I have a 6x8 palram to extend the season. I will be using a solar water heater to create a moderating mass once the temperatures stay above freezing. I do not know of any practical means to heat a small greenhouse without electric or fossil fuel during extreme cold periods.

I have a cedar ridge heater which will be started February 18th. Just because I am already tired of winter! !

I have a 6x8 palram to extend the season. I will be using a solar water heater to create a moderating mass once the temperatures stay above freezing. I do not know of any practical means to heat a small greenhouse without electric or fossil fuel during extreme cold periods.

I have a cedar ridge heater which will be started February 18th. Just because I am already tired of winter! !

Thank you very much for the advice. I am tired of winter as well. This year I will only be "seed starting" annuals in there and moving them out to the garden the third week of May. I am going to try some big 5 gallon sparkle buckets wrapped in black garbage bags to keep heat Ina little. Who knows if it will work but it's cheap and easy. Any advice on when it would be safe to start seeds in there unheated? Last frost date here is May 21st. Thank you!!!

My green house is 12x16 and I do have power going to it. I recently covered it with a clear solar pool cover which makes a Huge difference. It maintains the night temp. by an extra 10* cutting down my heating bill.
There are several good forums here on bubble wrap and solar pool covers. You might want to check them out.

Hans

Another note: A lot of people are using vent free propane heaters, no electricity needed. Think they are called Big Buddy heaters, found at most big box stores.

Hans

If you want to keep individual plants warm at night, you can cut the bottom off of a clear juice jug and, after taking off the cap for ventilation, set the jug right over the plant. I did that last year, and also put some sawdust/wood shavings around the jugs. This was inside my greenhouse, I wanted my plants to get warmed up. I live in the Upper Peninsula, it's usually 50 degrees here at night in the summer.

SORRY , Upper Peninsula,

of what??

People make statements here and I gues you are supposed to read their minds as to what they are talking about.

This may be a duplicate posting as the first one disappeared. Anyway, the Upper Peninsula is part of the State of Michigan. It runs along Lake Superior, which divides the Upper Peninsula of Michigan from Canada. Canada is the country that is north of the United States of America. Both sections of Michigan are peninsulas. Hence, Upper Peninsula and Lower Peninsula. They are divided by the top part of Lake Michigan, which is crossed by using the Mackinac Bridge.

Hope that helps.

I'm in Northern Wisconsin not too far from Lake Superior as well, I have a small green house, unheated. I do not intend to run Electricity to it at all. In the dead of winter I have found that water barrels do NOT work...frozen solid....for weeks on end there is little to no sun shine. I am IMPATIENTLY waiting for spring. I did find that lining the structure with bubble wrap helps with day time temps, but not at night.adding a mini greenhouse ( well, a jumbo ziplock tote) brought up temps 10 degrees F, so adding layers of protection helps. Short of heating the structure, there is no way to sustain life in mine during winter. I plan on using mine for Tomatoes and peppers during summer.

I just got a Big Buddy LP heater from Amazon at $119. Saw a lot of good reviews on it. I do have a 240 volt electric heater costing me an extra $60/month to keep it up to 48*. The big Buddy claims to heat at low for 220 hrs or 18, 12 hr days, on a 40# tank. You can run it's fan on 4 batteries but I bought an adaptor since I do have electricity. I figure if it keeps it at about 55 for 18 days at $18/ fill up it will be worth it. I will keep track and see what happens.

Hans

6B-Coastal Massachusetts/I successfully overwintered tender perennials and hardy annuals in my unheated glass greenhouse. I did have them sitting on propagating heat mats, and at night and during sunless, cold days, I covered the benches of plants under blankets made from bubble wrap, which i tucked in to hold the heat. I only lost a few succulents in one of the coldest winters on record here. Nightime ambient temps were at times 10-15 degrees farenheit, and even a few subzero stretches of subzero days, when i also added blankets and quilts to the "tents". I was able to keep the soil temps at or above 32degrees. I even kept a maiden hair fern going all winter with this system, and though it seemed to be dormant, it has perked up nicely, along with my fox tail ferns, which are all vigorously waking up.

I made the bubble wrap blankets by using packing tape to hold together the lengths of wrap, which I bought in 24" wide rolls at a big box store. In the middle of the blanket, I used a self adhesive "tarp zipper", the kind contractors use at building sites for egress, (8 bucks from Home Depot) which was 7 feet long.This allowed me to keep the pots tucked into bubble wrap, but when it was sunny, I could go out to the GH and simply unzip the tent to let air and sun get at the plants. The wrap insulated the roots, and helped to hold in the heat when i zipped them back up at night.

Right now, in addition to my container plants, I have flats of onions, spinach and lettuce seedlings also spending time in the greenhouse and they go into the tents at night. I have had to vent the greenhouse during the day as the March sun heats it up rapidly. The challenge now is to keep things from cooking during the day! As soon as our snowfall issues abate, i can hook up our hydraulic roof vents which will automatically vent.

In another ten days, I think it will be warm enough to move my flower and veg plants from the grow light in the cellar to the greenhouse. On cold nights, I can use my bubble wrap tents to keep them from freezing.

Kbrielle18, I have no clue how you are going to actually heat a greenhouse in winter with no expenditure of some kind of power.

There is something that might help though. Some on here have already alluded to it (covering house with swimming pool cover). I have not actually seen one of the HF greenhouses, but photos on here led me to believe the frames are constructed of aluminum that is a couple of inches thick. The plastic that is the cover is attached to the outside of these frames.

If you can come up with a way to attach a film of plastic to the inside of these frames...even something as thin as the plastic sheeting painters use to protect indoor paint sites will do...The air trapped between these two layers of plastic is actually the best insulation per inch that you can purchase.

You might even come up with a way to add a strip of wood to these metal ribs to extend the depth of the trapped air space, and that way you get added insulation.

I used this trick on my little greenhouse (it was wood framed, and I could just staple into it) and it saved me many $$ on heat and cooling.

Bill