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Greenhouse and heater question.

#1cheesebuds

Well-known member
Veteran
If I bought a greenhouse to put in my backyard to keep my outdoor plants in the greenhouse this winter does it need a heater? I live in Texas so it doesn't freeze here as bad as every were else and we don't get snow that much either.

recommendations on what to get would be great.
 

CrushnYuba

Well-known member
It all depends what your goals are and where on Texas. Are you trying to grow ALL the way through winter? Are you trying to flower all the way through? Is this for light depp or is this just to keep your outdoor starts and genetics alive and thriving through winter. You may not really need heat. You could probably get away with a little space heater for the 2 days a year frost is predicted just to keep them from freezing. If you describe your goals and climate better, i can make a recommendation. I keep my greenhouse going all winter.
 

farmerlion

Microbial Repositories
Mentor
Veteran
#1Cheesebuds, dairy room heaters are small and very efficient. One or two should serve you well. I switched to them instead of propane. Only $20 per heater.
Peace. MedDakotabis
 

#1cheesebuds

Well-known member
Veteran
My goals are to keep my outdoor plants alive the winner in a greenhouse.mostly just regular flowers and vegetable plants. but it would be nice to grow some cannabis cuttings out there in the mix get them to grow through the winter. Talking mother plants and clones along with vegetable plants.

So the person I'm living with and I both agree that it we don't want it to be ghetto looking but we also don't want to spend a fortune on something overly fancy. if I was rich that be another story.

PS: thanks for the info.
 

CrushnYuba

Well-known member
So i got a thread called "diy steel frame greenhouse". Most of the pictures are gone i think but the info is great and I'll try to find some pics or take new ones. You can bend tube steel yourself super easy and dirt cheap. Indistinguishable from an expensive greenhouse kit and Will last FOREVER. I use pellet stoves in mine but mine are pretty big and it snows here. I bet you can get away with a space heater or 2 for your needs

How big of a greenhouse do you want? Keep in mind, if you want to grow during the winter you will need a couple regular light bulbs to extend days. If you are in a suburban place it will draw attention. During the summer, you will need to black it out for light depp or the plants will outgrow the greenhouse. You can do a cheap automated light depp that will solve both those issues.
 

MJPassion

Observer
ICMag Donor
Veteran
If you want to keep veges like tomatoes in the GH you'll need to keep temps no lower than 50F.


Otherwise cannabis can handle overnight temps below freezing for a couple hours at a time. I wouldn't let the GH get below freezing if it were me though.
 

Lester Beans

Frequent Flyer
Veteran
Rocket mass heater. Simple to build and efficient to run. Being in a decent climate it would be perfect for you needs.
 

highsteppa

Active member
Veteran
I’d just get a forced hot air propane heater...IMO the heat is needed to mediate high night time humidity, esp late in flower.
 

CrushnYuba

Well-known member
For a cute little hobby greenhouse, you can use a propane rv furnace. They are cheap tiny little VENTED propane furnaces.
 

LostTribe

Well-known member
Premium user
#1Cheesebuds, dairy room heaters are small and very efficient. One or two should serve you well. I switched to them instead of propane. Only $20 per heater.
Peace. MedDakotabis

If you are using propane burners and you seal up the green house you would have the advantage of supplemental CO2 though?
 

CrushnYuba

Well-known member
Unvented sucks. You have to keep in mind greenhouses aren't insulated well so they have to run allot more then if it was in a building.

Burning propane puts out allot of unwanted moisture. And unwanted gasses. I have seen plants get sick in greenhouses with unvented heaters. I have seen it happen a few times. Also u mostly have to heat at night and you don't need extra c02 at night.
I would rather pay more for electric. I use pellet heat in my greenhouse and it kicks ass and is dirt cheap. Pellet stoves and furnaces are not cheap but they are cheap to run.


Vented furnaces only for me
 
X

xavier7995

I am real excited to see how my little greenhouse does this winter, came with the house. It is only 4 or 5 x 8 or so. The thing is really well constructed and has misters and a swamp cooler for the summer with a thermostat, there is a plug for heat...but so far havent put anything in there and stuff hasnt died. Hopefully i can keep the weed going through December, i think trying to extend into January and February without supplementing heat would be a mistake.

