Plant Hardiness Zones
Lawn & Garden · 10 specs
Direct Answer
The USDA Plant Hardiness Zone Map divides North America into 13 geographic zones based on the average annual extreme minimum winter temperature in 10°F (-5.6°C) increments, subdivided into 5°F 'a' and 'b' half-zones to determine plant winter survival.
Source: USDA Agricultural Research Service (ARS) / PRISM Climate Group · Last reviewed Aug 28, 2026
Specs
| Governing Standards | USDA Plant Hardiness Zone Standard (1990–2023 30-Year Normals) |
| Zone Temperature Increment | 10°F (5.6°C) per main zone number | 5°F (2.8°C) per 'a' and 'b' half-zone |
| Zone 3 (Extreme North) | -40°F to -30°F (-40.0°C to -34.4°C) | Birch, Spruce, Haskap berry |
| Zone 4 (Northern Cold) | -30°F to -20°F (-34.4°C to -28.9°C) | Sugar Maple, Honeycrisp Apple |
| Zone 5 (Upper Midwest / NE) | -20°F to -10°F (-28.9°C to -23.3°C) | Oak, Dogwood, Lavender |
| Zone 6 (Mid-Atlantic / Midwest) | -10°F to 0°F (-23.3°C to -17.8°C) | Boxwood, Peach, Hydrangea |
| Zone 7 (Transitional / South) | 0°F to 10°F (-17.8°C to -12.2°C) | Crape Myrtle, Fig, Magnolia |
| Zone 8 (Deep South / PNW) | 10°F to 20°F (-12.2°C to -6.7°C) | Rosemary, Camellia, Oleander |
| Zone 9 (Subtropical South) | 20°F to 30°F (-6.7°C to -1.1°C) | Citrus, Avocado, Hibiscus |
| Zone 10 (Tropical / Frost-Free) | 30°F to 40°F (-1.1°C to +4.4°C) | Bougainvillea, Mango, Banana |
USDA Plant Hardiness Zone Temperature Matrix
| Zone Classification | Minimum Winter Temp (°F) | Minimum Winter Temp (°C) | Representative Indicator Plant Species |
|---|---|---|---|
| Zone 3 | -40°F to -30°F | -40.0°C to -34.4°C | Siberian Iris, Silver Maple, Tatarian Dogwood |
| Zone 4 | -30°F to -20°F | -34.4°C to -28.9°C | Daylily, Hostas, Sugar Maple, Honeycrisp Apple |
| Zone 5 | -20°F to -10°F | -28.9°C to -23.3°C | Eastern Redbud, Forsythia, English Lavender |
| Zone 6 | -10°F to 0°F | -23.3°C to -17.8°C | Japanese Maple, Boxwood, Peach, Boston Ivy |
| Zone 7 | 0°F to 10°F | -17.8°C to -12.2°C | Crape Myrtle, Southern Magnolia, Fig, Azalea |
| Zone 8 | 10°F to 20°F | -12.2°C to -6.7°C | Rosemary, Camellia, Loquat, Gardenia |
| Zone 9 | 20°F to 30°F | -6.7°C to -1.1°C | Orange, Lemon, Olive, Bird of Paradise |
| Zone 10 | 30°F to 40°F | -1.1°C to +4.4°C | Bougainvillea, Royal Palm, Mango, Papaya |