What Planting Zones Are in Maryland?
Maryland spans USDA hardiness zones 6a to 8a, where the average coldest winter night ranges from −10 °F to 15 °F (−23.3 °C to −9.4 °C). Zone 7b covers the most ZIP codes, 61%, and zones 7a to 8a together cover 97% of the state.
Bars show each zone's share of the 598 Maryland ZIP codes in the official 2023 USDA ZIP code table; select a zone for its temperatures and hardy plants.
What Hardiness Zone Are Maryland Cities In?
Baltimore is in zone 8a, Frederick is in zone 7b, Gaithersburg is in zone 7b and Rockville is in zone 7b. The table lists the zone, winter low and average frost dates for 18 Maryland cities, using the ZIP code nearest each city center.
| City | ZIP | Zone | Winter low | Last frost | First frost |
|---|---|---|---|---|---|
| Baltimore | 21202 | 8a | 10 °F to 15 °F | Mar 24 | Nov 21 |
| Frederick | 21705 | 7b | 5 °F to 10 °F | Apr 2 | Nov 6 |
| Gaithersburg | 20877 | 7b | 5 °F to 10 °F | Apr 1 | Nov 6 |
| Rockville | 20850 | 7b | 5 °F to 10 °F | Apr 1 | Nov 6 |
| Bowie | 20715 | 7a | 0 °F to 5 °F | Apr 22 | Oct 22 |
| Hagerstown | 21740 | 7a | 0 °F to 5 °F | Apr 11 | Oct 28 |
| Annapolis | 21402 | 8a | 10 °F to 15 °F | Mar 23 | Nov 20 |
| College Park | 20742 | 7b | 5 °F to 10 °F | Apr 10 | Nov 1 |
| Salisbury | 21826 | 7b | 5 °F to 10 °F | Apr 3 | Nov 7 |
| Laurel | 20707 | 7b | 5 °F to 10 °F | Apr 5 | Nov 9 |
| Westminster | 21157 | 7a | 0 °F to 5 °F | Apr 19 | Oct 25 |
| Cumberland | 21502 | 7a | 0 °F to 5 °F | Apr 15 | Oct 24 |
| Aberdeen | 21001 | 7b | 5 °F to 10 °F | Apr 10 | Oct 30 |
| Easton | 21601 | 8a | 10 °F to 15 °F | Apr 1 | Nov 7 |
| Elkton | 21921 | 7b | 5 °F to 10 °F | Apr 7 | Nov 2 |
| La Plata | 20646 | 7b | 5 °F to 10 °F | Apr 17 | Oct 27 |
| Ocean City | 21842 | 8a | 10 °F to 15 °F | Apr 7 | Nov 2 |
| Chesapeake Beach | 20714 | 8a | 10 °F to 15 °F | Apr 9 | Oct 29 |
Zone: 2023 USDA ZIP code table for the ZIP code nearest each city's Census center point. Frost dates: 50% (median) dates from the nearest NOAA station, 1991–2020 normals. Cities: the largest Maryland places by 2024 Census population estimates, spread across the state, plus the largest place in each common zone. Large cities can span two half zones.
Which Parts of Maryland Are in Each Zone?
Zone 6a, the coldest Maryland zone, covers 2% of ZIP codes around Mountain Lake Park and Oakland. Zone 8a, the warmest, covers 20% around Baltimore, Annapolis and Easton. The table lists the largest places in every zone.
| Zone | Avg. coldest night | Share of ZIPs | Largest places in this zone |
|---|---|---|---|
| Zone 6a | −10 °F to −5 °F | 2% (9) | Mountain Lake Park, Oakland |
| Zone 6b | −5 °F to 0 °F | 1% (7) | Frostburg |
| Zone 7a | 0 °F to 5 °F | 16% (98) | Bowie, Hagerstown, Westminster, Cumberland |
| Zone 7b | 5 °F to 10 °F | 61% (366) | Frederick, Gaithersburg, Rockville, College Park |
| Zone 8a | 10 °F to 15 °F | 20% (118) | Baltimore, Annapolis, Easton, Cambridge |
Places: incorporated places with 1,000+ residents, assigned the zone of the ZIP code nearest their Census center point.
