Bulb Climate zones/hardiness zones
The United States Department of Agriculture (USDA) in cooperation with the National Weather Service (NWS) has identified various regions within North America by their 60-year average minimum winter temperatures. These regions called hardiness zones or climate zones are represented by bands across the continent.
The same standards have been applied to Europe and other continents. Use the maps provided below to determine your climate/hardiness zone. Knowing your zone will help you find bulbs that are suitable for your climatic conditions.
When planning a garden, consider your local climate and the established ‘hardiness rating’ of various plants you have in mind. Some plants cannot handle severe winters; others wither in heat; still others, such as many spring-flowering bulbs, need a cold period to stimulate growth cycles. In our bulb explorer, you can indicate in which zone you live. Bulbs that don’t do well in your zone will be excluded from your search results.