Your University of Missouri Extention has a wonderful list of documents. http://extension.missouri.edu/xplor/agguides/hort/

Under vegetables. :)

Here is a link that might be useful: Univ of Mo Ext

I use 10 foot poly pipes (1/2 inch) across my 3 and 4 foot beds and push the ends about 6 inches into the soil. I haven't tried greenhouse plastic, just painter's dropcloth plastic that is 10 feet wide. I clamp it onto the pipe with bullnose clips, and weigh down the edges with boards, rocks, whatever is around. In the spring we have very high winds, so I tend to go for overkill. When I reach into the tunnel, I either lift one side or open the end.

As you say, I have had success with spinach and kale (which is MUCH better after a touch of frost than in the summer). I just use Bloomsdale spinach. I've also had good success with carrots, turnips, and radishes. This year I am trying Brussels sprouts (planted in the spring for fall/winter harvest) and a couple of kinds of chicory in my tunnel. I also plant lettuce and beets, but those don't last past Thanksgiving here.

Your timing is probably fine. I've been moving my own planting back every year that I have planted a fall/winter garden. Although I am also in Zone 5, I live on a mountain side and our nights are already in the low 50s That makes for slower growth, so I have to plant a earlier. I got most of my seeds in this week, although I put kale and Brussels sprouts in earlier because the need a longer season. I have one more bed to finish, mostly with carrots and radishes. My kids made it clear last winter that we didn't have enough carrots!

Hope some of this helps. Good luck with the garden.

Catherine

Its almost impossible to grow anything in the midwest in the winter. You can try indoors though

Here is a link that might be useful: Growing Winter vegetable gardens