# Anyone Growing in a Greenhouse?



## The Hemp Goddess (Jul 8, 2019)

It has become obvious to me that I'm going to have to build a proper greenhouse if I want to grow where I am living.  Although I only moved about 75 miles from where I was, the temps are quite different as I am further north and higher.  On the plus side, I am not going to have to try and deal with weeks of 100+ temps.  However, the cold is a problem.  Even now temps at night are in the 40s and 50s and I am not sure that they are going to get much warmer (although I have been told this is a cold year).  Thee was a frost the middle of June and I anticipate that it will frost early in Sept.  My 7 week old plants look more like 3-4 week plants and I believe it is the cold and wind.

While I will not be able to construct something this year, I am hoping to get something erected early spring next year and am looking for ideas and input.  I am thinking something in the 10 x 12-16' range.  As I am renting, I would like to try and make it so that it could be removed and relocated if needed, but this is not essential.  I am hoping to keep material costs under $2500.  I have someone adept at construction who will do the framing up for me for free and I am pretty handy myself, so costs will be limited to materials.  Looking for suggestions and ideas from anyone who grows or has grown in a greenhouse or anyone with greenhouse knowledge.


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## Rosebud (Jul 8, 2019)

I don't have any of that knowledge but i just wanted to tell you that I know you and you will make a rocking greenhouse and will be growing all your own food someday. Green mojo for the project!


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## thegloman (Jul 8, 2019)

HG
I built my greenhouse out of 2" PVC conduit as it has UV protection in it.  
I made a hoop house that was nice untill this winter when the heavy ice snapped all the PVC and in collapsed in on itself.
Had 1 solid sheet of 6mil. plastic as the cover.
Very easy build.


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## The Hemp Goddess (Jul 9, 2019)

I have ordered a 10 x 10 portable greenhouse to get me through this season.  The framing is 1-3/8 powder coated steel and the plastic is reinforced probably 6 mil or better, so hoping it will stand up to the winds, also going to batten it down.  I am going to put down 4 x 4s for a foundation.  I want to to get it put up in the next few days.  How large was yours?  Can you tell me about your climate and how you ventilated it?   I am concerned about the heat on the days it gets to 90 or so.  There is a door on one end, a large ventilation window opposite the door and the bottom of the plastic will lift up for added ventilation.  I have 2 6" Vortex fans, figured I could utilize one of them and numerous oscillating and box fans.  Any advise on managing a grow in a portable greenhouse would be appreciated.    

Ultimately though, I am thinking that I am going to really need a semi-permanent structure, framed up with lumber and using double-walled polycarbonate panels to do what I need it to do.  We will get snow here and the wind can really blow sometimes.  LOL--knew when I rented the place that if I can see wind generators on the mountains out my back door that I should expect wind.


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## orangesunshine (Jul 9, 2019)

sounds like good fun thg---consider screening all areas that may be open at any given time---good to keep bad bugs out and beneficials contained---gravel floor is nice---run enough electric to handle the load for anything you may want to add in the future like a space heater, supplemental lighting, pump, etc---am confident you have great vision for your plumbing in hydro or soil---surely you will be facing south---hope to see your progress---diy is the best and no doubt you will knock it out of the park


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## The Hemp Goddess (Jul 11, 2019)

Thanks orange!  I m writing all this down--have a notebook for greenhouse planning.


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## zem (Jul 11, 2019)

Hi THG! I have built a greenhouse 7 years ago and is still standing like new. I made it from galvanized pipes and since you are a plumber you know a bit about them I guess. I have found companies that specialize in making the structure at custom sizes and it was cheaper than I expected. It can be dismembered and moved. If you know of a region that is reltively close to you and has a high concentration of greenhouses, then there is a high chance that there are such commpanies there that do this over there. It is quite primitive the factory, just bending cutting compressing with louver, mostly mechanical machines and welding is done with propane. After my experience with them and their durability/price vs other matrials, it was clear why it is the material of choice for most greenhouses. a skilled worker could even figure a way to do all that from straight pipes. 

