Yes — Strong Match
black seed (zones 5-10) covers every zone Missouri contains (5b-8a), so hardiness is not what limits it anywhere in the state.
Your yard isn't the whole zone.
Black Seed 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 seed against your land's actual frost dates, sun, and soil.
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Zone Comparison
Black Seed Needs
- USDA Zones: 5-10
- Frost-Free Days: 90+
- Sun: Full Sun
- Mature size: 1.3 ft tall
- Picking window: ~21 days of harvest
- Drought tolerance: Medium
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 5-10)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Black Seed 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.
When to start the seed
Black Seed is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Missouri's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.
Days to maturity vs. the window
At 100 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 112 days to spare even in Missouri's tightest freeze scenario — room for a later start or a second sowing.
Timing tuned to sub-state frost dates — Crawford County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. 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 seed survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Black Seed wants 90+ frost-free days; a typical Missouri site sees ~219 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Black Seed needs ~1500 GDD (base 50°F) to ripen. The state median runs ~3770 GDD (from PRISM 1991-2020 climate normals), so Missouri's typical season clears that easily.
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 Seed likes near-neutral soil (pH 5.5-8). 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 7.5 — 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.
Your land, not the state average
Missouri's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for black seed is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how black seed performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Missouri soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Black Seed in Missouri — Quick Answer
- Verdict: Yes — Strong Match
- Plant Zones: 5-10 (USDA PLANTS Database)
- State Zones: 5b-8a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 27 - Apr 2 to Oct 31 - Nov 7 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 100 days
What Else to Consider for Black Seed 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
Growing black seed here specifically
Black Seed needs pH 5.5–8.0; Missouri's dominant silt loam soils may or may not deliver that, so your parcel's SSURGO map unit is the real test.
Start with a soil test on your own ground and adjust pH and texture to fit black seed's 5.5–8.0 range. How to handle it →
What to actually do about these — and the constraints that apply to every Missouri grower, not just black seed — is covered on the Missouri growing guide.
Timing shifts within Missouri
Missouri isn't one climate. In Crawford County, the last hard freeze (28°F) holds until about Apr 10 — roughly 12 days later than the recorded state median — so plant black seed to your county's window, not the statewide date.
Black Seed needs about 90 days of frost-free season to complete its cycle. Even Crawford County — Missouri’s shortest season at 192 frost-free days — clears that by 102 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 seed about 129 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 Seed's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Where in Missouri Fits Best
Even within Missouri's zones 5b-8a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for black seed (USDA PHZM 2023):
Pollinator + Wildlife Value
Black Seed 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 seed 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.
Good to Know Before You Plant Black Seed
Black Seed is listed as toxic to dogs, cats (seeds) at a mild level (Pet Poison Helpline). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Worth knowing for placement: in Missouri this is a one-season plant and the first hard freeze (Oct 31 - Nov 7) takes it down, so the exposure above is a summer-long one rather than something standing in the bed all year.
Recommended Black Seed Varieties for Missouri
Missouri publishes no state variety trial for black seed, so we won't invent a "best for Missouri" list. Choose types rated to your USDA hardiness zone (5b-8a), and confirm winter survival and drainage against your own parcel.
Missouri Cooperative Extension
For Missouri-specific cultivar recommendations, planting calendars, and pest pressure for black seed, the canonical source is MU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Black Seed native to Missouri?
No — the USDA PLANTS Database lists Black Seed 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 Seed in Missouri
When can I plant Black Seed 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 Seed mature before first frost in Missouri?
Yes — Black Seed matures in 100 days (USDA PLANTS Database), and Missouri's dependable hard-freeze-free window runs 212 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 112 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 Seed grown in across Missouri?
Missouri spans USDA hardiness zones 5b-8a (USDA ARS PHZM 2023). Black Seed carries a range of zones 5-10, 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 Seed needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Crawford, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Black Seed native to Missouri?
No — the USDA PLANTS Database lists Black Seed 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 Seed in Missouri?
Black Seed prefers pH 5.5-8 and well (dry spells) drainage (Growable Ground Plant Database). 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 Seed actually grow on my specific land in Missouri?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores black seed 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 seed against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Missouri black seed 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 seed average
Explore More
Growing guides for black seed
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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