We grow tomatoes in high tunnels.  What is a hightunnel?  It is a plastic covered hoop house that sits over the field.  It allows us to protect the young plants during the cold part of the spring. We are able to control the temperature inside by opening the sides, ends and a portion of the top.  The best way I can explain it to gardners is a larger scale version of the "milk jug over your tomato plant" trick.  Plants are grown in the same spot, in the same dirt, just with adjustable protection.  They are expensive and considerably more work than planting outside but worth it.

Below is a slideshow of our tunnels to give you an idea. (click play button on right side of picture to start)