Oklahoma spans USDA Plant Hardiness Zones 6 through 8, with more specific zones including 6a, 6b, 7a, 7b, and a small area of 8a in the southeastern part of the state. The zones reflect average minimum winter temperatures, with zone 6a being the coldest (-10°F to -5°F) and zone 8a the warmest (10°F to 15°F)
. Recent updates to the USDA map show a warming trend in Oklahoma's zones, particularly along the southern border where much of the area has shifted from zone 7b to 8a. For example, Tulsa is now classified as zone 7b, indicating average annual minimum temperatures between 5°F and 10°F
. In summary, Oklahoma's zones range approximately as follows:
- Northern and central parts: Zones 6a, 6b, 7a
- Most of the state: Zones 7a, 7b
- Southeastern edge: Zone 8a
These zones help gardeners and growers determine which plants are most likely to thrive in their specific area of Oklahoma
