It is imperative that you check your hardiness zone before you start buying plants. This is especially important if you are in a colder portion of the US. These are calculated from average annual low temperatures for each zone. The temperature will not always hit these lows in a given year, but since they are likely to occur it can result in plant fatality in a cold year if the species or variety is out of its recommended zone.
Another consideration is whether the chosen plant will prosper in a given location. For example, a pear variety may survive in a locale but remain stunted and weak. A grape may grow well but its fruit never properly ripen. Colder zones can be expected to have a shorter growing season as well as simply be colder overall.
Be strict when planting, especially if it is a higher number, and when you are counting upon success for business or real homesteading. There is nothing wrong with pushing the envelope with a plant or two for fun, but don't gamble when the outcome is important.
Use this map as a general guide. If your land is in located at a high altitude, near a large body of water, or in another unique curcumstance, your zone may be altered. Look at local and state zone maps to fine tune your research.
