage hungry deer, rabbit, voles, raccoons, squirrels, birds, etc. So don't compare the greenhouse to a lack of infrastructure, but rather to a minimum to produce some veggies. We get maybe three cold spells a year, so I might heat a greenhouse fifteen nights on an average year. So that part is not hard once the set-up is done. We might need supplemental light, but that remains to be seen. And I hope to use the space for drying in the summer. Once I see what it does. Maybe I can get it to protect my corn in the summer.

I say veggies, but I don't eat a lot of nightshades like peppers and tomatoes. I would be holding some root crops in the darkest parts, and growing greens in the brighter parts. But why not trees in a greenhouse? Where did the food forest idea go? I would really like avocado.

In the house, I need to keep down the humidity. Plant selection can help - I'm thinking that purslane, pineapple, and cinnamon trees would be lovely and not transpire too much. How's that for an indoor guild?

Back to the greenhouse, humidity would be quite the problem here. There might be a geothermal solution, but I am a babe in the woods there. At least I know I have to solve the garage mold first, and maybe learn some dewpoint tricks along the way. At least a rain barrel.

So I think that the guilds and food forests of permaculture are a ways from hothouse tomatoes, but there has to be middle ground. What permie ideas work well in a greenhouse?
 
Robert Ray
gardener
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Location: Cascades of Oregon
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With the use of my greenhouse I am accelerating my perminess. I'll plant several varieties of a plant outside, of the blueberries I've determined which variety does better in my area and this year I have several flats of cuttings from that variety. The same with raspberries and honey berries. I'm growing them on site in a controlled environment. I'm elimating any footprint associated with ordering them from elsewhere, granted a small footprint but it is occuring within my bubble. It is a financial factor as far as buying from others. I'm giving my hazel nuts a season in a bigger pot to get a bit stronger before I move them to their permanent location. I do get food from my greenhouse but far more from outside. I can't afford to buy 50 blueberries, 50 raspberries and 50 honeyberries at once. However I have determined and can promote the varieties that have proven to be a producer for my area and can share what I have from my local cuttings and use of my greenhouse. My bioshelter my greenhouse is a permie accelerator. Look at me grow.
 
author
gardener
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Location: 6200' westen slope of colorado, zone 6
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Lyvia Dequincey wrote:But why not trees in a greenhouse? Where did the food forest idea go?
So I think that the guilds and food forests of permaculture are a ways from hothouse tomatoes, but there has to be middle ground. What permie ideas work well in a greenhouse?



I have been evolving my greenhouse, 24x38 footprint, into a permacultural food forest over the past five years. The greenhouse started out as a fairly typical bio-intensive lettuce and tomato seasonal rotation. It is now filled with vinifera table grapes hanging from the ceiling, hachiya and fuyu persimmons, brown turkey fig, arbequina olive, several pluots, and many diverse annuals tucked into raised beds beneath the trees. It does not suck.

The grapes and trees have reduced my maximum summertime temps by probably fifteen degrees on sunny days. The greenhouse is non-electric and unheated. I live in a zone 6 climate, with significant winter snows. This greenhouse, sheathed with standard polycarbonate triple wall greenhouse glazing, affords about 20 degrees of warmth on our coldest winter nights. So the greenhouse ends up being a zone 8 paradise. Our frost free season is roughly mid-march to mid-november, which is about 5 weeks longer on each end of the outdoor growing season. Vents are opened from June-August, which keep the max summer temperatures at about 100 degrees, much cooler at ground level.

There is a serious wow factor for visitors to the farm. The greenhouse is moist and lush, filled with fruits and aromatic herbs. I am by no means at the pinnacle of where I would like to be with this greenhouse, but I wanted to share some pics to give folks an idea of what is possible in a permacultural greenhouse. Enjoy!
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greenhouse jungle
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grapes hanging from celing trusses
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okra and basil under oriental persimmon tree
 
Lyvia Dequincey
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Wow. Gorgeous. I am stunned.
My mind is frantically calculating how to get there from where I am...
 
