Massachusetts Frost Dates & Growing Season Guide
Massachusetts (MA) spans USDA hardiness zones 6a, 6b, 7a, with growing seasons ranging from 165 days in Worcester to 214 days in Cape Cod. The average growing season across the state is approximately 190 days.
Massachusetts 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 Massachusetts
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 |
|---|---|---|---|
| Boston | February 19 | April 22 | August 21 |
| Worcester | March 10 | May 12 | August 1 |
| Springfield | March 4 | May 6 | August 6 |
| Cape Cod | February 16 | April 19 | August 27 |
Gardening in Massachusetts
Massachusetts gardening benefits from the moderating influence of the Atlantic Ocean along the coast while inland areas experience more temperature extremes. Boston's urban heat island and coastal proximity push it toward zone 6b with over 200 frost-free days, while Worcester at higher elevation sits in zone 6a with a shorter season. The state's rocky, acidic soils suit blueberries and potatoes well but need lime for most vegetable crops. Cool-season crops perform beautifully in the state's spring and fall, and heat-loving crops like tomatoes and peppers do best with south-facing exposure and season-extending techniques. Cape Cod's sandy soils warm up fast in spring, giving it one of the earliest planting windows in the state.
Understanding Massachusetts's Hardiness Zones
Massachusetts includes USDA hardiness zones 6a, 6b, 7a. 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 Massachusetts 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.