The recommendations for some of the smaller heaters are really helpful, keep em coming.
 

CrushnYuba

Well-known member
Wow. That's a really intense 4x5x8 greenhouse. Don't think i have ever seen something so small so tricked out.

For small heaters. To heat a little hobby g house. I think there are really only 2 options. A little electric space heater like farmer lion suggested. Or an RV propane furnace.
A 1500w space heater produces about 5k btu. Most Little 12v Propane rv furnaces put out about 16k or so after accounting for efficiency loss. They are the smallest VENTED furnaces you can get. You get a Little thermostat for them and they turn on and off when needed.
The only little hobby greenhouse i have is for keeping moms alive in the dead of winter. I use a propane rv furnace i picked up off eBay used for 200$. You can find em used everywhere.
 

Steven/nevetS

New member
What about placing oil drums filled with water / or conductive non flamamabe / ignition free fluid to collect the daytime temps when the sides are up, closing at night?
May not hold the temps all night through but could even go a step further running a hot pipe & cold pipe; hot pipe running along side or through with the cold pipe also having the abbility to dump hot and cold into enclosed and qealed barrells with an overflow?
Or even just recirculate, feed aquaponics.
Possibilites could keep going.
But ambient heat from day to day & fans kept just bellow their min optimal speed?
For starters to see how it goes?
 
Being in Texas, I’d definitely put as many black water containers on the south side as possible. An electric space heater and water in black or dark color containers would be your best bet.
 

CrushnYuba

Well-known member
Drums don't do much. We have tried all sorts off shit. They take up allot allot of space. U need do many too even make the smallest difference. We tried burying them halfway with a tractor and growing on top of them. They just don't do enough really..
I have been using these small vented diesel furnaces that are super cheap and way convenient. They work great for smaller houses. They won't do my big houses though. They are about 200$ and they put out the hear equivalent of 4-5 space heaters. U can use kerosene or heating oil in them. I use off road died red tractor diesel.
 

romanoweed

Well-known member
I can imagine in Texas you have often no clouds even in winter. I heard you can put just Rocks into the Grenhouse, where The Sun shines on, and they will store some sungenereated heat, wich they will give away at start of night. Easy trick, just place them in. Also the greenhouse-heatup does only happen IF sun shines, and again you in Texas do Profite more than in a more clowdy place. Third Thing is you can Build a wall at the northern Side of the greenhouse, and partly a the Roof, where no sunshine Comes from to SUBSTENTIALLY Isolate the greenhouse. I also agree, that some cannabisstrains can survive minustemperatures quiet well. They might stagnate Abit, but they dont die. Some Thais, or Nepal Strains can handle that quiet good. So i see not that big of Problem growing even equatorial thaistrains. If it gets 100 Percent topquality is questionable, but 80 percent Quality is enough , no? What you envision?


Oh and shure double glass would hold more warmth in, as plastic, but they filter uv wich is debatted to be important for resinproduction.. So, i would still take plastic, and it holds in Abit of heat (5 degrees celcius) . To my understanding intense sun could be same important if you want to have 100 percent Quality bud..


For that i have a possible solution on this exact page, preflowering the plants indoor (this is for 18 weeker Sativas rahter) : https://www.icmag.com/ic/showthread.php?t=360394&page=15
 
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romanoweed

Well-known member
Another Thing is: if you use one layer of Plastic you Isolate a bit the heat.. if you just place a secound Layer of lastic a couple Centimeters apart you Isolate even more. Cause Air itselve doese Isolate heat, and trough Holding her at Place (therevore not mixing up) you gain more Isolation. So double layering is good for more isolation
 

Rico Swazi

Active member
I have friends north of San Antonio that use soil heating cables in a large bed in the greenhouse.
They harvest from their garden year round including cannabis.


I have two plants growing now in an indoor outdoor scenario that I have done before using seedling propagation mats for bottom heat.

I have found as long as the roots are relatively warm, the plants will grow despite cooler ambient temps.





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Looking to chop in two weeks then reveg for a spring crop
 
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