Generally — Most Areas
black mustard (zones 6-10) suits most of Missouri (5b-8a) — zones 6-8 are in range, and the rest of the state is the exception.
Black Mustard in Missouri — the short answer
Black Mustard in Missouri: hardy in zones 6–10, full sun, against a state median of ~219 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
- Missouri zones
- 5b-8a
- USDA PHZM 2023
- Frost window
- Mar 27 - Apr 2 – Oct 31 - Nov 7
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 192 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 Missouri site runs ~219 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.
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Missouri is not one climate
A single Missouri answer averages 115 counties whose growing seasons are 66 days apart — from 192 frost-free days in Crawford County to 258 in Pemiscot County. Which end of that your land sits nearer changes what black mustard can finish before the first hard freeze.
The middle half of 115 counties runs 211–225 days, with a median of 219 days — a 66-day span end to end.
Measured across 115 Missouri 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 Missouri Fits Best
Black Mustard is rated for zones 6–10 — a cold floor USDA puts at -10 to 0°F. Against Missouri’s 115 counties that band holds in 110 of them, and the line runs at Adair County (zone 6a), the coldest county still inside it.
Inside zones 6–10
110 counties
- Andrew County · zone 6a
- Buchanan County · zone 6a
- Caldwell County · zone 6a
3 of 110 shown
Below the zone 6 floor
5 counties
- Atchison County · zone 5b
- Harrison County · zone 5b
- Nodaway County · zone 5b
3 of 5 shown
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 Missouri's zones 5b-8a, 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
Missouri Has
- USDA Zones: 5b-8a
- Last Hard Freeze (28°F): Mar 27 - Apr 2
- First Hard Freeze (28°F): Oct 31 - Nov 7
- Annual Rainfall: 34-50 inches
- Common Soils: Silt loam, Clay loam, Loess
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 Missouri
The frost window
Across Missouri, the last spring hard freeze (28°F) clears between Mar 27 and Apr 2, and the first fall hard freeze lands between Oct 31 and Nov 7 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 212-day window you can count on — up to 225 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 152 days to spare even in Missouri'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 Missouri, 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 Missouri site sees ~219 (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 Missouri's silt loam and clay 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 Missouri soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Missouri 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. Missouri 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 Missouri
Zone compatibility tells you about winter cold survival — but Missouri growers also need to think about:
Highly variable weather with late frosts and early heat
Heavy clay soils in many regions
Ozark soils are thin and rocky
What to actually do about these — and the constraints that apply to every Missouri grower, not just black mustard — is covered on the Missouri growing guide.
Timing shifts within Missouri
Black Mustard needs about 120 days of frost-free season to complete its cycle. Even Crawford County — Missouri’s shortest season at 192 frost-free days — clears that by 72 days, so season length isn’t the constraint anywhere in Missouri. What varies is your own parcel.
Across Missouri’s 115 counties the frost-free season runs from 192 days in Crawford County to 258 days in Pemiscot County — a spread of 66 days, which is why a single statewide planting date misleads. The median Missouri county sees 219 frost-free days, leaving black mustard about 99 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 Missouri's frost window — roughly 219 days, opening after the last 28°F freeze (Mar 27 - Apr 2) and closing at the first (Oct 31 - Nov 7), per NOAA Regional Climate Centers ACIS, 1991-2020.
Missouri Cooperative Extension
For Missouri-specific cultivar recommendations, planting calendars, and pest pressure for black mustard, the canonical source is MU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Black Mustard native to Missouri?
No — the USDA PLANTS Database lists Black Mustard as introduced rather than native in the Lower 48, so it is not part of Missouri's native flora. It grows here as a garden plant; pairing it with a few Missouri natives keeps local pollinators fed too.
Looking for plants that belong here? The Missouri 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 Missouri
When can I plant Black Mustard in Missouri?
Missouri's last spring hard freeze (28°F) clears between Mar 27 and Apr 2, and the first fall hard freeze lands between Oct 31 and Nov 7 (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 Missouri?
Yes — Black Mustard matures in 60 days (Growable Ground Plant Database), and Missouri's dependable hard-freeze-free window runs 212 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 152 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 Missouri?
Missouri spans USDA hardiness zones 5b-8a (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 Missouri site have?
A typical Missouri site sees ~219 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 Missouri?
No — the USDA PLANTS Database lists Black Mustard as introduced rather than native in the Lower 48, so it is not part of Missouri's native flora. It grows here as a garden plant; pairing it with a few Missouri natives keeps local pollinators fed too.
How should I amend the soil for Black Mustard in Missouri?
Black Mustard prefers pH 5.3-7.8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Missouri 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 Missouri?
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 Missouri
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 Missouri black mustard averages can't show:
We read public map data around Missouri — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Missouri black mustard average
Explore More
Growing guides for black mustard
Explore Missouri county by county
Missouri carries 115 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 Missouri 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 Missouri
Missouri has a growing page for 893 plants — a rotating sample of the rest of the shelf.
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