Let’s say your thumb isn’t exactly green. Let’s say it is, in fact, more gray or black than anything. That’s OK. You, too, can still have a gorgeous garden by following the USDA’s planting zones.

What are planting zones?

The USDA Plant Hardiness Zone map helps gardeners determine which plants are more likely to thrive in a given area. It’s based on the average annual minimum temperatures, divided into 10-degree zones. You can type your ZIP code into the USDA website and find exactly what zone you are.

The latest USDA map was created in 2012 and represents a change from the previous 1990 version.

The newer version of the map is generally one five-degree half-zone warmer than previous versions throughout the United States. Partially, the USDA says, this change comes from more thorough and sophisticated climate data that improved the accuracy and detail of the map.

Factors in the zones

Though the map is categorized by minimum temperature zones, the USDA also took into consideration other factors. These include light, soil moisture, duration of cold weather and humidity. Also bear in mind that the map covers the entire country and while accuracy is better, it still isn’t precise for any given area. The map is based on averages, not the lowest or highest temperatures ever, and your more delicate plants may still need to be protected in extreme weather.

Likewise, if a new version of the map comes out and you switch zones, that doesn’t mean you need to rip out all your existing plants. What’s doing well in your yard will likely to continue to do well, as specific plants may develop hardiness to different conditions over time.

Get experience

The best thing you can do to keep your plants alive, in addition to consulting the map, is to get more gardening experience.

Start by asking the experts at your local nursery what plants would do best in your area. Take note of the light exposure in your garden, any specific pests you have to battle, and be honest about your gardening experience and the amount of effort you’re willing to put in.