When Is the Last Frost in Maryland?
The average last spring frost in Maryland falls between March 27 and April 19 for most ZIP codes, with a statewide median of April 5. At the average date a later frost is still a coin flip, so tender plants wait for the safer 90% date.
| City | Last frost | 90% safe after | First frost | Growing season |
|---|---|---|---|---|
| Baltimore | Mar 24 | Apr 4 | Nov 21 | 244 days |
| Frederick | Apr 2 | Apr 15 | Nov 6 | 218 days |
| Gaithersburg | Apr 1 | Apr 15 | Nov 6 | 219 days |
| Rockville | Apr 1 | Apr 15 | Nov 6 | 219 days |
| Bowie | Apr 22 | May 9 | Oct 22 | 183 days |
| Hagerstown | Apr 11 | Apr 27 | Oct 28 | 199 days |
| Annapolis | Mar 23 | Apr 6 | Nov 20 | 241 days |
| College Park | Apr 10 | May 1 | Nov 1 | 202 days |
| Salisbury | Apr 3 | Apr 25 | Nov 7 | 217 days |
| Laurel | Apr 5 | Apr 19 | Nov 9 | 218 days |
| Westminster | Apr 19 | May 8 | Oct 25 | 188 days |
| Cumberland | Apr 15 | May 5 | Oct 24 | 190 days |
| Aberdeen | Apr 10 | Apr 30 | Oct 30 | 201 days |
| Easton | Apr 1 | Apr 15 | Nov 7 | 220 days |
| Elkton | Apr 7 | Apr 21 | Nov 2 | 208 days |
| La Plata | Apr 17 | May 2 | Oct 27 | 195 days |
| Ocean City | Apr 7 | Apr 23 | Nov 2 | 209 days |
| Chesapeake Beach | Apr 9 | Apr 24 | Oct 29 | 203 days |
Last and first frost: 50% (median) dates of the last spring and first fall 32 °F night. 90% safe after: only a 10% chance of a later spring frost. First frost dates in January fall in the following winter. Each city uses the NOAA station nearest the ZIP code closest to its center.
Across all 43 Maryland weather stations with frost records, median last frost dates run from March 22 at Solomons, MD to May 9 at Sines Deep Creek, MD. Elevation, valleys that collect cold air and distance from large water bodies explain most of the spread, so a garden a few miles from a listed city can differ by a week or more. The ZIP code lookup above uses the same NOAA data as the frost date calculator for every US ZIP code.
When Is the First Frost in Maryland?
The average first fall frost in Maryland arrives between October 24 and November 15 for most ZIP codes, with a median of November 5. Tomatoes, peppers, basil and squash are damaged at 32 °F, so harvest or cover them before then.
Fall frost can come early: Baltimore has a 10% chance of frost before November 7, Frederick has a 10% chance of frost before October 23 and Gaithersburg has a 10% chance of frost before October 24. Hardy crops such as kale, spinach and cabbage tolerate light frosts and keep producing after the first frost date.
When to Plant Tomatoes in Maryland?
Transplant tomatoes in Maryland 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Mar 31 – Apr 7 in Baltimore, Apr 9 – Apr 16 in Frederick and Apr 8 – Apr 15 in Gaithersburg. Start seeds indoors 6 to 8 weeks before the last frost.
| City | Start seeds indoors | Transplant outdoors | Lowest-risk transplant |
|---|---|---|---|
| Baltimore | Jan 27 – Feb 10 | Mar 31 – Apr 7 | after Apr 4 |
| Frederick | Feb 5 – Feb 19 | Apr 9 – Apr 16 | after Apr 15 |
| Gaithersburg | Feb 4 – Feb 18 | Apr 8 – Apr 15 | after Apr 15 |
| Rockville | Feb 4 – Feb 18 | Apr 8 – Apr 15 | after Apr 15 |
| Bowie | Feb 25 – Mar 11 | Apr 29 – May 6 | after May 9 |
| Hagerstown | Feb 14 – Feb 28 | Apr 18 – Apr 25 | after Apr 27 |
| Annapolis | Jan 26 – Feb 9 | Mar 30 – Apr 6 | after Apr 6 |
| College Park | Feb 13 – Feb 27 | Apr 17 – Apr 24 | after May 1 |
| Salisbury | Feb 6 – Feb 20 | Apr 10 – Apr 17 | after Apr 25 |
| Laurel | Feb 8 – Feb 22 | Apr 12 – Apr 19 | after Apr 19 |
| Westminster | Feb 22 – Mar 8 | Apr 26 – May 3 | after May 8 |
| Cumberland | Feb 18 – Mar 4 | Apr 22 – Apr 29 | after May 5 |
| Aberdeen | Feb 13 – Feb 27 | Apr 17 – Apr 24 | after Apr 30 |
| Easton | Feb 4 – Feb 18 | Apr 8 – Apr 15 | after Apr 15 |
| Elkton | Feb 10 – Feb 24 | Apr 14 – Apr 21 | after Apr 21 |
| La Plata | Feb 20 – Mar 6 | Apr 24 – May 1 | after May 2 |
| Ocean City | Feb 10 – Feb 24 | Apr 14 – Apr 21 | after Apr 23 |
| Chesapeake Beach | Feb 12 – Feb 26 | Apr 16 – Apr 23 | after Apr 24 |
Indoors: 6–8 weeks before the average last frost. Outdoors: 1–2 weeks after it. Lowest-risk: after the date with only a 10% chance of a later frost. Rules of thumb; check the 10-day forecast and wait for soil near 60 °F.
