Warming your soil for early season crops

With a small vegetable and fruit growing area the key is to avoid a glut of crops at any one time and produce a steady flow of edible crops through the year.
In January early season crops can be started by using the suns rays to start to warm the soil using black plastic to collect the suns rays and start to warm the soil. Simply cover the ground with some black plastic making sure its pegged down or has a few bricks to weighting it down to stop the wind
Another method to warm the soil is to create some low plastic tunnels or cloches using some wire and plastic again to start to warm the soil for early season crops