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USDA hardiness zone lookup

Boston, MA — USDA Zone 7a

Boston, Massachusetts · 189-day growing season

Frost dates and growing season in Boston

USDA hardiness zoneZone 7a
Average last spring frostApril 26
Average first fall frostNovember 1
Growing season length~189 days
Temperature range (F)0 to 10°F
Temperature range (C)-18 to -12°C

All of Boston's mapped ZIP codes fall in the same hardiness band, Zone 7a.

These are 50%-probability averages modeled from Boston's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by April 26, but a colder-than-average year can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.

Growing season in Boston

Boston, Massachusetts sits in USDA Zone 7a, with roughly 189 frost-free days between an average last spring frost around April 26 and a first fall frost around November 1. That is a long season — succession-sow through summer and run a full fall crop; heat-sensitive greens still need spring/autumn timing. Boston lies near 42.4°N; higher-latitude gardens get longer midsummer days but a tighter shoulder season at this zone. As a large metro, the built-up core typically runs up to half a zone warmer than outlying suburbs through the urban heat-island effect — sheltered city gardens often push tender crops a little earlier than the average suggests.

What grows in Boston

Boston falls in USDA Zone 7a, so the same hardiness constraints apply as the full Zone 7 guide. Vegetables, herbs, and fruit trees rated to Zone 7a (or hardier) will overwinter here in a typical year.

What to plant in Boston this week

Boston is in high summer — most spring plantings are in. Keep an eye on watering and start planning your fall crop. Cool-season seedlings (broccoli, cabbage, lettuce) can be started indoors for a fall transplant.

Full planting calendar for Boston

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 7 averages:

ZIP codes in Boston

Drill down to the precise frost window and planting calendar for a specific ZIP in Boston:

Local microclimate notes

Zone tables give you the average — but Bostongardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record — the last time you actually got frost damage — beats any national average.

Source and methodology

Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from Boston's USDA hardiness zone and regional NOAA 1991-2020 climate normals — zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations draw on US Cooperative Extension references, curated by the Growli editorial team. Last reviewed June 2026.

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