If you are plant lover, you know that selecting plant that suit your climate zone might play a major role to success. One of the first criteria to be considered before choosing a plant is their hardiness zone.
“Hardiness zone”, “ planting zone” or “growing zone”, all these phrases might seem confusing. At its core, hardiness zone is a scale defining 13 US zones based on the minimum temperature calculated in a 30-year period. For years, it has been adopted by planters to simply determine whether a plant can survive the winter in a certain area.
Hardiness zone 3 cover the majority of Alaska and some far northern states of US. Average minimum temperature fluctuates within -40 to -30 degree Fahrenheit. Due to highly continential climate, this portion of US land experience some of the coldest winter, high wind and low moisture. The long winter with temperatures falling below freezing point make it difficult to cultivate most plant.
Zone 4 expand over the southern coastal land of Alaska, northern and some highlands. The vast coverage results in different climates: some mountainous states like Wyoming has dry and windy weather, others present a more humid condition. The average minimum temperature in zone 3 range between -30 and -20 degree Fahrenheit.
Typical states in zone 3 & 4: Minnesota, North and South Dakota, Wyoming, Wisconsin
The long and extreme winter limit the plants options for growers. Some hardy succulents for zone 3 & 4 include Sedum Stonecrop and some Sempervivum genus such as Sempervivum Red Lion and Sempervivum Mahogany.
The hardiness zone 5 include the outer rim of Alaska, central US mainland and a portion of New York and Pennsylvania states. Featuring a minimum temperature of -20 to -15 degree F, these areas often experience moderate cold winter. Compared to zone 3&4, the variety of environments ranging from coastal climate to plains and woodlands facilitate the propagation of a greater number of succulents.
Zone 6 features a fairly pleasant weather with minimum temperature from -15 to -10 degree F. Cold weather combined with a mild summer, there are a lot more plants choice for growers.
Typical states: New York, Pennsylvania, Colorado, Nebraska, Ilinoiis, Idaho, Missouri, Ohio, Kansa, Utah
Most Sempervivum and Sedum can actually survive in zone 5 & 6 thanks to their low maintenance and hardiness.
As the USDA system is based entirely on average minimum temperature in an area, its ability to describe the climatic conditions is limited. In other words, a gardener may have to account for numerous other reasons to determine whether or not a given plant can grow well in a given zone.
Also, regardless of genus, you should never put your succulents in freezing temperature. Preparing for your succulent when winter fall is essential to keep them in healthy state, especially if you live in cold zone 3-5.