Knowing your USDA hardiness zone can help you better understand what kind or variety of plant is best for you to buy, when to plant, what grows best in your climate, and how to better take advantage of your specific growing conditions.
The USDA Zone Map consists of Canada and the United States.
The Zone Map divides these regions into 11 different zones. The zones are arranged based on what is the expected lowest winter temperature, based on the climate average. The current Zone Map averages are derived from the winter averages of 1974 – 1986.
Know What to Plant
For you to accurately know what to plant, you must know your USDA hardiness Zone.
The Zone Map will help you decide if a plant will survive in your area as a perennial or an annual.
For example, If I am looking at a plant that is hardy in Zone 6 through Zone 10, considering the fact that I live in Zone 5, I know not to plant it outdoors in my area!
If your zone falls between the range stated for the plant, then the plant is hardy for your area. So this particular plant is also hardy or can be a perennial in zones 6, 7, 8, 9, and 10.
But a plant says that it is hardy to Zone 3, for example, then it will be hardy in every zone down to Zone 3.
If your zone is lower than the zone listed on your plant info, then that particular plant, tree, or shrub will not be hardy to your zone, and you will need to treat this plant as an annual.
For example, I’m in zone 5, as I said. If a plant says that it is hardy to Zones 9 – 11 that means that I will have to treat this plant as an annual here in Zone 5.
Once you know your zone, it becomes much easier to determine if a plant will be perennial and survive winters in your area.
How USDA Hardiness Zones Work
It is important to note that the zone map is based on the plant being planted into the ground.
It does not take into consideration your season extending greenhouses or covering.
Raised beds and pots will also be cooler than the ground and are more likely to freeze.
So also take this into consideration.
Plants are less hardy in a container or raised bed than they would be in the ground. If you are planting in any kind of raised bed or container, you will need to decide upon a plant that is hardy to at least two zones less than the zone you live in. For example, if I am planting in pots outside, I need to select plants that are hardy to Zone 3 and under – those few very hardy plants that can handle a hard freeze.
If you are moving towards a more sustainable, lower maintenance, perennial edible garden it is imperative that you know your zone, the zone tolerance of the plant, understand how the USDA hardiness zones work, and plan accordingly to these details.0