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I believe that ANYTHING you do, even if folks call it 'wrong', is better than doing nothing at all. The 'right way vs. wrong way' factors of building a greenhouse are fairly straight forward and uncomplicated. However, you still must know what those factors are and understand how they effect your final build if you don't want to rely on blind luck helping you create a functioning green house for your situation and location and needs. I have 3 or 4 books that explain these factors that date from the 1970's. I haven't looked at any reference books more current than that, but I presume outside of new building materials, the basic concepts are the same. I would hope that anyone who builds a greenhouse puts in at least some time researching the particulars. Outside of what I have read in greenhouse building books, my personal experience with my home built greenhouse has taught me a few things.

First, if you can dig a foundation for your greenhouse down to the frost line for your area, then by all means do it! If you insulate the outside of a cinder block foundation down to below the frost line, you are essentially getting free heat from the ground. This reduces how much heat you have to provide. Also, if your greenhouse is not getting enough light, either in terms of candles per square foot or length of day, then you are better off operating at a cooler temperature. Warm plants in low light conditions get leggy. You are better off slowing their growth with cooler temps. Do NOT make your greenhouse so freaking tall (like I did) that you can't employ night time insulation! Covering your glass at night will save a LOT of heat loss. I cannot do this because my greenhouse has three angles for the glazing (to catch both direct and sky dome) and it extends 20 feet into the air. I tried making a hinged insulating cover but it turned into a big sail in the wind. You could probably get away with clear plastic or similar over glass IF you are able to cover it with night-time insulation. And finally, STORE THAT HEAT! My greenhouse let in about half a million BTUs of energy on a clear sunny day in the middle of winter. But it would get so hot that I had to vent. My solution was to install water tanks, a fan and a heat exchanger (truck radiator) to store all that heat. While this violates the 'passive' test, I feel it is 100% worth it. You are not supplying heat to keep the greenhouse warm. You are using a minimal amount of electric to run the blower fan and the pump to store the free heat provided by the sun. It's either store it or waste it.

If we learn by trial and error, we make errors but at least we learn.
 
Posts: 17
Location: Western Washington Zone 8a
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I especially like the idea of the attached sunroom/greenhouse/greywater treatment. I'm in the process of designing a system for our future land (possibly very soon!).

I have a 6x6x6 vinyl pop-up tent style greenhouse which is pretty handy since I'm renting. It was great for tomatoes, peppers and basil when it had plenty of light at our old place. All were larger and more productive than their outdoor counterparts (same yard, a few feet away). At our current place everything got moldy because the backyard, while south facing is up against a narrow greenbelt of mixed deciduous and conifer and a nearby fence blocks crossbreeze. The tomato plant surprisingly supported a hefty crop of cherry tomatoes(tastier than storebought) despite the moldy stems, until late September. The air vents (velcro flaps) are at ground level, thus letting in tons of slugs and other little buggies. This was manageable in the open space yard of the old home, but was terrible next to the forest (duh).

It is definitely not worth it outdoors here, so we've moved it into the garage and invested a little more into replacing the functions of the environment. If I had been living here when I bought it, it would have been a terrible investment. Knowing that I won't live here forever, I'm hanging on to it and looking forward to being able to provide protection from browser's (bunnies, deer, etc) that is sturdy and portable. Maybe I'll eventually get around to designing a gutter with a small tank and drip irrigation tubing routed inside. I hated having to water in there while it was raining outside!





 
Posts: 92
Location: Madison, WI
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Nice thread!

I raise aquaponically year-round in my greenhouse in Wisconsin and I spend 2 minutes a day feeding fish and one hour every 2 months transplanting plants. Also I harvest.

That's about it. Haven't had any bug problems yet, though I know where I can get lady bugs and such if I do.

