Massachusetts · zones 5a–7a
When to plant kale in Massachusetts.
Sow or transplant between Mar 15 to Apr 12 in a typical year, keyed to Massachusetts's median last frost around Apr 22. A second, fall sowing fits Jul 20 to Sep 4. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Kale dates for a typical Massachusetts season.
1 · Start indoors
Feb 1 to Mar 1
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Mar 15 to Apr 12
Keyed to the ~Apr 22 last frost. Sow 0.25" deep, 16" apart.
Fall round
Jul 20 to Sep 4
Counted back from the ~Oct 20 first frost.
Harvest
~45 days later
~2 lb per plant over ~16 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 frost makes kale better, not worse.
Cold sweetens the leaf, and CSA farms plan around it
Kale converts stored starch to sugar once temperatures drop, the same shift that sweetens fall carrots, and Massachusetts CSA farms often deliberately hold their last kale harvest of the season until after the first hard frost specifically to catch that flavor change rather than picking early out of caution.
The plant itself shrugs off cold that ends most of the garden; a stand still standing green through nights in the 20s while everything around it has blackened is normal here, and growers routinely stretch a kale harvest well into late fall on the strength of that hardiness alone.
Berkshire till versus Cape sand changes the watering rhythm
Western Massachusetts gardens on heavier glacial till hold moisture for days after a rain, while Cape Cod and Islands gardens on sandy, fast-draining ground dry out again within a day or two of the same storm. Kale wilts visibly under drought stress well before it actually suffers real damage, so a sandy-soil grower watching for that first droop catches trouble earlier than a till-soil grower who can often go by the feel of the ground instead.
A couple of inches of compost dug into either soil type before transplanting pays off over kale's long harvest window, since it is a heavy leafy feeder and thin ground runs short on nitrogen well before the plant runs out of season to use it.
Flea beetles hit hardest on the youngest leaves
Flea beetles shot-hole young kale transplants before the plant has leaf area to spare any of it. A lightweight cover set over the bed at transplant and kept there for the seedling's first few vulnerable weeks stops them from ever landing, no spray needed; established plants shrug off the same damage with barely a dent in the eventual harvest.
Cabbage worms and loopers show up later, chewing ragged notches into the leaf edges and leaving fine, dark droppings behind on the underside; handpicking whatever turns up during a weekly walk down the row keeps a kale bed clean enough to eat raw after nothing more than a normal rinse.
In Massachusetts: watch for
The pests that find kale here.
A middle-length season, about 181 frost-free days, means kale 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 kale about 181 frost-free days, and it needs roughly 45 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting kale in Massachusetts: questions
When should I plant kale in Massachusetts?+
In a typical Massachusetts year, sow kale or set out transplants between Mar 15 to Apr 12, keyed to the state's median last frost around Apr 22. There's also a fall window: Jul 20 to Sep 4. Your exact dates shift with your ZIP code and microclimate.
When do I start kale seeds indoors in Massachusetts?+
Start seeds inside about 6 weeks before set-out: roughly Feb 1 to Mar 1 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 kale 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.