You have alot of loaded questions in this post. First, let me just restate what is often not well related about "UNHEATED" greenhouses. They will all usually have an inside air temperature equal or only slightly higher than the outside temperature by night's end. Even those who use various heat sinks have found that by the next morning their reserve heat is gone. This isn't to state that all the insulations and heat conservation methods aren't great. You will need much less supplement heat (if any, depending on crop) than you would otherwise. When the sun comes up everything is different. The temperatures inside will likely get too hot even in the middle of winter on a very sunny day. Some way of ventilating that heat without introducing a cold draft onto your tender plants is important. I've grown cilantro in PA overwinter without any heat. I think it is only slowed in growth by frosts. Parsley would probably be similar once you get it started. We have cut parsley in December although regrowth is much slower then. Basil is a different crop. It won't do near as well if you have cool nights. Leaves on established plants may discolor if temperatures drop near 40F. It is a sensative annual. In my opinion you could grow the cilantro, parsley and a host of other greens and eliminate the expensive heat. Since parsley is a biennial try to isolate it so it won't interfere with other planting practices. I would wait for warmer weather to grow basil.

brow, I don't know what zone you are in there, but most vegetables won't germinate until it's predictably warmer (including at night), it won't hurt to wait a few weeks if you are in an odd weather pattern. You said it's freezing at night, how about your daytime temps....Freezing at night with days as high as low 50's isn't going to encourage much of anything to germinate....that would make you averaging about 40 and cold enough for winter sowing of perennials, trees, shrubs. I'm usually seeing forecasts for Boise at least on NWCN but have not been watching for the last few weeks. Often makes me envious, Boise seems to have exceptionally nice weather compared to my coastal gray.

I don't envy you the snow, golddust. Had enough of that this winter to last a looong time. Since I first posted this it's the same as cyn427 says, where's the refreshing 70 degrees days? We hit 83 today. Sun is setting and it's still 74, feels like a mid-summer evening. Everything is busting open! I am concerned about my hydrangeas (among my favorites). The rarer ones are overwintered in the garage, so if we have a cold snap they can go right back inside. But the ones in the ground are all leafing out like crazy. It's usually mid - late May before I can tell which stems are going to have leaf buds and which died off and I can cut back. Hopefully no cold snap will freeze them, because they're all looking good this year! The other morning I checked peonies, stems were about 2" high max or just coming through. Came home end of day and many were easily at 6", unreal! I'm glad to have it, truly, but have a hunch this means we're headed for a pretty hot summer. As much as I love being outside, I just can't handle working in high humidity and heat anymore.

Thanks, everyone, for the input, and the suggestion to post the recipe...here it is: Make your favorite graham cracker crust for the springform pan--(EDITED TO ADD: use a 9 inch springform pan -- thanks for catching that Linda!) Cheesecake: 32 ounces of cream cheese, room temp 1/3 C of regular white sugar (and) 1 + 1/3 C more of regular white sugar 1⁄4 C of cornstarch 1 T vanilla 2 eggs, room temp 3⁄4 cup whipping cream (not whipped yet, just the cream as liquid!) Put 8 oz of the cream cheese in a bowl and add 1/3 C of the regular white sugar and the 1/4 C of cornstarch and beat on low until creamy. Should take about 3 minutes.... after it's creamy, beat in the rest of the cream cheese. After it's all mixed in, move the mixer to high and add the rest of the sugar (1 1/3 Cups) and the vanilla. After this is incorporated, slowly beat in the eggs, one at a time, making sure you beat after each egg is added. Slowly add the heavy cream and mix until just blended. Don't overmix. Pour the filling into a prepared springform pan (you've already made the graham cracker crust), and wrap foil around the bottom of it. Then, place the foil-bottomed springform pan in a larger pan and add hot water so the water comes up about an inch from the bottom of the cheesecake pan. Bake about an hour at 350 degrees. The center should have a tiny jiggle to it. Carefull remove the cheesecake from the water bath, remove the foil, and cool the cheesecake on a rack for about an hour. Put in fridge for 4 to 6 hours, or overnight, then remove the springform pan and get ready to serve.