When to Plant in Cambridge, MA

In Cambridge, the median last spring frost date is April 22, while the median first fall frost occurs on October 19, providing approximately 180 frost-free days for gardening. This timeframe provides ample opportunity for a variety of plantings and yields, fostering a vibrant local gardening culture. Understanding these frost dates is crucial for timing your sowing and planting activities effectively, ensuring that crops can grow to maturity without the threat of frost damage.

The climate in Cambridge falls under the humid continental (cold winters) category, which significantly influences the types of crops that thrive in this region. Vegetables such as kale, radishes, and carrots are particularly well-suited to the colder winters and can be planted early in the spring, leveraging the cool temperatures for optimal growth. However, heat-sensitive crops like tomatoes and peppers often struggle, as they require warmer temperatures to flourish. The pronounced seasonal changes influence soil temperatures and moisture levels, making timing essential for successful gardening.

What to plant now in Cambridge

In late April, after the last frost on April 22, consider planting cool-season crops such as lettuce, peas, and spinach. These crops thrive in the remaining cool temperatures of spring and can be harvested before the heat sets in.
During the summer months, from June to early July, plant summer crops like tomatoes and peppers. These plants should be in the ground by mid-May to ensure enough growing time before the first fall frost on October 19.
As fall approaches in late August through September, you can still plant late-season crops, including Brussels sprouts and fall greens like collards or mustard. Plant these by mid-September to ensure they mature before the cold intensifies.
In early November, as the first frosts are approaching, focus on cleaning up the garden and preparing it for winter. Mulch any remaining perennials and consider planting garlic which can be sown before the ground freezes.

In Cambridge (180 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.

Month by month in Cambridge

Month	What to do
January	In January, prioritize indoor gardening by starting seeds for early spring crops. This includes tomatoes and peppers, which require a long growing season. Utilize grow lights for optimal results during the short daylight hours.
February	February is the time to continue starting seeds indoors. Consider cabbage, broccoli, and other cruciferous vegetables. As the days gradually lengthen, prepare your garden tools and plan for the upcoming planting season.
March	March is ideal for preparing garden beds outdoors. Clean up last year’s debris and amend soil with organic matter. Start hardening off seedlings during warmer days towards the end of the month, preparing them for outdoor transplanting.
April	April marks the arrival of spring. As you approach April 22, the last frost date, begin direct sowing carrots, radishes, and greens. Monitor nighttime temperatures to safeguard any tender seedlings from unexpected frosts.
May	In May, after the threat of frost has passed, plant warm-season crops like tomatoes and peppers. By mid-month, the soil will have warmed sufficiently, promoting vigorous growth for these heat-loving plants.
June	June is prime for maintaining established plants. Regularly water crops and add mulch to retain soil moisture. Harvest early crops and prepare the ground for succession planting of mid-summer crops.
July	In July, continue to care for your garden. This month is focused on watering, weeding, and monitoring for pests. Additionally, prepare for fall by planning and planting fall crops like winter squash.
August	August marks the late summer transition. Start planting fall crops, such as Brussels sprouts and hardy greens. Monitor the weather for the first cool snaps signaling time for fall preparations.
September	In September, be vigilant as the first frost date of October 19 approaches. Harvest mature crops and continue sowing fast-maturing varieties for a late fall harvest before the chill sets in.
October	October is the time to finalize your fall preparations. As the first frost on October 19 arrives, begin to clean up the garden, protect delicate perennials, and apply mulch to insulate soil for winter.
November	November is primarily about garden cleanup. Remove dead plant material to prevent disease and pests. Consider planting garlic as a winter crop and planning for next year's garden layout.
December	In December, focus on indoor gardening such as forcing bulbs or caring for houseplants. Reflect on the past growing season while planning seeds for the following year, aligning with frost dates.

Frost dates for Cambridge ZIP codes

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
02139	April 22	October 19	6b

FAQ

When is the last frost in Cambridge?

The last frost date in Cambridge is April 22. This date is essential for planning your spring plantings.

What vegetables grow best in Cambridge?

Vegetables such as kale, radishes, and carrots excel in Cambridge's humid continental climate, benefiting from cooler temperatures in spring and fall.

When should I plant tomatoes in Cambridge?

Tomatoes should ideally be planted after the last frost on April 22, with mid-May being the optimal time to ensure a good harvest before the fall frost.

Can I garden year-round in Cambridge?

Gardening year-round in Cambridge can be challenging due to cold winters, but winter crops like garlic can be planted to extend the season.

How does Plan My Garden help Cambridge gardeners?

Plan My Garden offers tailored advice on planting schedules, frost dates, and crop selection suited to Cambridge’s unique climate, helping gardeners maximize their yields.