A hardinesszone is a geographic area defined as having a certain average annual minimum temperature, a factor relevant to the survival of many plants. In some systems other statistics are included in the calculations. To find the PlantHardinessZone at your location quickly, enter your zip code in the Quick Zip Code Search box in the map above, or click anywhere on the map to view the corresponding interactive map.How to Use the Maps. The legend of the planthardinesszonemap. Us Gardening Zones.TheUS Department of Agriculture (USDA) has released a new planthardinesszonesmap. To find out how this information affects your garden and your garden plans for the season ahead, read the article and save this Pin. Planting Calendar – Zone12. Step 1: Find your zone.Zone12 is hot, hot, hot! Located in Hawaii and Puerto Rico exclusively, this planting zone is best suited for tropical plants like pineapple, black pepper, mint and more. Similar to the planthardinessmap, the heat zonemap is made up of 12zones (the planthardinessmap has 13) based on the average number of “heat days” an area experiences in a year. Most gardeners are familiar with theU.S. Department of Agriculture's PlantHardinessZoneMap. First published in 1960, with the current version updated in 2006, this map is based on average annual minimum temperatures recorded throughout North America. This is the official USDA PlantHardinessZoneMap. To find your exact area, use the garden zone by zip code tool.