A Cold Frame for the Raised Planter Box

I made an elevated planter box back in March 2013 (hard to believe that's almost a year ago!) to go on our front porch.  We planted some spinach back in early October to see if it'd produce anything and while we haven't gotten any spinach out of them, those things are still hanging on even through some pretty nasty cold weather.  An idea came to mind about a month ago to try to make a cold frame cover for the box.

I wasn't sure what to do for a while.  I considered making row cover tubing out of PVC, but didn't like that the elevation would be constrained around the sides of the hoops.  I also had done some reading about creating shade for cooler weather plants to try to grow them in warmer weather. I needed a means of providing that shade even though that box gets filtered sun from a large maple tree next to the house.  In the end, I decided to make a frame out of 2x2's purchased from Community Forklift that is designed to be tall enough to accommodate lettuce greens.  I will, of course, remove the cold frame plastic once the weather warms up.

Because this was my first of two raised planters I made, I made some mistakes. Most notably, I didn't allow enough room in the leg slots for the box-side wood to swell.  That led to the one-by side pieces raising ~1/2" above the top surface of the legs as well as swelling and width-wise creating cracks in the legs.  You can see some of the results of the swelling in the picture above.  I used my circular saw to cut those side pieces flush with the leg tops.

All in all, it was a good Saturday project and will, hopefully, allow us to have a productive spring crop.  I'm anticipating lettuce and radishes.