The problem i have is with voles. I'm sure the solution is the same but before i do all that work i'm going to try keeping the foundation clean, plus keeping the interior free of places they can hide. Poppa

Hey tmc2009, looks like a good start. I don't know how well the block foundation will work for heat retention, but building a sturdy foundation for these things is never a bad idea, in my opinion. Interesting about the old house or barn foundation you uncovered during the excavation. We enjoy discoveries like that too, although we have never had the pleasure of owning a property inhabited as far back as yours. I'm just finishing loading my 10x12 for the winter (still cramming plants in with a shoehorn.) It's not cold here yet, but it takes me a long time to get everything situated cheek-to-cheek on and underneath the benches. Hope your build goes well. Here is a link that might be useful: Building our Harbor Freight 10x12 Greenhouse

I can use them for other white oaks, Ken. I'm going to take a new path to see how they will sell on Craigslist and Ebay and most-importantly, if they will stay alive thru these insanely hot summers we've been having. I can't keep my conifer grafts alive. It's pointless. Ireena, in the ground is the best way. Plant (3) per space and select the strongest seedling the following year. Be sure to cage where your trees are so you know where and to keep rabbits and deer from eating them. (3) per hole also may keep squirrels and other animals from removing all per spot. Ken, I also planted many other oak species, along with: hickory, magnolia, sorbus, pecan, etc- and I am going to plant several of everything on the property that adjoins mine. And, I will plant them all around the valleys here too. Dax

I have a 9x12 greenhouse. It is attached to our home where a Bilko door would normally go over the outside basement steps. I just want to keep things from freezing. I have tender pond plants in tubs in it. I have double glazing, it is the fiberglass sheets that are double layer with "I-beam" construction. The ends of the fiberlass sort of look like corrugated cardboard. I used normal house windows that I got cheap and aluminum storm windows. I heat it with an electric shop heater or garage heater. They mount on the ceiling or a wall. Mine from Lowes has a light built in so you can tell when heater is on. I installed a normal home electric heat thermostat that switches the outlet where the shop heater is plugged in. In extremely cold weather I also use kerosene heater. You could use your propane heater and back it up with electric and an audible alarm that comes on when the electric heat comes on or just look out to see if the light on the heater is on. When I built the green house I dug the foundation 2' deep. Then I laid a concrete block foundation. I used solid blocks on the bottom and then regular blocks on that. I didn't use any mortar below grade thinking that I wanted moisture to be able to flow. I placed the block against each other. I had a watering system and was trying to let the moisture that went down on the ground escape easily. When I dug the foundation, I got enough stone that I was able to make the above ground part of the foundation out of mortar and stone. There is not a single crack in the mortar despite the fact there is no mortar below grade and I built it over 30 years ago. The most important part of a green house is ventilation and cooling. They will cook anything. I have an air-conditioning thermostat to control a vent fan. The vent fan is for a barn and has louvers that automatically open when it is on and close when it is off. Mine draws air from the basement when the fan goes on. Yours would need some source of air like another louvered vent.