Warming Up The Soil In February For March Planting

I've been reading about using black plastic over the garden soil for a few weeks in February to warm it up for planting seeds in March.  So, I thought I'd give it a try.   I used a large garbage bag, cut it down the side and across the bottom and spread it out.  Several landscape fabric pins will hold it in place.  I will be planting pea seeds and other cold crops in March.  I will do a test by planting in plastic-warmed soil and non-plastic-warmed soil.  We'll see if there is a difference!

landscape fabric pins 

black garbage bags

black garbage bags, cut open and placed on garden in February to warm the soil