My Chicago Garden

yeah! NWS forecast was off by at least 2 degrees, maybe as much as 8 degrees. My home weather station reported a low of 40 during the overnight. The forecast for the next 7 days has temperatures in the low 40s in the evenings so we should be good to go for another week at least. That will push us past the average first frost date of Oct 15th. Awesome!

The great folks at the National Weather Service are forecasting 38 degrees across the Chicago area but the computer model point forecast is showing 35 degrees tonight for Wheaton.  Ouch! That’s one degree below their 36 degree cut off for frost. That’s a good 3 days ahead of my planning, but well within the high average.

I think I might cry.  The good thing at least is that no frost advisory is out. Which I hope means they are confident the temperature won’t go below 36.

Due to my day job being so busy I haven’t been getting home until after dark most days this week so I haven’t had time to finish the cold frame! That and the mature tomatoes plants still have 10 or 15 green tomatoes on them! Oh the humanity! I could pick them green, but as the graph below shows, the weather is going to go up following this single overnight low.  Decisions, decisions. I just can’t convince myself to harvest the tomatoes before their prime when it’s a one night chance. I guess I’ll take the risk.

*Images built using Wx for the Mac

I can only hope and pray that the NWS folks are wrong by a few degrees…in my favor.  If they are wrong in the downward side this could be the first frost of the season. 3 days early on the average. *sigh*

I probably could have built the cold frame in one weekend but I wasn’t dedicated to doing it. I came very close though.  The materials were obtained from Menards (have I mentioned Menards completely out classes Home Depot and Lowes by orders of magnitude?)

First I had to reduce the size of the 4×8 raised beds down to 3×8 so the windows would fit.  Not a big deal since when I made the original raised beds back in spring I used cheap pine boards and they were already rotting out so they wouldn’t have lasted anyway.  They are now made of cedar.

The major support pieces, the window units and anything that touches water or ground is built from cedar.  The wall material is 1 x 8 carsiding and will be painted with a 25 year exterior grade flat white paint.  Total material cost, minus the window glass, was about $150.  That’s pretty darn cheap if you ask me.  Especially for a 3 by 8 foot raised bed and cold frame that you can build yourself!

I’m thinking of insulating the walls with 1 1/2 inch foam.  Which should give an R7 or better insulation value.  If I can find Polyurethane or foil faced Polyisocyanurate the R value would be closer to R11. The single glass is going to be the biggest heat loss area.  With only an R value of about 1.  So I’m not sure if it’s worth the extra effort of foam. I may just wait until after this first winter so I’ll have some actual temperature measurements within the cold frame.

I still need to finish off the side panels and figure out a method of securing the windows to the frame in a way that secures them in the snow and wind, but I can take them off in the spring and summer.

I did some basic math and measurements and some architectural type drawings and figured out that a greenhouse would just not work…at least like I had been thinking. So I went back to the cold frame plans.

I remembered I had a book called “Four Season Gardening” that had some plans for a cold frame so I tracked it down in our library of books and read the chapter again. I’ve settled on building a “Dutch light” of sorts. Basically I’m taking 4 storm windows, and building 4 removable window units out of cedar. Then I build up a box around the one raised bed and lay the window units down on top. Couldn’t be simpler. I went to Menards tonight and picked up 2 lengths of 2×2 cedar. Cut to the correct lengths it makes the frame on to which to screw the window. I also noticed some tongue and grove cedar boards that I plan on using to build the box.

I need to resize the raised beds down to 8 x 3 instead of the current 8 x 4 so the window units fit correctly, but I didn’t like the width of 4 feet anyway. It was just too difficult to reach in and do anything in the middle of the beds. So no loss there. I’ll simply have 3 8×3 beds instead of 2 8×4 beds. All in all, I’ll gain growing space.

I know what my saturday project is!

Oh yeah…garlic came today from seeds of change. If I can get the cold frame built on Saturday and Sunday maybe I can plant them late sunday afternoon.