Massachusetts · zones 5a–7a
When to plant broccoli in Massachusetts.
Sow or transplant between Mar 1 to Mar 29 in a typical year, keyed to Massachusetts's median last frost around Apr 22. A second, fall sowing fits Jul 6 to Aug 15. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Broccoli dates for a typical Massachusetts season.
1 · Start indoors
Jan 18 to Feb 15
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Mar 1 to Mar 29
Keyed to the ~Apr 22 last frost. Sow 0.5" deep, 18" apart.
Fall round
Jul 6 to Aug 15
Counted back from the ~Oct 20 first frost.
Harvest
~60 days later
~1.2 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
Fall is when Massachusetts broccoli actually earns its bed space.
Maritime air buys a longer finish than the inland valley gets
Coastal Massachusetts, the South Shore, Cape Cod, and the Islands, runs measurably cooler through late summer than the Connecticut River valley on the state's western side, where inland heat builds with no ocean nearby to pull it back down. That gap matters for broccoli, since a head sizing up during a hot stretch often rices, breaking into loose, yellow-tinged beads instead of staying a tight blue-green dome, and coastal growers can push a fall crop later into cool weather before that risk sets in.
Inland gardeners in the Pioneer Valley or the Berkshires without that ocean buffer do better timing the transplant so the head finishes as nights start cooling rather than during a July heat spike; a fall-set crop growing into shortening, cooling days tightens up instead of racing to bolt the way an ill-timed spring planting can.
Acid till and the clubroot test
Massachusetts till, dropped by retreating glaciers, runs acidic across most of the state, and clubroot, a soil fungus that swells and distorts brassica roots, favors exactly that combination of damp ground and low pH. There is no cure once a plant is infected, so the real test happens with a shovel, not a soil kit: any broccoli that wilts on a sunny morning despite moist soil is worth pulling and slicing at the root, since clean white root hairs are normal and swollen, club-shaped galls are not.
Cape Cod and the Islands sit on sandier, faster-draining ground that sheds the standing moisture clubroot needs, one of the few gardening advantages of beach sand, while inland growers on heavier till don't get that break and should raise the bed 4 to 6 inches to keep water moving through rather than pooling around the crown. Either way, lime worked in the fall before planting, based on an actual soil test, is the standing defense.
Scouting a head crop you can't spray late
Ragged notches along a leaf edge, rather than the fine pinholes flea beetles leave, point to cabbage worms or loopers hiding on the underside where their green blends into the leaf; running a hand along the underside of ten leaves once a week, feeling for the caterpillars rather than just scanning for holes, catches them before the damage reaches the forming head. Flea beetles are the earlier threat, riddling young transplants with pinpricks before there's much leaf to spare, and a row cover set in place at the transplant date and kept there through early head formation keeps them off without any spray at all.
Aphids that colonize down inside a tightening head are hard to reach with any spray without also coating the part you're about to eat, so a lot of Massachusetts growers treat it as a kitchen problem instead of a field one: florets split apart and soaked in salted water for about 15 minutes float trapped aphids out from between the clusters before cooking, which works more reliably than trying to spray them loose outdoors.
In Massachusetts: watch for
The pests that find broccoli here.
A middle-length season, about 181 frost-free days, means broccoli overlaps cabbage worms & loopers for a stretch each summer. Check plants every week or two and treat early.
Green caterpillars chewing ragged holes; green droppings.
Organic fix: Handpick, cover with netting, spray Bt.
Gray-green clusters tucked into the leaf folds.
Organic fix: Blast with water, then insecticidal soap.
Tiny holes peppering the young leaves.
Organic fix: Row cover from day one; diatomaceous earth.
Black rot
Yellow V-shaped wedges cutting in from the leaf edge, veins blackening inside.
Organic fix: Pull infected plants, water at the base, keep brassicas out of that bed 3 years.
Seedlings wilt, yellow and stall for no reason; white maggots tunnel the roots.
Organic fix: Row cover before the flies are up, when yellow rocket blooms; rotate the bed.
Your season math: Massachusetts gives broccoli about 181 frost-free days, and it needs roughly 60 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting broccoli in Massachusetts: questions
When should I plant broccoli in Massachusetts?+
In a typical Massachusetts year, sow broccoli or set out transplants between Mar 1 to Mar 29, keyed to the state's median last frost around Apr 22. There's also a fall window: Jul 6 to Aug 15. Your exact dates shift with your ZIP code and microclimate.
When do I start broccoli seeds indoors in Massachusetts?+
Start seeds inside about 6 weeks before set-out: roughly Jan 18 to Feb 15 for a typical Massachusetts season.
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 broccoli 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.