For easier warming, the greenhouse should have a low ceiling. It does sound like a cold area to frost at those times of the year. Look into polycarbonate cover for the greenhouse, it is better at insulating the heat. It could be difficult to warm up a bigger area so you might want to consider that when choosing the size, maybe try smaller better insulated at first. The biggest obstacle is climate control, you will probably need to be able to easily provide shading, and open and close the sides as much as possible while keeping the pests out as much as possible. I use a net for that.  I think that you will like the results and never ever look back  good luck


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## Fat cat (Jul 11, 2019)

Fat cat here I went on the cheap .I bought  a old milk truck just the back (box)  for $75 scarp price .plate windows from scrap pile 40 bucks for 4 set box in yard right up traced out window size on roof cut out in stalled .has openings at both ends great air flow.works even better in winter .4 ft deep out side .it is instlated beyond belief kinda cool in the middle of winter just have to clear snow from windows.some days can't win but sun is strong when out.think of things to recycle for other uses .it's 10by7 inside.goog luck


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## The Hemp Goddess (Jul 13, 2019)

Zem, thanks--this is the kind of info I need.  I am pretty sure that I will be doing a lumber frame up--wood is fairly cheap here, I know of no close greenhouse manufacturers (I am in the middle of nowhere), I have a retired general contractor to help for free, and I only need it to last as long as I do.  However, I am planning on double walled polycarbonate.  The north wall will be solid and well insulated, maybe something like T1-11.  Working on climate control now with my little portable greenhouse.  What temps should I aim for?  Right now (4 in the afternoon), with a little breeze, no fan, and outside temp of 84, the greenhouse is 97 degrees with 13% humidity (LOL--need to deal with that, too).  I think I can pull some cool air from under the house and get it down 5-10 degrees.

Fat cat, what an inventive idea.  While I am looking for something larger and more permanent, this is an idea that may appeal to those looking for something smaller and less expensive.  Thanks for chipping in.


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## 2RedEyes (Jul 13, 2019)

Here were I live there is a kind of swap meet flea market thing...there is a guy there that makes fitting for joining various tubes... I guess that certain sizes of electrical conduit fit perfectly inside certain sizes of chain link posts...not sure which fit in which but they work...he makes parts for joining these together at the roof peaks and also at the side where they meet the roof...you put them together and lock with self tapping screws...make a sturdy structure that you can disassemble should you want to move it...I had one long ago that I parked my motor home under...you can cover with whatever suits...just another idea...


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## zem (Jul 16, 2019)

THG you are the most welcome it makes me happy to be able to help you  You should aim at regular mj temps I don't like it to go to more than 87. If you can get a proper shading and can open the sides of the greenhouse, and add fans, you should be able to get temps slightly lower than the outside  without any further cooling. for that low a humidity which I never ever seen, I think a fan that gives mist or an active humidifier would be handy. I have concrete floor and rarely see lower than 40% so I just mist floors and walls to aid in cooling by evaporation. For a low ceiling greenhouse which you want, it is much more effective and easier to shade the greenhouse from the outside that is from over the poly ceiling. Fans to move the air around in a greenhouse is a complete must ime. It is not like the indoor where a small clipfan would suffice, for your plan maybe a couple of 10" oscillating fans would do. You could try find something basic without a base or speed control since you could simply hang it with a string.  There are specially made fans for greenhouses if you don't have old oscillating fans laying around. If these temps are the highest that it gets in your area, then your hassle will be heating. With very low temps, you might require heating to pull anything in those periods.


