Massachusetts · zones 5a–7a
When to plant green beans in Massachusetts.
Sow between Apr 22 to Jun 12 in a typical year, keyed to Massachusetts's median last frost around Apr 22. A second, fall sowing fits Jul 6 to Aug 8. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Green Beans dates for a typical Massachusetts season.
Direct sow
Apr 22 to Jun 12
Keyed to the ~Apr 22 last frost. Sow 1" deep, 3" apart.
Fall round
Jul 6 to Aug 8
Counted back from the ~Oct 20 first frost.
Harvest
~55 days later
~0.75 lb per plant over ~3 weeks.
Massachusetts spans more than one climate: Zone 6 is the most common zone, but the state runs 5a to 7a. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
Massachusetts growing notes
A Massachusetts bean crop lives or dies on how fast it dries out after rain.
Soil warmth beats the calendar for germination
Bean seed rots more often than it just sits slow when it goes into ground still under 60 degrees at a 2-inch reading, and a cool coastal spring or a late Berkshire frost can leave Massachusetts soil lagging well behind the air temperature for weeks at a stretch. Testing with an actual thermometer beats sowing off a fixed date here, since the gap between air warmth and soil warmth is exactly what catches gardeners out.
Succession sowing every couple of weeks keeps a CSA share stocked with beans through the summer instead of delivering one overwhelming flush; Massachusetts' roughly six-month frost-free window gives room to fit in a dozen or more rounds between the last spring frost and the first one in fall.
Rust and powdery mildew love a humid August
Coastal humidity and the fog that regularly rolls in along the South Shore and Cape create the damp foliage both rust and powdery mildew need to establish; rust shows as small orange-brown pustules on the leaf underside, while powdery mildew leaves a gray-white dusting across the top. Both spread fastest on leaves that stay wet overnight, so watering the soil directly in the morning rather than the foliage in the evening is the cheapest available defense.
Give the row enough elbow room that a hand slides between plants without brushing leaves on either side, and pick beans once the row has dried off rather than while dew still clings to the leaves, so a gardener's own hands aren't the thing carrying spores down the row faster than the weather alone would spread them.
Mexican bean beetle looks helpful until it isn't
Mexican bean beetle is coppery and spotted enough to pass for a beneficial ladybug at a glance, right up until its yellow, spiny larvae show up feeding from underneath the leaves and skeletonizing them from below. A weekly walk down the row flipping leaves catches both the tidy yellow egg clusters and the larvae before the damage climbs.
Hand-crushing those egg clusters as soon as you spot them is the single most effective habit against this pest, since one cluster left alone hatches into dozens of feeding larvae within roughly the same span it takes an aphid colony to mature.
In Massachusetts: watch for
The pests that find green beans here.
A middle-length season, about 181 frost-free days, means bush bean overlaps mexican bean beetle for a stretch each summer. Check plants every week or two and treat early.
Coppery ladybug-like beetles; leaves skeletonized to lace.
Organic fix: Handpick adults and yellow egg clusters; neem.
Orange or white spots on leaves late in the season.
Organic fix: Water at the base, space plants, spray neem.
Anthracnose
Sunken dark-red cankers on the pods, and leaf veins turning brick-red to black underneath.
Organic fix: Start with certified seed, water at the base, and stay out of the patch while the leaves are wet.
Your season math: Massachusetts gives green beans about 181 frost-free days, and it needs roughly 55 days to a first harvest. That fits about 13 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting green beans in Massachusetts: questions
When should I plant green beans in Massachusetts?+
In a typical Massachusetts year, sow green beans between Apr 22 to Jun 12, keyed to the state's median last frost around Apr 22. There's also a fall window: Jul 6 to Aug 8. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Massachusetts?+
Massachusetts spans zones 5a–7a, mostly zone 6. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many green beans plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.