Lubbock is in the northern part of Zone 7. Plants must be able to withstand sustained temperatures of 0 degrees to be considered hardy in the Lubbock area. However, soil, moisture, humidity, heat, wind, and other conditions also affect the viability of individual plants. In Lubbock, plants that are “hardy to Zone 7” but might not thrive due to the summer heat.
There are several sources of information on the soils in Texas. The place to start is the USDA-Natural Resources Conservation Service (formerly the Soil Conservation Service). They publish “soil surveys” for each county, in cooperation with state agencies. Check here for the status of soil surveys in Texas (you can also see it in map form). There are also soils data for GIS applications, found in the Soil Survey Geographic (SSURGO) Database, from the USDA-NRCS. Click here for a map showing the certification schedule of SSURGO data in Texas. If interested in SSURGO data, please go to the National SSURGO Database. You can also find specific information on Texas soils in the Texas Soil Characterization Database, compiled by Texas A&M University’s Soil & Crop Science Department. Maps and analytical information for over 100 soils can be found on the Soil Characterization Laboratory’s web page.