ZONE 10. High Desert Areas of Arizona, New Mexico, West Texas, Oklahoma Panhandle, and Southwest Kansas
Growing season: April to early Nov. Chilly (even snow-dusted) weather rules from late Nov. through Feb., with lows from 31 degrees to 24 degrees F/-1 degree to -4 degrees C. Rain comes in summer as well as in the cooler seasons.
ZONE 28. Gulf Coast, North Florida, Atlantic Coast to Charleston
Growing season: mid-Mar. to early Dec. Humidity and rainfall are year-round phenomena; summers are hot, winters virtually frostless but subject to periodic invasions by frigid arctic air. Azaleas, camellias, many subtropicals flourish.
ZONE 29. Interior Plains of South Texas
Growing season: mid-Mar. through Nov. Moderate rainfall (to 25" annually) comes year-round. Summers are hot. Winter lows can dip to 26 degrees F/-3 degrees C, with occasional arctic freezes bringing much lower readings.
ZONE 30. Hill Country of Central Texas
Growing season: mid-Mar. through Nov. Zone 30 has higher annual rainfall than Zone 29 (to 35") and lower winter temperatures, normally to around 20 degrees F/-7 degrees C. Seasonal variations favor many fruit crops, perennials.
ZONE 31. Interior Plains of Gulf Coast and Coastal Southeast
Growing season: mid-Mar. to early Nov. In this extensive east-west zone, hot and sticky summers contrast with chilly winters (record low temperatures are 7 degrees to 0 degrees F/-14 degrees to -18 degrees C). There's rain all year (an annual average of 50"), with the least falling in Oct.
ZONE 33. North-Central Texas and Oklahoma Eastward to the Appalachian Foothills
Growing season: mid-April through Oct. Warm Gulf Coast air and colder continental/arctic fronts both play a role; their unpredictable interplay results in a wide range in annual rainfall (22" to 52") and winter lows (20 degrees to 0 degrees F/-7 degrees to -18 degrees C). Summers are muggy and warm to hot.
ZONE 35. Ouachita Mountains, Northern Oklahoma and Arkansas, Southern Kansas to North-Central Kentucky and Southern Ohio
Growing season: late April to late Oct. Rain comes in all seasons. Summers can be truly hot and humid. Without arctic fronts, winter lows are around 18 degrees F/-8 degrees C; with them, the coldest weather may bring lows of -20 degrees F/-29 degrees C.