If you’ve exercised your green thumb we’re sure you’re familiar with the term “hardiness zone” or “gardening hardiness zone”. But, what exactly does this all mean? Let’s explore.
A hardiness zone is expressed as a “geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone.” These zones, according to the USDA, are based on the average annual extreme minimum temperature during a 30-year period in the past, not the lowest temperature that has ever occurred or is predicted to occur.
So, how do you know which zone you’re in? The USDA has created a very detailed map outlining the US and how the zones are broken down. This resource is second-to-none when it comes to hardiness zones.
Once you determine in which hardiness zone you reside – and it is as simple as visiting the USDA map and clicking the mouse on your location – you can use this information to better plan your garden. Knowing your zone informs you of the following:
- When temperatures allow you to begin planting in regards to projected frosts
- What your average lowest temperature is
- Which plants best perform in your zone
It is also important to be aware that there are factors that will affect plant growth in addition to your hardiness zone. Consider the following to have a variable effect on your plant’s success:
- Moisture in air and soil
- Soil quality
- Light exposure