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## orangesunshine (Jul 16, 2019)

love to hear your are framing up your own space---i would be going with a sw facing long side rectangle shape, isle down the middle buckets 2 deep on each side---for a proper fit, $ wise, and no waste---i would also decide what size plastic fits your budget before you decide the size of the greenhouse---you will want to be replacing it annually---as zem points out the smaller the space the easier to heat but don't short change yourself with too low  a ceiling and keep in mind the possibility of supplemental lighting---i wouldn't go less than 8' height---shading is great if you are flowering in the summer  and not so important in the winter unless you need to black out nighttime lighting from neighbors


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## zem (Jul 17, 2019)

Hi OS  my frame in the middle of the ceiling curve is just 8.2ft at the top of the curve. I use 200micron polyethylene and it lasts 2 to 3 years. I guess that good polycarbonate boards should last a decade or so.


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## orangesunshine (Jul 17, 2019)

hello Zem---think goldilocks and the 3 bears---1 size never fits all applications---surely thg will research the sheit out of what will work best for her budget and environment---polycarbonate boards would certainly be the call  if she may have a heavy snow load and freezing temps---glass would be better if she has little snow and temps freeze occasionally---and plastic would be just right if temps don't dip below freezing---imo replacing plastic annually is for piece of mind and pretty consistent with changing out your grow lights for maximum efficiency---although the bulb will illuminate for years---it loses its efficiency over time---some people change out their bulbs more frequently than others--- plastic in my neck of the woods degenerates pretty quickly due to the intensity of the sun---changing annually is preventative maintenance---allows for flexibility of opening additional venting if need be---it's no fun replacing plastic if the greenhouse is full of flowering plants---i have no doubt---whatever product she chooses will be most appropriate for her environment


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## zem (Jul 17, 2019)

Oh yeah OS I can only imagine how much more the greenhouse would have to face in different conditions. I just recalled one time when I had to do an emergency plastic changing because of grail the size of golf balls that made the cover of the greenhouse look more like a net. That was not fun.


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## The Hemp Goddess (Jul 18, 2019)

Yes, I am in freezing temps--I'm at the 45th parallel and 3300' and it looks like the area gets a couple of feet of snow a year.  We may get a bit more as we are at the foot of some mountains.  I'm planning on double-walled polycarbonate.  I would rather have a smaller better built greenhouse than a larger one of lesser quality.  I will not grow year round--winters are simply too cold and at the 45th parallel, we don't get enough light in winter.  Thinking, however, of putting a small portable hot tub in there in winter....  

LOL--aren't those humidity number something?  I have lived virtually all my life in high desert and arid conditions.  The slightest bit of humidity renders me almost useless.  I don't know how those of you in humid climates do it--I am such a woose.  I ordered a mister for the portable greenhouse I have up.  Trying to figure out how to feed it.  Water in the hose is so hot initially.  Maybe a bucket with a water pump and a timer?  Or think I just got an idea how to run a hose bib to within about 5' of the greenhouse.  Having this portable unit up this year should help me figure out what I am going to need in a permanent structure.

All your suggestions are very helpful and greatly appreciated.  I am keeping a "Greenhouse Notebook" with ideas, pics, and links.


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## zem (Jul 18, 2019)

Water in the exposed hose is very hot indeed. I have control reservoirs that I feed from automatically . Consider the space that you have, maybe it makes sense to build it bigger and make one bigger grow in the warm season and just let it rest through the year? Warming up a greenhouse requires fuel or gas and equipment and nothing beats a naturally goo season. Another plus is that when you leave long intervals between grows, it is more difficult for pests to take hold and if you are using ground soil, it is easier to maintain the soil and amend it between grows.


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## cannabisismylife (Jul 19, 2019)

Rosebud said:


> I don't have any of that knowledge but i just wanted to tell you that I know you and you will make a rocking greenhouse and will be growing all your own food someday. Green mojo for the project!


Yea, keep it up. The final product will blow it up.