Hope I'm in the 18%

Jer...
 
gardener
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Location: Cache Valley, zone 4b, Irrigated, 9" rain in badlands.
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I sure see a lot of misplaced greenhouses. And mis-built dwellings as well. Someone planted an apple tree right in front of the solar collectors of a family members house. Every year I cut the tree back so that it doesn't shade the panels. One of these years I might just have to chop it off all together, and say "Oops. It was sick...". But it is a Jonathan, and that's one of my favorite varieties of apples.

As far as I can tell, greenhouses are not separate from mother nature... They have their own populations of weeds, insects, fungi, mammals, and bacteria, etc... They have pests and predators which live in some semblance of balance with each other just like any ecosystem. The best greenhouse ecosystems that I have observed set aside about 15% of the greenhouse to insect habitat, tailored if possible to the needs of predatory wasps. What a joy in January to go into a greenhouse and see bees working the flowers, and to watch parasitic wasps laying eggs on the aphids.

The biggest problem I have with my greenhouse is being able to afford to keep it functioning... Heat does not come cheaply. Therefore, most of the winter, I treat it as a walk in cold-frame. During a sunny day it gets about 15 to 20 degrees F hotter than outside. At night or during cloudy days it is about the same temperature as outside. As a walk in cold-frame it gets me larger plants for transplanting into the garden in the spring, and gives me 2-4 weeks earlier harvests on some crops.

But then when it's time to start the crops that cannot tolerate even a little frost, I have to heat the greenhouse at night to keep it above freezing. Ouch! Ouch! Ouch! It's still lots cheaper to grow my own tomato plants than to buy transplants, but the cost comes at the time of year when I can least afford out of pocket expenses.

In my very arid climate, the high humidity inside a greenhouse is a big bonus. I suppose that in wetter climates it can be a difficult to deal with.

When I plant things in the field, I might never even look at the plants again until harvest time... Things in the greenhouse require more attention, especially when planted into pots. I can take a day off, or a week off from tending the fields. The greenhouse requires daily attention when used as a hot-house. I gardened for 50 years without a greenhouse. I got along fine, but I'd sure be loathe to be without one if I had to move.

Then there are the malfunctions... Sure can be a pain if the door blows off at just the wrong time.



But what a joy when everything works together!

 
Posts: 76
Location: St. Ignatius, Montana, zone 5b
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Her in Montana, I think a greenhouse can be a good thing if it is in the sun at least 5 hours a day. Though I have 4 large hugel-raised beds 4'x20' each, and they have pvc tube supports for poly, I am drawing up plans for a passive solar sunspace on the south side of our future house. It gets sun almost all day and will actually bake in the summer if we don't have a plan for that as well. One plan is a heat sink system like they have at the community gardens in BC. Let the earth bank the heat until the ambient temperature draws it up. Heating your greenhouse A very important principle in Permaculture is multi-use and also problem solving. Making a problem a soluton. If the house sits baking in the sun on the south side, then a sunspace can help absorb that heat, store it underground and release it when needed all while providing a growing space for coffee and mangos - er, or other things. It can also be a pretty sweet spot to sit in the very early days of spring and late days of fall. It can of course help you jump-start and prolong your growing season and is a nice place to dry clothes if you want. We built a solar heater this fall, and have yet to install it, and man, I wish we would have. The sunspace becomes one big solar heater in the winter, but can become a solar cooker in the summer if not designed right.

There are some things we always have to ask ourselves as we make decisions about the buildings and structues we think about building... (1) what problem does it solve (2) is the cost less than the cost of the problem (3) can I use it for more than one thing, and more than 1/2 of the year, and of course, the biggy (4) why do I really want it, and will I really use it. #4 is where #3 comes in. If we have multiple uses for a structure, chances are it will get used for at least one of those uses. The more functional the structure, the more it will be used, which brings #2 into line since it's cost is now divided amongst many uses and helps insure that (#1 and #3) it is used for at least 1/2 of the year.

