The 1990 USDA Plant Hardiness Zone Map for Maryland was the official USDA zone reference for over two decades. It was based on average annual extreme minimum winter temperature data collected from 1974 to 1986. Use the table below to compare 1990 zones to the revised 2012 zones and the current 2023 zones.
| Location | 1990 Hardiness Zone | 2012 Zone | 2023 Zone |
|---|---|---|---|
| Aberdeen | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Adelphi | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Annapolis | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Arbutus | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Arnold | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Aspen Hill | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Ballenger Creek | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Baltimore | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Beltsville | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Bethesda | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Bowie | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Brooklyn Park | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Calverton | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Camp Springs | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Carney | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Catonsville | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Chillum | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Clinton | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Cloverly | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Cockeysville | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Colesville | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| College Park | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Crofton | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Cumberland | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7a — 0°F to 5°F |
| Damascus | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Dundalk | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Easton | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Edgewood | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Eldersburg | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7a — 0°F to 5°F |
| Elkridge | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Elkton | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Ellicott City | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Essex | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Fairland | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Ferndale | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Fort Washington | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Frederick | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Gaithersburg | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Germantown | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Glassmanor | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Glen Burnie | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Glenmont | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Greenbelt | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Hagerstown | 6b — -5°F to 0°F | 6b — -5°F to 0°F | 7a — 0°F to 5°F |
| Hillcrest Heights | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Hyattsville | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Joppatowne | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Lake Shore | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Landover | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Langley Park | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Laurel | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Lexington Park | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Linganore | 6a — -10°F to -5°F | 6b — -5°F to 0°F | 7a — 0°F to 5°F |
| Lochearn | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Maryland City | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Middle River | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Milford Mill | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Montgomery Village | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| North Bethesda | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| North Laurel | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Odenton | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Olney | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Owings Mills | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Oxon Hill | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Parkville | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Perry Hall | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Pikesville | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Potomac | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Randallstown | 7a — 0°F to 5°F | 6b — -5°F to 0°F | 7a — 0°F to 5°F |
| Redland | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Reisterstown | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7a — 0°F to 5°F |
| Rockville | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Rosedale | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Salisbury | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 7b — 5°F to 10°F |
| Severn | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Severna Park | 7a — 0°F to 5°F | 7b — 5°F to 10°F | 8a — 10°F to 15°F |
| Silver Spring | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| South Laurel | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Suitland | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Takoma Park | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Towson | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Waldorf | 7a — 0°F to 5°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| Westminster | 7a — 0°F to 5°F | 6b — -5°F to 0°F | 7a — 0°F to 5°F |
| Wheaton | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
| White Oak | 6b — -5°F to 0°F | 7a — 0°F to 5°F | 7b — 5°F to 10°F |
The 1990 USDA Plant Hardiness Zone Map was produced by the U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) in collaboration with the American Horticultural Society. It served as the official US planting zone reference from 1990 until the 2012 revision.
Official source: USDA Plant Hardiness Zone Map — planthardiness.ars.usda.gov
This interactive map presentation is provided by PlantMaps. The underlying hardiness zone boundary data is sourced from the USDA Agricultural Research Service. Zone assignments for individual cities and towns are derived from PlantMaps climate data.