Maryland Frost Dates & Growing Season Guide
Maryland (MD) spans USDA hardiness zones 6a, 6b, 7a, 7b, with growing seasons ranging from 168 days in Cumberland to 215 days in Baltimore. The average growing season across the state is approximately 194 days.
Maryland City Frost Dates
The table below shows the average last spring frost date, first fall frost date, growing season length, and USDA hardiness zone for each city. Click a city name for detailed planting calendars and zone information.
Planting Windows for Maryland
Based on average frost dates, here are the recommended planting windows for each city. The indoor seed start date is approximately seven weeks before the last spring frost. Transplanting should occur about two weeks after the last frost. The last direct sow date for fall crops is ten weeks before the first fall frost.
| City | Start Seeds Indoors | Transplant After | Last Direct Sow |
|---|---|---|---|
| Baltimore | February 14 | April 17 | August 26 |
| Annapolis | February 17 | April 20 | August 23 |
| Frederick | February 29 | May 2 | August 9 |
| Cumberland | March 7 | May 9 | August 1 |
Gardening in Maryland
Maryland packs surprising climate diversity into a small state. The Eastern Shore and Chesapeake Bay region enjoy mild, maritime-influenced weather with longer growing seasons, while the Appalachian western counties around Cumberland and Frederick have cooler conditions. Most of the state sits in zones 6b to 7b, supporting a full range of temperate vegetables. Maryland's proximity to the coast moderates temperature extremes in much of the state. Tomatoes, peppers, squash, and cucumbers are summertime staples. The state's variable soils range from sandy coastal plain to heavy Piedmont clay, so soil testing and appropriate amendment make a significant difference in garden performance.
Understanding Maryland's Hardiness Zones
Maryland includes USDA hardiness zones 6a, 6b, 7a, 7b. These zones indicate the average annual extreme minimum winter temperature for each area, which determines which perennial plants, trees, and shrubs can survive winter without protection. When purchasing trees, shrubs, or perennial flowers, always check that the plant is rated for your hardiness zone or a lower (colder) zone number.
Tips for Using Maryland Frost Dates
These frost dates represent long-term averages and should be treated as guidelines rather than guarantees. In any given year, the actual last spring frost or first fall frost may arrive one to three weeks earlier or later than the average. Factors that affect your specific location include elevation above the city center, proximity to water, slope direction, and whether you are in an urban or rural area. South-facing slopes and areas near large pavement or building masses tend to be warmer than surrounding open land. Low-lying valleys and exposed hilltops are often colder than mid-slope positions.
To protect against late spring frosts, keep row cover fabric, old bed sheets, or frost blankets on hand. Monitor your local weather forecast daily as the average frost date approaches. When frost is predicted after you have transplanted, covering plants in the late afternoon traps ground heat and can protect against temperatures down to about 28 degrees Fahrenheit. For fall season extension, the same covers protect mature plants from early frosts, often buying several additional weeks of harvest.