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## The Hemp Goddess (Jul 19, 2019)

Oh Zem, I am hoping to only have 1 grow a year, but as I got such a late start this year, I will probably have to have an indoor winter crop.  It really gets too cold here to grow outside year round.  The purpose of the greenhouse is simply so the plants can get a May start and finish in the fall.  We can expect a hard frost anytime before Memorial Day and anytime after Labor day....and sometimes even during the summer months.  I will need heat in the fall.  I'll probably go with a propane heater.


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## zem (Oct 2, 2019)

Hi THG! Did you get to complete the greenhouse for the fall? Any updates?


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## The Hemp Goddess (Oct 2, 2019)

Well, the "real" greenhouse is a project for the spring.  But, I did put up a smaller (10 x 10) portable greenhouse--you know--one of those cheaper things with the metal frame and plastic covering.  I made a foundation with 4 x 4s and staked them to the ground.  There is heavy duty landscape fabric on the ground.  The greenhouse had held up well through some big wind and rain storms.  Weird to have to go out and water plants when it is pouring rain.  Last week, I put a milk house heater in the greenhouse and set the Vortex fan up to recirculate the warm air.  We have had temps in the 20s the last 4 nights (25 last night).  The heater keeps things above freezing (barely) and warm enough during the day that they don't stop growing.  If it gets colder, I will need 2 heaters, at least right before dawn.  Now though, with the early morning sun shining on it, it is 56 inside with an outside temp of 27.  Quite a bit colder here than where I lived before--it has made growing outdoors a challenge.  I'll be better prepared next year.

I have been looking at some greenhouse kits that have decent reviews and are affordable in the $2500 to 3000 range.  A lot of these come 8' wide in a variety of lengths up to 20' or so.  Still kicking things around though.  If I could find 4 or 5 used glass sliding door sets, I might stick build something.  There is no reason at all to have the north wall anything but solid and insulated, so may end up building something.  LOL--I think I'm going to have a long winter to plan and decide.


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## zem (Oct 3, 2019)

This is great! I am wondering if you could excavate a few feet into the ground maybe this could help with the insulation? I am not sure just imagining how it is to grow plants in such a cold place. Also I wonder if one would dig a few feet and burry some ducting where cold air passes, if the air would warm up as it passes through? I recall seeing a video with someone burrying a lot of ducts in a greenhouse just cannot remember if he they were using forced heating or for just for passing air through. The method that I saw on hydroponic raised plant rows is just hot water pipes that go all the way around the rows where the root level is. Water is heated with propane and seldom the propane burning is used to gove extra CO2 as well. If you like to see some big grow ops and several of them are in greenhouses, check the growers' network channel https://www.youtube.com/channel/UCQJgC72WQy8KmNkWD8IzuUA  I like it because it is fun and I learn new ideas at the same time


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## The Hemp Goddess (Oct 3, 2019)

I have lived in cold climates my entire life.  I often wonder--as both a plumber and a gardener--how much easier both would be if I lived in a milder climate.  Just to give you an idea, water lines need to be buried 1 foot below the frost line.  Where I live, that is 4 feet.  This kind of rules out burying ducting deep enough to benefit from the heat the earth naturally puts out.  I do like the idea of a propane burner and will look into that with the "permanent" greenhouse.  The extra CO2 is like a bonus.  The place I lived in Idaho has a huge amount of geothermal activity in the area and I worked with a variety of hot water systems.  So, while I will not use the greenhouse year round, I will probably need to have plants in there until the end of Oct.  I figure that I will need auxiliary heat for about a month.

Thanks for all your help and suggestions.  I'll check out the link you sent.  I also like new ideas.


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## longtimegrower (Apr 1, 2020)

Sounds like you moved to flagstaff. Ive got afriend in arizona.  Just guessing.  75 miles doesnt matter that much here.