Tomatoes stall below about 50 °F at night and are killed by frost, so a week or two of waiting after the average date costs little. The tomato plant care guide covers light, watering and feeding once plants are in the ground.
What Can You Plant in Baltimore and When?
Baltimore's average last frost of March 24 anchors its spring planting calendar: peas and spinach go in from February 10, broccoli and lettuce transplants from February 24, and tomatoes, peppers and squash after March 31.
| Crop | Start seeds indoors | Plant outdoors | Frost tolerance |
|---|---|---|---|
| Peas | — | Feb 10 – Feb 24direct sow, 4–6 weeks before last frost | hardy |
| Spinach | — | Feb 10 – Mar 3direct sow, 3–6 weeks before last frost | hardy |
| Radishes | — | Feb 17 – Mar 3direct sow, 3–5 weeks before last frost | hardy |
| Onions (sets) | — | Feb 24 – Mar 10plant, 2–4 weeks before last frost | hardy |
| Potatoes | — | Feb 24 – Mar 10plant, 2–4 weeks before last frost | half-hardy |
| Broccoli & cabbage | Jan 27 – Feb 10 | Feb 24 – Mar 10transplant, 2–4 weeks before last frost | hardy |
| Lettuce | Feb 10 – Feb 24 | Feb 24 – Mar 10transplant, 2–4 weeks before last frost | hardy |
| Beets | — | Feb 24 – Mar 10direct sow, 2–4 weeks before last frost | half-hardy |
| Carrots | — | Mar 3 – Mar 10direct sow, 2–3 weeks before last frost | half-hardy |
| Tomatoes | Jan 27 – Feb 10 | Mar 31 – Apr 7transplant, 1–2 weeks after last frost | tender |
| Basil | Jan 27 – Feb 10 | Mar 31 – Apr 14transplant, 1–3 weeks after last frost | tender |
| Peppers | Jan 13 – Jan 27 | Apr 7 – Apr 14transplant, 2–3 weeks after last frost | tender |
| Eggplant | Jan 13 – Jan 27 | Apr 7 – Apr 14transplant, 2–3 weeks after last frost | tender |
| Green beans | — | Mar 31 – Apr 14direct sow, 1–3 weeks after last frost | tender |
| Sweet corn | — | Mar 31 – Apr 14direct sow, 1–3 weeks after last frost | tender |
| Cucumbers | Feb 24 – Mar 3 | Mar 31 – Apr 14transplant, 1–3 weeks after last frost | tender |
| Squash & zucchini | Feb 24 – Mar 3 | Mar 31 – Apr 14transplant, 1–3 weeks after last frost | tender |
| Watermelon | Feb 24 – Mar 3 | Apr 7 – Apr 14transplant, 2–3 weeks after last frost | tender |
Dates for Baltimore (last frost Mar 24, NOAA station Md Sci Ctr Baltimore, MD, under 1 mile from ZIP 21202). General rules of thumb; wait for soil near 50 °F for most seeds and 60 °F for beans, corn and squash.
How Long Is the Growing Season in Maryland?
The frost-free growing season in Maryland lasts about 188 to 234 days for most ZIP codes, with a median of 217 days. Among the listed cities, Bowie has the shortest season at 183 days and Baltimore the longest at 244.
Season length decides which varieties ripen: compare it with the “days to maturity” on seed packets, counted from transplanting for tomatoes and peppers. NOAA stations in Maryland range from 155 days at Sines Deep Creek, MD to 248 days at Solomons, MD. Planning beds before the season starts helps in short seasons — a plant spacing calculator for vegetable beds shows how many transplants fit.
What Hardiness Zones Are in Maryland?
Maryland spans USDA hardiness zones 6a to 8a, with zone 7b the most common. Zones describe winter cold and decide which perennials survive, while frost dates set when to plant annual vegetables and flowers.
The Maryland planting zone map with the zone of each city shows how the zones are spread across the state and which plants are hardy in all of them.
Frequently Asked Questions
- When is the last frost in Maryland?
- The average last spring frost in Maryland falls between March 27 and April 19 for most ZIP codes, with a statewide median of April 5. Among major cities it ranges from March 23 in Annapolis to April 22 in Bowie.
- When is the last frost in Baltimore, Maryland?
- Baltimore's average last spring frost is March 24, and by April 4 the chance of a later frost drops to 10%. Its first fall frost averages November 21, giving a 244-day growing season (NOAA station Md Sci Ctr Baltimore, MD).
- When should you plant tomatoes in Maryland?
- Transplant tomatoes in Maryland 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Mar 31 – Apr 7 in Baltimore, Apr 9 – Apr 16 in Frederick and Apr 8 – Apr 15 in Gaithersburg. Start seeds indoors 6 to 8 weeks before the last frost.
- When is the first frost in Maryland?
- The average first fall frost in Maryland arrives between October 24 and November 15 for most ZIP codes, with a median of November 5. Harvest tender crops such as tomatoes, peppers and basil before then or cover them on cold nights.
- How long is the growing season in Maryland?
- The frost-free growing season in Maryland lasts about 188 to 234 days for most ZIP codes, with a median of 217 days, from 183 days in Bowie to 244 days in Baltimore.
Frost data: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (32 °F freeze dates by probability). ZIP code and city locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. Planting windows are general rules of thumb. PlantoScan is not affiliated with or endorsed by these agencies.