Does anybody keep a Greenhouse Heated all winter?

In Zone 5 or lower? I have to write up a business plan and need some info. Thanks in advance!

I live in zone 4, and you can't grown year round without a heat source...
I will be setting up a temporary greenhouse 6x10(plastic) 20lb propane heater(with an exhaust nearby.

That's what I need. I need some costs for heating. Which is more cost effective, propane, wood chips, oil, etc.

a gas heater will give off ethylene gas which may distort your plants but with proper ventilation it can work.....propane is really expensive but where I live it is my only choice.. wood chips if you want to spend your time feeding the fire..... a boiler is the best choice I think, or an RV furnace....depends on your cash flow.

How big of a greenhouse do you want and what do you plan to grow? Wanda

Tropicals. I can't decide though if it would be cost effective. The idea of a green house is appealing yet I think I could produce the same results with 5 or 6 grow light stands placed in a spare bedroom, without extra heat costs involved since I already heat the bedroom. Funny how the mind flows..I've just pretty much talked myself out of a greenhouse!!

check out ebay for a greenhouse! got a 6x10 for sixty dollars, heater was 12.00!!

I think in your zone to grow tropicals you're going to spend a good chunk of money on heating no matter what method you use--it's not just a matter of keeping things above freezing, if you want them to be happy and healthy and ready to sell you're going to need to keep them probably at least at 50-55F and I'm not convinced you'll make enough money off the plants to cover those heating costs (at least until your business is well established). If you've got a spare bedroom you can use I'd definitely recommend doing that for starters until you get your business up and running, then if you're having a lot of success and need to expand you'll have a much better idea whether you'd make enough extra money with the extra space of the greenhouse to justify the cost of the heat.

That's what I'm thinking now too. Funny how sometimes just writing something down gives a whole new perspective isn't it? It's like the typing leads our mind...much more than just thinking silently to oneself.

Grow lights are definitely cheaper, if you have a good place for them. I heat my 20X20 greenhouse all winter and so far since fall its been around $800, but I'm about due for a fill up on propane (another $800)and it will take one more tank at least before spring is here enough to quit heating. I heat it to 50 degrees minimum. The greenhouse has a triple layer plastic inflated on it.
On the other hand, my grow light in the basement with a light mover cost about $600 for the setup. It runs a 30X10 area pretty well for $30 a month on the light bill. So if you don't need much space, it would work for you.

Thank you. Problem solved...can you post a pic of your set up?

Hey Folks, check out the link to figure out how much heat you will need for the coldest nights. They list some nice options for heat source. I don't start up the greenhouse until March 1. There's only 8-3/4 hours of daylight right now.

The Little Buddy heater that I have is propane and 2 settings 4000BTU or 8000BTU. for a 12'X8' gh. This heater was $80. It has a pilot light, but no thermostatic control only the two BTU output settings.

http://www.littlegreenhouse.com/heat-calc.shtml

I have the same set up as Joanna only my GH is 6x8. I lined it with bubble wrap this past weekend and it added 10° of warmth. Before, if it was 32° outside, the heater made it 42°. Now, with the bubble wrap , it was 27° this am and the GH was 46°. So the bubble wrap was worth the work of installing in a full GH. ^_^. My flowers are all blooming. The columbine is especially active.

I only heat when the temp is going to drop below 35°. I have found that my plants are hardier than first thought. They have done fine with the occassional dip to 28° in the GH because the weathermen were way off on their forecast. Like last night. The low was supposed to be 32°. It got down to 27°. I'm glad I had the heater on.
My GH runs about 4° cooler than the temp here at the house. The GH is out in the open about 100 yds from the house on the southside.

No kidding - did you buy special bubble wrap or was this the standard packing stuff? I was told that it wasn't worthwhile - but of course, I was told that by someone selling me something different, grr... I ended up with the double layer of inflated poly, and I am not certain that it makes a huge amount of difference.

The double layer of inflated poly is going to work better than bubble wrap plus a single layer, but they both work on the same principle that if you can trap air between layers of plastic it helps to provide insulation. I use bubble wrap on my GH too--I bought stuff from Charley's Greenhouse which I think was UV treated or something to make it hold up longer in greenhouses. I'm not sure if it's made a difference or not though, my GH is raised up on a deck and there's no bubble wrap on the floor to prevent cold air from sneaking in that way.

I bought my bubble wrap at Wally World. The big box. I know there are other places to buy it in bulk on line. I notice only one difference with it. It allows the GH to heat up 10 more degrees when the gas heater is on. So my GH will be 20° warmer than the outside temp instead of 10°. I haven't noticed any difference in solar heat retention. I do have thin gaps between the aluminum frame and the wood base the house is attached too. I know cold air comes in there because I feel it. But since I use propane heat I need some oxygen coming in or the unit will shut off. It's not alot of cold air but enough.

