A plant’s hardiness zone is defined as the amount of cold it can take before it freezes to death. It’s ability to survive blistering winters is directly connected to where and when it evolved. Tomatoes, for example, are native to Central America and can’t get through even the mildest winter in the US. So you have to plant them over and over each year. But, go to where they are native, and they don’t need to be started from seed annually. Likewise, Echinacea purpurea (coneflower) evolved in eastern North American with a hardiness zone range of 3 to 8. They can take lots of cold and relatively lots of hot. They will find it difficult to grow where tomatoes flourish as well as in the northern parts of Canada.
A hardiness zone map is easy to find. The one below is from the USDA and break each zone into an “a” and “b”.
Hardiness zones were first created for cultivating trees and shrubs during the first half of the 20th century. In the 1990s, the USDA began to publish the “official” maps. This makes sense because most vegetables are planted and harvested within the same year while fruit and nut trees need to stay around to mature. That’s why oranges are grown in warm climates and apples are grown in colder climates.
Hardiness zone is a fundamental especially for those wanting to create that beautiful new perennial look. There’s plenty of things it doesn’t tell you. The more you fall in love with gardening and landscape design, the more you’ll have to learn. Plus, there is no substitute for real-world experience. The hardiness zone don’t tell you how much or little water a plant will need or how much heat a plant can take. However, on the road to expert planting skills, knowing what hardiness zone you are planting in will do more good than harm.
More Posts about Winter and Colder Temperatures
Winter Gardening: Beauty in the After
Beauty in the After, the Series
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