First greenhouse I have waited 74 years for this believe it or not.Its a lean -to 8x15 x9 at the highest point .I live in NM zone 7 90s to low 100s summer 20s high teens winter. I have insulated around base lower 3ft and 8mm polycarbonate sides and roof and it faces south. I am not sure yet what i will grow but thinking cacti and succulent .My question is (1st of many) is a blue flame propane heater a good choice or is it bad for plants. My propane tank is close to greenhouse

Congrats on the greenhouse! I had to wait 73 years before I got mine. It's been so much fun! I love going to sit inside when it's snowy and cold outside.

I think it depends mostly on your altitude. We are at 6500 ft near Silver City. We bought one, and it had a safety feature that automatically turned it off when oxygen was low. It required manual re-setting to run again. It would only run for less than 5 minutes. We now use electric for the greenhouse.

We heat our home now with a wood pellet stove. It keeps the main areas warm, and the bedrooms much cooler.

hello Karen Im in Socorro 4900ft approx never thought of altitude thats a good point I think electric.What temp do you keep yours

We lived in Socorro in the 80's. We enjoyed it there! I think the altitude there would be fine for propane, but you should check to make sure.

I heat ours to 60F because I mostly grow tropicals. You could go much lower than that for cacti and succulents. If you carefully chose hardy ones you might get away without heat for the most part.

My 12x12 greenhouse has a solar collector loop charged with glycol that runs through a 400 gal. heatsink. The water in it gets pumped into the insulated thermal mass of the floor with a DC pump on a solar panel. For supplementary heat, I disassembled a three-element radiant patio heater and mounted the 500W lamps on the ceiling on a thermostat set at 45°F.

For severe cold (it can go to -40°) I have a small propane heater with an outdoor tank.

hello Chip -40 we are at 12 at the moment, that is killing me, just came in from cleaning horse pens. Subartic good name for zone 3.I just read your post again that is impressive. Good morning Karen I like 60F the idea of sitting out there in the winter sounds good. I think I will only need heat at night facing south it may get to hot in the day. I am putting in a small swamp cooler with fans .This greenhouse is on my bucket list so I would like to do it right first time. I wonder what the most popular plants people are growing in hobby greenhouses?

We live in a remote spot and there are frequent power outages, so the propane heater is my backup. It's hooked up with a hose to a portable tank outside.

I run it on the LOW setting, except when the power's out, when I set it to HIGH. My greenhouse has enough air leakage that there's never been a problem with it shutting down.

That looks like a good setup, Chip. My greenhouse has leaks too, but our air is just too thin here at this higher elevation.

Besides the tropicals I grow tomatoes, green onions and cilantro so I can have salsa ingredients handy.

Most owners of my dome greenhouse use it to grow fruits and veggies. I am a flower nut, so I like colorful flowers year round. I have mostly Plumeria, Hibiscus, Geraniums, and different colors of the Crown of Thorns.

I was wondering about using propane, kerosene, diesel, etc. I wondered if the fumes could have a negative impact on plants, I'd hate to use one in a pinch and kill everything I had started.


I was mainly thinking about a kerosene/diesel "salamander" style heater.

I'll join in on this one after I read it was 12 deg in Socorro. Karen, how is your weather I sure you got quite a bit of snow , if I got 4 in and 4 deg this AM and sitting at 18 now. I use electric heater in mine. It is set at 60 so am getting ready for a big bill next month with this cold front and snow.

binfordw said:I was wondering about using propane, kerosene, diesel, etc. I wondered if the fumes could have a negative impact on plants, I'd hate to use one in a pinch and kill everything I had started.


I was mainly thinking about a kerosene/diesel "salamander" style heater.

Yes, gas by-products, such as ethylene, will definitly affect your plants. The heater needs to be vented properly. Even then, some plants may still feel the effects.

Just been talking to my propane company and there advice being at 4900ft is not use propane especially if the greenhouse is tight. CO2 problems, heater shutting off etc ,there advice for my size GH use elect.

Well Karen I'm glad you answer me, saved me a lot of problems with propane.

Do you grow onions ,cilantro all thru the winter?

Yes, my tomatoes, onions and cilantro will grow all year if I keep planting so the cilantro doesn't bolt and leave me with none.

That will please my wife Karen

I love it, too!

plantmanager said:That looks like a good setup, Chip. My greenhouse has leaks too, but our air is just too thin here at this higher elevation.

I'm at 7800 ft./2377 m. Never had a problem. The heater has a catalytic element and doesn't give off fumes like a kero heater. The solar setup and the electric radiant lamps provide about 90-95% of the necessary winter heat. I don't light the propane heater 'til it hits -10°F or the electricity goes off. Our power is all from a solar array anyhow, but the system is grid-tied and doesn't work when the line power is off.

To use propane, get a vented heater that draws air from outside and has an exhaust vent. We heat our house with a Qudra-Fire vented fireplace insert and also use a Bosch vented demand water heater.

Good morning all. Now that i've decided on electric heaters, what type of heater do you suggest? Heaters with fans, heater with out, radiant ,do you hang them, put on the floor, or on the bench. Do you keep other fans running. I will only
need heat at night ,here in NM sun will over heat even in winter.

Reliability is a big factor to. Thank you in advance

My greenhouse is 8x16x10, so it is just about the same size as yours. I'm in Zone 6b. I have used an oil filled radiator type electric heater. It has a thermostat, is reliable, no danger of fire, and if I remember correctly, cheaper to run than most common space heaters. I keep it on the floor in the center of the greenhouse and have a 16" oscillating fan up higher to keep the air circulating

Most of the winter heat in my greenhouse comes from a solar collector/heatsink/thermal mass setup (details on the greenhouse pictures thread) and from passive water tanks. Got a three-element patio heater and took it apart, mounting the three 500W lamps on the ceiling with a thermostat, to warm the foliage rather than trying to heat all the air.

There are quite a few quartz radiant heaters available.

My greenhouse is heated in the same way as subartic's. As I am growing mostly orchids and tropicals, its pretty humid so I always have several small fans running to keep the air circulating. I try to keep the winter temperature above 55. My system works well enough so I only need an emergency backup when the temps are approaching 0. I use a cheap utility heater with a forced air fan sitting in the middle of the floor on the dry end of the greenhouse.

Most heaters now have a tip over shut off feature but you should always be using one with a grounding prong.