Definition - What does Crop Zones mean?
Crop zones are geographic areas that are defined by climatic conditions, specifically minimum temperatures. Crop zones are mostly known as ‘hardiness zones’.
In each crop zone, a specific category of plant life is capable of growing, as defined by climatic conditions, including the plant's ability to withstand the minimum temperatures of the zone.
A plant that is described as "hardy to zone 10" means that the plant can withstand a minimum temperature of −1°C (30°F) to 3.9°C (39.0°F). Crop zones were first developed by the United States Department of Agriculture (USDA) as a rough guide to landscaping and gardening. In recent times, the use of crop zones has been adopted by other countries, too.
In controlled environment agriculture, growers need not worry too much about crop zones, as the plants are grown indoors and are protected from the outdoor climate.
MaximumYield explains Crop Zones
Crop zones (hardiness zones) allow a gardener to know instantly if a specific crop can grow and survive in the depths of winter in specific parts of their country. It is a standard by which gardeners and growers can determine which plants are most likely to thrive in a certain location. The map is based on the average annual minimum winter temperature divided into 10-degree Fahrenheit zones.
When a plant tag is labeled as “zones 3-7”, this means that the plant will survive in zones ranging from 3 to 7. Plants suitable for these zones can be killed by too much cold. Almost all plants have been assigned a hardiness zone. A point to keep in mind is that the zones with lower numbers have colder winters.
Recently, there have been some of the changes in the zones, which is a result of new, more sophisticated methods for mapping zones between weather stations. These new changes include algorithms that consider, for the first time, factors such as changes in elevation, nearness to large bodies of water, and position on the terrain, such as valley bottoms and ridge tops. Also, the new map uses temperature data from many more stations than the map from 1990 did.
These changes have greatly improved the accuracy and detail of the map, especially in mountainous regions of the western United States. In some cases, they resulted in changes to cooler, rather than warmer, zones.