So I continue to draw different designs for my sunspace on the south side of the future house, and wonder if I can house chickens in it during the winter as well. Will I use an RMH or simple wood stove? Will I even need additonal heat? Planning is fun, but soon it will be 'go' time.
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raised hugel-beds with poly tunnel frames
 
Posts: 27
Location: Southern Colorado 6200 ft elevation, 20" annual precip, zone 6a/5b
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I have a 10x12 greenhouse that I knowingly built in a location where it would be frozen up in winter.

Our building inspector told me that I couldn't build a retaining wall more than 4' high without a permit. Then he told me that I could build any structure 10x12 or less without a permit. I needed a wall about 30 feet north of our two story house. So I dug it out and built a greenhouse with insulated concrete block walls, a second-hand cedar frame and single layer polycarb cover.

Today we brought in two large boxes of lettuce since it is forecast to be 14* here tonight and I know the greenhouse will freeze. It has only been a few weeks since it got much direct midday sun, but it still grows lettuce if it is planted at the right time in late summer.

I usually grow a small crop of lettuce planted inside in Feb and moved into the greenhouse after two or three weeks. We harvest it in May (in any stage of growth) and transplant in tomato plants that have been started indoors. In August I start lettuce indoors and plant it as soon as the determinate variety of tomato has produced. From about June until September I cover it with a 30% shade cloth.

It cost me about $2k to build this thing about five years ago. Other than the lettuce-tomato-lettuce cycle I've described I also have room for a variety of other spring/fall starts and pots of basil, early spring cukes, etc. For our situation it has been wonderfully worthwhile.

Tomorrow we will host a post-Thanksgiving dinner for an extended family group and we'll be feeding them a huge home grown salad along with soup containing lots of home grown stuff!

It's all good!
 
Posts: 26
Location: SW Alabama zone 8a & 8b
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I would like input for a scenario in which I think a greenhouse would not suck.  Suppose one has a lil' acre in between 2 cotton fields...not organic.  The lil' acre is subject to drift from degussa and glyphosate in the spring and summer.  In the fall it is subjected to one of the myriad of toxic defoliants.  The occupants of said lil' acre have no where else to go atm, and really need to be able to grow some yummy organic foods and start an aquaponics system featuring koi, yabbies, minnows, and perch or tilapia (diversification).  The occupants have secured an order for 10K baby koi for next breeding season (spring).  They also have several restaurants interested in their produce and edibles.  The minnows are sought after by local bait shops.  Is there a better way to protect the occupants of the greenhouse sheltered aquaponics system?  A poly-tunnel will not work due to animals and possible tears at a time when spraying is happening.   There is no possibility at this time for the occupants to move to a less hostile piece of land/area.  I know this thread is old so I hope I get some responses.
 
Posts: 180
Location: Boise, Idaho (a balmy 7a)
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chicken goat solar trees urban wofati
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I have been amazed at the performance of real polycarbonate cellular sheet and two piece aluminum clamp system with a LVL wood structure.  The orientation issue is tantamount to success and in your area, likely a mechanical ventilation system or a better understanding of what Mike Ohler suggested with mass and strategic openings.  A regular greenhouse without massive ventilation and shading is an oven in your area.

I would suggest Sskylights and a metal building would be more than adequate for fish farming in Alabama, you might even  find a metal building to salvage and re-use...now that's permie.
 
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while it might not be worth the invested time/resources, if you make it yourself on the cheep, have limited space and seasons are short, a greenhouse in a bad location is better then no greenhouse at all.
 
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Gwen Lynn wrote:If I lived up north (been there, done that), I don't think an ordinary greenhouse would be enough for me. I would NEED my own, personal, human sized terrarium! Complete with skylights, a waterfall, indoor pool and greenhouse area for overwintering tropical plants, starting seeds, etc.
...



You mean like this?

 
The only cure for that is hours of television radiation. And this tiny ad:
Solar ovens, haybox cooker - What would you build to go with a rocket oven?
https://permies.com/t/89917/Solar-ovens-haybox-cooker-build
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