Covering the state's largest geographic area, 8a and 8b include Central Texas. The area from El Paso to Dallas-Fort Worth enjoys the benefits of 8a, while 8b covers the area from the Rio Grande through San Antonio and Austin to Nacogdoches and the state's eastern border. Average low temperatures in winter are between 10 and 20 °F. You may also be able to extend your plant options a little further than your area if your property includes microclimate areas at a different height or with more or less protection from the elements, resulting in slightly different temperatures and conditions within your property or general location. Once you've identified your area, read magazines, catalogs, websites and visit nurseries to find out which palette of plants will be the happiest in your garden.
This zone covers a strip that extends from the New Mexico border in western Texas to small sections of the eastern borders of Oklahoma, Arkansas and Louisiana. Experienced gardeners rely on plant information from the hardiness zone established by the USDA (United States Department of Agriculture). Zone 6b, in the northernmost part of the state, around the cities of Amarillo, Canyon and Hereford, averages 18 inches of snow per year. It's important to know your specific growing zone to ensure that the time you spend in your garden has the greatest chance of success.
As the second largest state in the United States, the Texas landscape includes four different USDA zones. Monitoring your gardening experiences can show that you can grow plants in slightly colder or warmer areas. Both Dallas (Texas) and Portland (Oregon) fall within hardiness zone 8a, but in Portland, the average number of days that exceed 90°F is about 15. Knowing your specific area can make the difference between losing plants that are less resistant to winter frosts and preventing them from frying in the extreme heat of higher areas. If your gardening wish list includes plants that aren't hardy in your area, consider planting them in containers that can be brought indoors during extreme winter.
Labeling and plant growth information are sometimes limited to “Texas,” making it difficult to identify which of the many USDA Texas areas are appropriate places for cultivation.