What does Hardiness (GH) mean?
Hardiness refers to a plant’s ability to withstand cold and/or heat, but this is actually an oversimplification of a complex topic. While a plant may be hardy enough to survive in a particular geographic region, it may not do so for any number of reasons.
More Info on Hardiness (GH)
Hardiness is an indication of a plant’s ability to survive in temperature or moisture extremes. It is a genetic trait of the particular plant type, and can be passed from parent to child, and can be copied through cloning and the creation of hybrid plants. One of the handiest tools a gardener has access to is the USDA’s hardiness zone map, which shows the relative hardiness zone for areas throughout the country. This can allow gardeners to make a more informed decision about the plants they bring into their outdoor gardens.
However, it is not necessarily as simple as comparing the specified hardiness zone on the plant’s label at the nursery to the USDA map. There are many other factors at play. For instance, our regions are made up of microclimates, which is why one hardiness zone often has one or more sub-zones. These are areas where temperature, humidity, rainfall and other factors vary considerably from the norm throughout the wider region.
Soil quality and health is another significant consideration. For instance, two plants in the same hardiness zone, with the same access to water and sunlight would be assumed to grow at the same pace. However, if one is planted in heavy, clay soil with little organic matter in it, and the other is planted in well-prepared soil, rich in organic matter and microbes, the latter will grow larger and stronger than the first.
Hardiness is an important factor when choosing plants for your garden, but there are other factors equally as important.