Geographical Zones for Plants
Most gardening books will indicate in which zones a plant will fare best . You usually will find a map of zones in larger gardening books. Sunset has a good one. I recommend that you determine your gardening zone before you purchase any plant material, so you have a better chance of that plant surviving. Especially if you have severe weather patterns. Of course some areas have such moderate weather, that you can plant most anything.
This garden book is my bible and it has everything you need to know about plants for the western garden. Sunset also has books for other areas of the country, such as the East or Central part of the U.S.
I live in Northern California, and we have a somewhat Mediterranean climate. Gets down in the 30s sometimes in the winter and up in the 90s occasionally in the summer. I like to take precautions when the weather is extreme. I cover tender plants in the winter or shade them in extreme heat.
Of course, if you choose carefully, you can find plants that withstand almost anything.