What Do the Hardiness Zones Mean for Maryland Gardeners?
A Maryland gardener in zone 8a sees winter lows about 20 °F milder than one in zone 6a, so a shrub or perennial that thrives in one part of the state can die in another. Choose plants rated to your own ZIP code's zone or colder.
Hardiness zones follow latitude, elevation and large bodies of water rather than state lines. Higher ground and inland valleys that trap cold air usually sit in colder half zones, while cities, coasts and large lakes moderate winter lows. Within Maryland, a plant labelled “zones 7–8” survives winter in at least 97% of ZIP codes, but plants at the edge of their range benefit from mulch and a sheltered spot. Enter a ZIP code in the USDA hardiness zone finder by ZIP code to check your exact half zone before buying perennials.
A zone describes winter cold only. Summer heat, humidity, rainfall and soil decide whether a cold-hardy plant thrives, and planting dates for vegetables follow frost dates, not zones: two Maryland towns in the same zone can have last frosts weeks apart.
What Plants Grow Well Across Maryland?
230 plants in PlantoScan's catalogue are hardy in every zone from 7a to 8a, the zones that cover 97% of Maryland ZIP codes. Popular examples include hydrangea, peony and daisy.
Hydrangea
Hydrangea macrophylla
Zone 5 – 9
AI generated
Peony
Paeonia lactiflora
Zone 3 – 8
AI generated
- DaisyBellis perennisPlantoScan
Daisy
Bellis perennis
Zone 4a – 8b
Chrysanthemum
Chrysanthemum morifolium
Zone 5a – 9b
PlantoscanAI generated
Poppy
Papaver somniferum
Zone 3a – 9b
AI generated
Carnation
Dianthus caryophyllus
Zone 5a – 9b
AI generated
Daffodil
Narcissus poeticus
Zone 3 – 8
AI generated
Azalea
Azalea indica
Zone 6a – 9b
AI generated
Arugula
Eruca sativa
Zone 5a – 10b
AI generated
Hardiness ranges come from PlantoScan's plant database; gardeners in Maryland's colder or warmer edge zones should check each plant's full range.
When Is the Last Frost in Maryland?
Across most Maryland ZIP codes, the average last spring frost falls between March 27 and April 19, from March 23 in Annapolis to April 22 in Bowie. Tender vegetables such as tomatoes go out 1 to 2 weeks after the local date.
The last and first frost dates for Maryland cities include the safer 90% planting date, the fall frost date, growing season length and a tomato planting table for each city.
Frequently Asked Questions
- What planting zone is Maryland?
- Maryland spans USDA hardiness zones 6a to 8a on the 2023 USDA Plant Hardiness Zone Map. Zone 7b is the most common, covering 61% of the state's 598 ZIP codes, and zones 7a to 8a together cover 97%.
- What hardiness zone is Baltimore, Maryland?
- Baltimore is in USDA hardiness zone 8a (ZIP 21202), where the average coldest winter night reaches 10 °F to 15 °F. Its average last spring frost is March 24 and its first fall frost November 21.
- What hardiness zone is Frederick, Maryland?
- Frederick is in USDA hardiness zone 7b (ZIP 21705), where the average coldest winter night reaches 5 °F to 10 °F. Its average last spring frost is April 2 and its first fall frost November 6.
- What hardiness zone is Gaithersburg, Maryland?
- Gaithersburg is in USDA hardiness zone 7b (ZIP 20877), where the average coldest winter night reaches 5 °F to 10 °F. Its average last spring frost is April 1 and its first fall frost November 6.
- What is the coldest hardiness zone in Maryland?
- Zone 6a (−10 °F to −5 °F) is the coldest zone in Maryland, found in 9 ZIP codes around Mountain Lake Park and Oakland. The warmest is zone 8a (10 °F to 15 °F), around Baltimore and Annapolis.
Zones: 2023 USDA Plant Hardiness Zone Map ZIP code table, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University, used without changes. Frost dates: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals. City locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. PlantoScan is not affiliated with or endorsed by these agencies.