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## HerbWatcher (Apr 2, 2020)

I know there has not been much action on this post lately. But I thought I would jump in anyway. I'm just starting to build a 10x12 stick built green house. The foundation is simple, i just layed 3 2x4s flat the 10 foot direction. Drilled three holes in them then pounded three foot rebar through them into the ground to keep them stable. Next using 2x4s i built a 10x12 box that sits on top of the three 2 bys on the ground. I ran 6 joists in side the box 24 on center . Layed down half inch plywood on top of that for the floor. Next the walls will be 8 foot tall with two by studs 24 on center to match the floor. I'm going to grow 6 plants so I'm going to install six fans ( one for each plant) at the top of the eight foot walls. Now for the roof, i decided to go with a gambrel style roof. I want more height where the roof meets the wall. Reason being is that I'm going to be growing in 20 gal. trash cans, so they will be sitting up about 3 feet off the floor from the get go. Plus I like the look of the gambrel roof. This style roof looks like a barn. 
Like the HG i want to use 4x8 double wall polygarb for the skin. 
But this is where I am having some concerns. On the long ends of the sheets they are open. On the sides they are sealed.  The process the mfg states to install these panels is kinda lame and costly. Now I'm not sure how all this works, but the mfg states at the end of the sheets where it is open you are suppose to use this special tape. Actually 2 special tapes. They state that you install one tape on top of the sheet, which is a solid tape then you install the other tape on the bottom of the sheet, which has holes in it to stop moisture from building up between the double wall sheets. 
I don't get it how will this stop rain from getting in there then?  
Then for the sides where you attach them together the mfg sells these plastic H brackets that you slid the sheets into then you are suppose to screw in-between the two sheets into the plastic H brackets into the studs. 
Just an accident waiting to happen. 
Then on top of that these H brackets are black so I see these lasting a season, maybe. 
I'm afraid i might have security issues, because I don't live where i grow. That's the main reason I want to use the polygarb. This stuff is 25 percent stronger than glass and just about unbreakable .
So if anybody has experience installing this stuff maybe you can help me understand this process. 
It just doesn't seem to be very efficient to me. Seems like there will be alot of problems. Plus the cost for all these extra things to install these sheets kicks up the price like 30-40 bucks per sheet. And the sheets are $60 direct or $80 from home Depot. 
So just to skin this 10x12 green house will be over $1000. 
Thanks in advance. And I hope you all have HIGH day. 
Ps sorry this was so long.....


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## The Hemp Goddess (Apr 3, 2020)

Thanks for the input.  I am thinking of greenhouses again, but I have moved again, so it is a new ballgame.   We bought a place and moved from northern Oregon to southern Oregon.  I'm about 12 miles outside Klamath Falls (4100' elevation).  We have an acre and a great backyard that is open to a lot of possibilities, so have been looking at greenhouses seriously again.  At 4100' we are going to need it in the fall.

Even with a portable plastic greenhouse I wanted to have a good foundation (and not blow away), so I put down 4 x 4s that I staked to the ground with 2' ground stakes.  I didn't build a floor, but put down a heavy weight landscape cloth.   With a permanent structure, I will probably do the same or maybe put down a cinder block foundation.  I will still use the landscape fabric for the floor.

I have also noticed that the tapes and metal that they use on the polycarb sheets seems expensive and laborious and I am exploring other things.  Pinterest has plans for a couple of gambrel type greenhouses that use the corrugated polycarb that is cheaper.   But that too is still fairly expensive, is single wall, and has special things you need to buy.   My latest idea (which I am researching--not all my "ideas" are feasible) is to build a lean-to type structure off the back of the garage utilizing used sliding glass doors for the walls.  You can often pick up old sliding glass doors for $100 or so.  Most of them still have screens and they come in sizes from 5' to 8'.  Then the only part that would need the polycarb would be the roof.  Also a money saver as I would only need 3 walls and I could pull electrical from the garage.  

I can't imagine having a greenhouse that is remote from where you live, security issues have to be a nightmare.   It is not like the double wall polycarb is going to be strong enough to prevent breakage if a person wants to gain entry, though.  I think it is more like it won't break during a bad hail storm or with high wind.  There is little that can actually deter a determined thief.


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