Extend the growing season by making a cold frame. This is easier than you may think. A cold frame is simply an enclosed area with a top that lets in sunlight.
There are several ways to build a cold frame but the easiest is take an old window frame, with glass still intact, and lean it at an angle against a sunny wall. If you are feeling slightly more adventurous you could arrange four bales of hay or straw as the sides of your cold frame and lean the window against them. The straw can then be used for mulch next spring when you take the cold frame down.
Old window frames are often thrown out in skips or can be found on websites like Ebay and Freecycle.