Fortunately for the gardener who does not want to be totally
dependent upon the weather there are ways to extend the gardening
season and you can incorporate those ways into yoru garden plan.

A
greenhouse tops the list of ways that you can extend your gardening
season. However, you may lack the resources (space and funds) to build
one.

The next best way to create a longer
growing season is the use of poly film. You can uses black poly film to
warm the soil; suppress weeds and as a mulch. Your local plant nursery
is likely to carry a black, bio-degradable poly film that will do the
job. I have used this method several times over the years and have been
quite pleased with the results

poly tunnel photo courtesy flickr/mike warren