Növényzetzónák

Növényzetzónák, commonly translated as plant hardiness zones, are geographic regions that have a specific minimum average winter temperature. These zones are crucial for gardeners and horticulturists to determine which perennial plants are most likely to survive the winter in a particular location. The concept was first developed by the United States Department of Agriculture (USDA) and has since been adapted and modified by other countries and organizations.

The zones are typically numbered, with lower numbers representing colder climates and higher numbers representing milder climates. For instance, Zone 1 is the coldest, experiencing average minimum winter temperatures of -50 to -45 degrees Fahrenheit (-45.6 to -42.8 degrees Celsius), while Zone 13 is the warmest, with average minimums above 65 degrees Fahrenheit (18.3 degrees Celsius). Each zone is further divided into sub-zones, denoted by letters 'a' and 'b', indicating a 5-degree Fahrenheit (about 2.8-degree Celsius) difference.

When selecting plants, gardeners consult a hardiness zone map to find out which zone their area falls into. Plants are then labeled with the zone(s) in which they can reliably survive. Choosing plants appropriate for a given zone increases the likelihood of their successful overwintering and subsequent growth in the following seasons. Factors beyond just the minimum temperature, such as precipitation, soil type, and microclimates, can also influence plant survival, but hardiness zones provide a fundamental guideline.