Climate

The climate of a particular region is based on annual average high and low temperatures, annual rainfall, and the number of frost-free days. Wind and altitude are modifiers. Linnaeus said that altitude is more in accordance with the habitation of plants than latitude or longitude. This is backed up by research that found that plants growing in alpine regions are similar in different parts of the world, whereas plants growing at the same longitude or latitude are often different.

The USDA has generated climate maps that divide the country into zones based on climate. The United States National Arboretum Web site listed in the Further Reading section has an interactive USDA Plant Hardiness Zone Map that you can access to determine the zone for your region. It also provides information on how to choose perennial plants that will survive the winter in your area.