Generally — Most Areas
black mustard (zones 6-10) suits most of Massachusetts (5a-7b) — zones 6-7 are in range, and the rest of the state is the exception.
Black Mustard in Massachusetts — the short answer
Black Mustard in Massachusetts: hardy in zones 6–10, full sun, against a state median of ~206 frost-free days.
- Plant zones
- 6-10
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Massachusetts zones
- 5a-7b
- USDA PHZM 2023
- Frost window
- Apr 4 - Apr 14 – Oct 24 - Nov 14
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 171 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 60 days
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Black Mustard is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Massachusetts site runs ~206 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score black mustard against your land's actual frost dates, sun, and soil.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Massachusetts is not one climate
A single Massachusetts answer averages 14 counties whose growing seasons are 75 days apart — from 171 frost-free days in Berkshire County to 246 in Nantucket County. Which end of that your land sits nearer changes what black mustard can finish before the first hard freeze.
The middle half of 14 counties runs 193–226 days, with a median of 205 days — a 75-day span end to end.
Measured across 14 Massachusetts counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where in Massachusetts Fits Best
Black Mustard is rated for zones 6–10 — a cold floor USDA puts at -10 to 0°F. Against Massachusetts’s 14 counties that band holds in 13 of them, and the line runs at Franklin County (zone 6a), the coldest county still inside it.
Inside zones 6–10
13 counties
- Hampshire County · zone 6a
- Worcester County · zone 6a
- Essex County · zone 6b
3 of 13 shown
Below the zone 6 floor
1 county
- Berkshire County · zone 5b
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Even within Massachusetts's zones 5a-7b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for black mustard (USDA PHZM 2023):
Zone Comparison
Black Mustard Needs
- USDA Zones: 6-10
- Frost-Free Days: 120+
- Sun: Full Sun
- Mature size: 4 ft tall
Massachusetts Has
- USDA Zones: 5a-7b
- Last Hard Freeze (28°F): Apr 4 - Apr 14
- First Hard Freeze (28°F): Oct 24 - Nov 14
- Annual Rainfall: 42-50 inches
- Common Soils: Glacial till, Sandy loam, Rocky loam
Plant Zone Range (zones 6-10)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Black Mustard in Massachusetts
The frost window
Across Massachusetts, the last spring hard freeze (28°F) clears between Apr 4 and Apr 14, and the first fall hard freeze lands between Oct 24 and Nov 14 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 193-day window you can count on — up to 224 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Days to maturity vs. the window
At 60 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 133 days to spare even in Massachusetts's tightest freeze scenario — room for a later start or a second sowing.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says black mustard survives winter in part of Massachusetts, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Black Mustard wants 120+ frost-free days; a typical Massachusetts site sees ~206 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Black Mustard likes near-neutral soil (pH 5.3-7.8). That's the common-ground band across Massachusetts's glacial till and sandy loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 7 — worth knowing before you decide whether a Massachusetts soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Massachusetts site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Massachusetts soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Black Mustard in Massachusetts
Zone compatibility tells you about winter cold survival — but Massachusetts growers also need to think about:
Short growing season (120-180 frost-free days) limits warm-season crops
Rocky glacial soils require amendment in many areas
Late spring frosts can damage early plantings through mid-May
Deer pressure is significant in suburban and rural areas
What to actually do about these — and the constraints that apply to every Massachusetts grower, not just black mustard — is covered on the Massachusetts growing guide.
Timing shifts within Massachusetts
Black Mustard needs about 120 days of frost-free season to complete its cycle. Even Berkshire County — Massachusetts’s shortest season at 171 frost-free days — clears that by 51 days, so season length isn’t the constraint anywhere in Massachusetts. What varies is your own parcel.
Across Massachusetts’s 14 counties the frost-free season runs from 171 days in Berkshire County to 246 days in Nantucket County — a spread of 75 days, which is why a single statewide planting date misleads. The median Massachusetts county sees 206 frost-free days, leaving black mustard about 86 days of slack on a typical parcel — room for a second sowing where the season runs long.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Black Mustard's 120-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Black Mustard draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, black mustard can only work that bloom inside Massachusetts's frost window — roughly 206 days, opening after the last 28°F freeze (Apr 4 - Apr 14) and closing at the first (Oct 24 - Nov 14), per NOAA Regional Climate Centers ACIS, 1991-2020.
Massachusetts Cooperative Extension
For Massachusetts-specific cultivar recommendations, planting calendars, and pest pressure for black mustard, the canonical source is UMass Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Black Mustard native to Massachusetts?
No — the USDA PLANTS Database lists Black Mustard as introduced rather than native in the Lower 48, so it is not part of Massachusetts's native flora. It grows here as a garden plant; pairing it with a few Massachusetts natives keeps local pollinators fed too.
Looking for plants that belong here? The Massachusetts growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Black Mustard in Massachusetts
When can I plant Black Mustard in Massachusetts?
Massachusetts's last spring hard freeze (28°F) clears between Apr 4 and Apr 14, and the first fall hard freeze lands between Oct 24 and Nov 14 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
Can Black Mustard mature before first frost in Massachusetts?
Yes — Black Mustard matures in 60 days (Growable Ground Plant Database), and Massachusetts's dependable hard-freeze-free window runs 193 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 133 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Black Mustard grown in across Massachusetts?
Massachusetts spans USDA hardiness zones 5a-7b (USDA ARS PHZM 2023). Black Mustard carries a range of zones 6-10, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Massachusetts site have?
A typical Massachusetts site sees ~206 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Black Mustard needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Black Mustard native to Massachusetts?
No — the USDA PLANTS Database lists Black Mustard as introduced rather than native in the Lower 48, so it is not part of Massachusetts's native flora. It grows here as a garden plant; pairing it with a few Massachusetts natives keeps local pollinators fed too.
How should I amend the soil for Black Mustard in Massachusetts?
Black Mustard prefers pH 5.3-7.8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Massachusetts soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Black Mustard actually grow on my specific land in Massachusetts?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores black mustard against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Massachusetts
State-level data is a sketch. Your Growable Ground report scores black mustard against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Massachusetts black mustard averages can't show:
We read public map data around Massachusetts — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Massachusetts black mustard average
Explore More
Growing guides for black mustard
Explore Massachusetts county by county
Massachusetts carries 14 counties with their own USDA zone — a sample of the growing pages for black mustard there:
Where else black mustard grows
Black Mustard's zone band crosses state lines — these are the states closest to Massachusetts in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Massachusetts
Massachusetts has a growing page for 893 plants — a rotating sample of the rest of the shelf.
Last updated: