Classification Based on Hardiness (Adaptation)

Plants can be classified according to their hardiness or adaptation to local climate. Certain trees are able to thrive under cold temperature, whereas others prefer warm or tropical conditions. The U.S. Department of Agriculture (USDA) Plant Hardiness Zone map divides the United States into 10 zones. A zone 1 is the coldest, and zone 10 is the warmest. Plants' adaptive ranges may be narrow or broad. For example, a shrub such as cinquefoil (Potentilla fruticosa) is adaptable to zones 2 through 7, and lantana (Lantana camara 'Nivea' L.). is adapted to zones 9 and 10. All plants may be placed into one or more of these hardiness zones.