Can I Grow Black Mustard in South Dakota?

USDA Zones 4a-5b · Plant zone range 6-10

Unlikely — Zone Mismatch

black mustard (zones 6-10) does not overlap with South Dakota's zone range (4a-5b). Growing outdoors is unlikely without significant protection.

One zone short — what would close it

Black Mustard is hardy to zone 6, and the warmest ground in South Dakota is zone 5 — 1 zone short. Planted in open ground it will not survive a South Dakota winter. To grow it here, grow black mustard in a container and move it under cover for the coldest weeks, or give it a greenhouse.

Season extension and overwintering under cover both work at this margin. How to buy the weeks →

Zone math from 6-10 (plant) against 4-5 (South Dakota). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.

Score your parcel · free

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 South Dakota site runs ~168 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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Zone Comparison

Black Mustard Needs

  • USDA Zones: 6-10
  • Frost-Free Days: 120+
  • Sun: Full Sun
  • Mature size: 4 ft tall

South Dakota Has

  • USDA Zones: 4a-5b
  • Last Hard Freeze (28°F): Apr 22 - Apr 29
  • First Hard Freeze (28°F): Oct 9 - Oct 15
  • Annual Rainfall: 14-26 inches
  • Common Soils: Prairie loam, Clay, Sandy loam

Plant Zone Range (zones 6-10)

6a
10b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.37.8

Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Black Mustard in South Dakota

The frost window

Across South Dakota, the last spring hard freeze (28°F) clears between Apr 22 and Apr 29, and the first fall hard freeze lands between Oct 9 and Oct 15 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 163-day window you can count on — up to 176 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.

Frost tenderness

Black Mustard is frost-tender — its listed minimum temperature is 41°F (USDA PLANTS Database) — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does.

Days to maturity vs. the window

At 60 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 103 days to spare even in South Dakota's tightest freeze scenario — room for a later start or a second sowing.

Timing tuned to sub-state frost dates — Lawrence 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 mustard does not survive a South Dakota winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on South Dakota under protection.

Frost-free days

Black Mustard wants 120+ frost-free days; a typical South Dakota site sees ~168 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a workable window — start indoors to bank time.

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 South Dakota's prairie loam and clay — 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 South Dakota soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your South Dakota site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Your land, not the state average

South Dakota's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Black Mustard needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how black mustard performs.

Check your parcel → Source: USDA NRCS SSURGO.

Plant pH and drainage requirements from USDA PLANTS Database. South Dakota soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Black Mustard in South Dakota — Quick Answer

  • Verdict: Unlikely — Zone Mismatch
  • Plant Zones: 6-10 (USDA PLANTS Database)
  • State Zones: 4a-5b (USDA ARS PHZM 2023)
  • Growing Season: 28°F hard freezes about Apr 22 - Apr 29 to Oct 9 - Oct 15 (NOAA Regional Climate Centers ACIS, 1991-2020)
  • Days to Maturity: 60 days

What Else to Consider for Black Mustard in South Dakota

Zone compatibility tells you about winter cold survival — but South Dakota growers also need to think about:

Extreme cold and short growing season

Low rainfall in western SD

Wind exposure on the open prairie

Growing black mustard here specifically

South Dakota's soils run mostly loam (Mollisols), and whether that suits black mustard's pH 5.3–7.8 preference comes down to your exact parcel, not the statewide picture.

Pull your parcel's SSURGO map unit, test pH, and amend toward black mustard's 5.3–7.8 target before planting. How to handle it →

What to actually do about these — and the constraints that apply to every South Dakota grower, not just black mustard — is covered on the South Dakota growing guide.

Timing shifts within South Dakota

South Dakota isn't one climate. In Lawrence County, the last hard freeze (28°F) holds until about May 12 — roughly 17 days later than the recorded state median — so plant black mustard to your county's window, not the statewide date.

Black Mustard needs about 120 days of frost-free season to complete its cycle. Even Lawrence County — South Dakota’s shortest season at 145 frost-free days — clears that by 25 days, so season length isn’t the constraint anywhere in South Dakota. What varies is your own parcel.

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 South Dakota's frost window — roughly 168 days, opening after the last 28°F freeze (Apr 22 - Apr 29) and closing at the first (Oct 9 - Oct 15), per NOAA Regional Climate Centers ACIS, 1991-2020.

South Dakota Cooperative Extension

For South Dakota-specific cultivar recommendations, planting calendars, and pest pressure for black mustard, the canonical source is SDSU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Black Mustard native to South Dakota?

No — the USDA PLANTS Database lists Black Mustard as introduced rather than native in the Lower 48, so it is not part of South Dakota's native flora. It grows here as a garden plant; pairing it with a few South Dakota natives keeps local pollinators fed too.

Looking for plants that belong here? The South Dakota 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 South Dakota

When can I plant Black Mustard in South Dakota?

South Dakota's last spring hard freeze (28°F) clears between Apr 22 and Apr 29, and the first fall hard freeze lands between Oct 9 and Oct 15 (NOAA Regional Climate Centers ACIS, 1991-2020). Black Mustard is frost-tender — its listed minimum temperature is 41°F (USDA PLANTS Database) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.

Can Black Mustard mature before first frost in South Dakota?

Yes — Black Mustard matures in 60 days (USDA PLANTS Database), and South Dakota's dependable hard-freeze-free window runs 163 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 103 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 South Dakota?

South Dakota spans USDA hardiness zones 4a-5b (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 South Dakota site have?

A typical South Dakota site sees ~168 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. In cooler counties like Lawrence, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Black Mustard native to South Dakota?

No — the USDA PLANTS Database lists Black Mustard as introduced rather than native in the Lower 48, so it is not part of South Dakota's native flora. It grows here as a garden plant; pairing it with a few South Dakota natives keeps local pollinators fed too.

How should I amend the soil for Black Mustard in South Dakota?

Black Mustard prefers pH 5.3-7.8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across South Dakota 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 South Dakota?

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.

Free Report

Check your specific parcel in South Dakota

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 South Dakota black mustard averages can't show:

Your soil pHYour frost-free days — South Dakota averages 168Your sun & shade

We read public map data around South Dakota — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the South Dakota black mustard average

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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