What The USDA Growing Zones Mean

By Jannie Vaught

Have you ever wondered about the USDA growing zones and what does it mean to you as a gardener or a farmer?

Let us get a definition.

The USDA Hardiness Zone map divides North America into 11 separate planting zones; each growing zone is 10*F warmer (or colder) in an average winter than the adjacent zone. Zone 8 Texas is one of the zones in the United States. Like all zones, it is divided into two subsets.

These are zone 8a and zone 8b. The zone designation can help you select plants suitable for your zones’ cold temperatures. Each zone is separated by a 10*F temperature difference. This means that zone 8 is 10* colder than zone 9, and 9 is 10* colder than zone 10 and so on. Subset zone temperature. Each zone has two subsets. Each subset is separated by 5*Fahrenheit. That means Zone 8: The zone minimum average temperature is 10 to 20-degree Fahrenheit. Zone 8a: The zone minimum average temperature is 10 to 15-degree Fahrenheit. Zone 8b: The zone minimum average is 15 to 20-degree Fahrenheit. The temperature ranges in each zone and each zone subset are averages of the typical low temperatures you can expect. The temperatures can often dip below the average range during harsh winters or unusual weather patterns.

The USDA updated these in 2012, many zones were placed a half-zone higher than the 1990 map. This was due to newer technology and better weather mapping. So now we know what Hardiness Zones mean. So when your planning and designing your year-round garden you can find the seeds and plants that will grow and flourish in your zone. This is another up and down, fall heading into winter soon and one day it is 70 the next 40. I figure I want the plants that are the hardiest at the lowest temperature possible. And this year seems to be a home run for this gardener. Kale, mustard, and Broad beans are flowering and I cover very rarely.

Guess I’m finally paying attention to those pesky zones!

Growing green and paying attention with Jannie