USDA hardiness zones, and what they leave out
A hardiness zone tells you how cold a typical winter gets. It’s the first filter for choosing plants — not the last. Pick a zone to see what it means and which catalog plants are rated for it.
| Zone | Average extreme winter low | Catalog plants | Typical places |
|---|---|---|---|
| Zone 3 | -40 to -30 °F (-40 to -34 °C) | 55 | Among the coldest gardened places in the lower 48: high northern mountains and the far northern plains. Short seasons and deep cold limit woody plants to the toughest species. |
| Zone 4 | -30 to -20 °F (-34 to -29 °C) | 104 | Northern New England, the Adirondacks, the upper Midwest and high-elevation valleys of the West. Plant hardiness, not summer heat, is the main filter. |
| Zone 5 | -20 to -10 °F (-29 to -23 °C) | 139 | Much of interior New England and upstate New York, the central Midwest and the higher plateaus of the West. A broad palette of temperate trees and shrubs is reliable. |
| Zone 6 | -10 to 0 °F (-23 to -18 °C) | 158 | Southern New England, much of Pennsylvania and the mid-Atlantic interior, and mountain areas of the upper South. Many plants marketed as “zone 7” are marginal here. |
| Zone 7 | 0 to 10 °F (-18 to -12 °C) | 182 | Coastal and urban parts of the Northeast, the Upper South and Piedmont, and mid-elevation parts of the Southwest. Both northern and southern palettes overlap — heat and humidity start to matter. |
| Zone 8 | 10 to 20 °F (-12 to -7 °C) | 196 | The Coastal Plain of the Carolinas and Georgia, north Florida, much of the Gulf South and warmer parts of the Southwest. Winters are short; summer heat and drought shape plant choice. |
| Zone 9 | 20 to 30 °F (-7 to -1 °C) | 167 | Central Florida, the Gulf Coast and the low deserts of Arizona. Frost is occasional; heat tolerance and water use decide most plant choices. |
| Zone 10 | 30 to 40 °F (-1 to 4 °C) | 84 | South-central Florida, the warmest low deserts and coastal southern California. Many tropical and subtropical plants are possible; cold snaps are rare but damaging. |
| Zone 11 | 40 to 50 °F (4 to 10 °C) | 29 | Frost-free places such as the Florida Keys. Few temperate plants succeed; the palette is tropical. |
Zones come from the USDA Plant Hardiness Zone Map. Use the zone & region lookup for a quick state-level starting point.
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