I also have an 18 by 18 exhaust fan and 12 by 12 intake louvers

Hi Jeff, I am in a similar situation. I have mangos, bananas, guavas, citrus, papaya, carambola, lychee, pitomba, pitanga, grumichama, gardenias, plumies, adeniums, etc, etc. 1. Anyone in similar circumstances? What GH did you get, and are you happy with it? For various reasons, my GH is 20x23 tempered glass. I really like it, but at times I wish I had twinwall PC...better insulation and wetfeet is right, better light diffusion. 2. I'll probably use electric heat, but what do you use if the power goes out? Are there gas/propane heaters that can kick on in that situation? You can rig a backup generator. Alternatively, you can use backup gas/propane, but you probably would either have to have them on a microvoltage thermostat with a pilot light, or you would have to fire it up on your own. The next question is whether to use a vented or unvented heater. Vented heaters will not cause any plant trouble, but unvented heaters might. For a raging debate on this issue, look back about 6 months in this forum (or just wait until it comes up again this next winter). I have tons (literally) of soil and rock which act as thermal mass, but I don't go out of my way to add barrels of water. I'd rather fill the space with plants, and my experience and experiments tell me that it doesn't make that much difference anyway. Email me if you want details. 3. Can you grow tomatoes, peppers, herbs? Sure. Peppers and herbs are easy. Tomatoes are harder...they like a lot of light and heat, they take up space, they attract whitefiles like crazy...for me, they don't produce well enough to make it worth the space in the winter GH. 4. I've read that ventilation is important, but do you really suck icy cold air into your GH? No. The way I do it, and the way many others do it, is to just use passive ventilation in the winter. So rather than having a fan drawing air through, you just have a roof or ridge vent open to let a little heat out. Minimizing infiltration is important, but you will want some winter ventilation to keep humidity down. Venting and reheating is an important method of controlling the VPD. When you get rolling, let's trade some plants! SB

I don't know if you do this, but I also start my plants in my garage during the winter but I use a heat mat on the table as it allows the bottom heat which plants need to germinate for me. You can purchase this online through Park Seed Company. I won't kid you, it has an expense to it as I also purchased a thermostat for it to keep the temperature consistent, but well worth the expense considering that everyone is out of plants except me and I can keep my business going this way. Carrots are not going to germinate in tight spaces such as an egg carton due to the tap roots needing more space. Those can be started in a gallon sized container. Some nurseries will give you a few if you ask them for their toss aways. I have seen nurseries throw away containers, trays and the like, just be sure to sterilize them before using them to pot your goods. Some seeds also don't want light until they just start to germinate. Read the package of the seeds to see if light is needed or if they need darkness. I know some herbs will not grow in light until germination like cilantro. Also, as crazy as this sounds, air circulation is important even in the wintertime. Keep a small fan (lowest setting) in the area to circulate any warm air to keep your plants from mildew and mold disease. Keep all soils moist but not wet during the first few weeks or until the seedlings have their second leaves and then reduce to watering in the morning and keep them in the sun and warm. I also have a growth light on a timer for night times when they need a few extra hours of light as winter gets dark sooner. This keeps my veggies happy a lot. Does this help?

I had no problems last spring with my tomatoes going direct from my GH to the garden. Most were about 12 inches tall or taller. The GH has a large swamp cooler blowing air when ever it got up to or over 85 degrees. High altitude Colorado bright sun. It could depend on the quality of the GH material. \