Hi,

I have a 20x50 foot greenhouse that I grow in all winter. I'll tell you right off the bat that it was not cheap to build. I figured if we were going to do this right, we couldn't skimp on supplies. We dug a foundation down to the freeze line and insulated that, used 16mm poly, lined filled drums along the north wall and we also poured a concrete slab running the length of the GH that has radiant floor heating in it. We also have the radiant tubes placed at the bottom of our beds. Our house was totally off the grid so we already had a wood burning boiler for our heat source and tied that into the radiant heating in the GH. This is a very brief synapsis, but gives you some idea of the lengths we went through to have it year round. If you are looking at building a smaller greenhouse, I would HIGHLY recommend "The Greenhouse Gardener's Companion" by Shane Smith. He goes into good detail about components needed to make a "solar" greenhouse with no additional heat required. It is very straight forward and helpful. He lives in Wyoming and grew at around 8500 feet (I think) with no heat source other than the sun. Also, check out this site.

http://www.geodesic-greenhouse-kits.com/

I've looked at a couple of these in our area and they are working out great.

hi upforthechallenge! Greetings from Stevensville(south of Missoula)

I will check out your links. My husband wants to put radiant floor heat in our greenhouse plans, that would run off a boiler in the barn. Do you heat year round? Do you need other heat sources?
could you please d-mail me?thanx

thanks too Joanna and texasgrower for the bubble wrap idea! will use the wrap on our 6x10 GH

I agree with the rave review of The Greenhouse Gardener's Companion -- super book! Got one for a Christmas present, while still building my little 6x8 greenhouse. I'm in Zone 6 and temps get down to 5 or 0 sometimes -- typically between 10 and 22. One hint I got from the book is to keep water bottles inside -- I don't have any big containers but had started saving empty gallon milkbottles a long time ago, for a different project, but filled them up and put them inside the gh. They work great even though I only have about half the water (about 60 gallons) I should have (need about 200, per the book). They really do soak up the heat in the daytime and release it at night. My greenhouse is made from an old steel frame my son's neighbor had added to a trailer intending to build his own camper, but gave it to my son instead. We put it up on 2 courses of cement blocks to make it higher, then added clear corrugated polycarbonate walls & ceiling on the S,E,&W, wih recycled plywood on the north, then lined it all with bubble wrap from Staples -- fairly cheap with free shipping. The north wall & ceiling have styrofoam insulation and then black tarpaper. I had an extra couple of small solar panels which I hooked up to old batteries, then ran a line into the gh so I can plug in an automobile-type blanket to cover the plants with on nights when it is supposed to go below 20 degrees. I guess it all helps, because temps in the gh haven't gone below 45 so far. I am very pleased! The 12Vdc power is important because I live on solar power and although I have plenty of AC electricity for the house, pumps, etc., don't have any extra for the gh. In my barn, I use regular heating tapes from the hardware store, which use amazingly little AC electricity, to wrap the water pipes with. I am wondering why they wouldn't help with greenhouses where you do have AC electricity? I planted various lettuces in the gh and it is all 4 inches high now, I am starting to pick a little to eat. I also have 4 pots of geraniums that are starting to bloom -- in the summer they are on my deck outside -- plus a small fig tree that is leafing out beautifully.

IMO, water is useful only if your temperature range extends to the phase-change temp of water (freezing - 32F) but it is pretty much useless if you want to keep your GH consistently above that temp.

I did a series of experiments in my own GH and what happens is as follows: The water warms up as the temps rise. But as soon as the temperature differential favors loss of heat, that is, as soon as the air temp drops below the temp of the water, then they start to cool off. By the time your air temp has dropped to your set minumum, the point when you need the heat, most of the heat has been lost from the water containers. This is especially true if the containers are small. In this circumstance, they are not worth the room they take up. You are better off just heating a smaller greenhouse.

An active system using pumps is different...this system is probably more efficient.

If your GH is allowed to drop to the freezing point, then the circumstances are also different. The latent heat released by the freezing water will indeed keep up the GH temps. Shane Smith has anecdotes in this regard in the book.

Has anybody tried to use solar power to heat their green houses? Surely, it wouldn't be as costly as powering an entire home?

The storage devices (batteries) make using solar to heat a greenhouse cost prohibitive. You have to collect the solar energy all day so you have it to run heaters all night. That means batteries to store the energy.

My husband built me a 10' X 22' out of cement blocks & old storm windows, attached to the house 15 years ago. We buy a hundred pound tank of propane & use that. It lasts 2-3 weeks. $ 62.00 per tank. See attached. We do keep the greenhouse at 55 degrees.