Zone 5a -20°F to -15°F | Zone 5b -15°F to -10°F | Zone 6a -10°F to -5°F | Zone 6b -5°F to 0°F |
Zone 7a 0°F to 5°F | Zone 7b 5°F to 10°F | Zone 8a 10°F to 15°F | Zone 8b 15°F to 20°F |
Based on the USDA Hardiness Zone Map, this interactive version covers the country of Bulgaria which ranges from Zone 5a to Zone 9a.