Yes — Strong Match
mustard cover crop (zones 3-10) covers every zone Oregon contains (5a-10a), so hardiness is not what limits it anywhere in the state.
Mustard Cover Crop in Oregon — the short answer
Mustard Cover Crop in Oregon: hardy in zones 3–10, full sun, against a state median of ~213 frost-free days.
- Plant zones
- 3-10
- 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
- Oregon zones
- 5a-10a
- USDA PHZM 2023
- Frost window
- Feb 25 - Apr 26 – Oct 19 - Nov 26
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 86 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 50 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.
Mustard Cover Crop is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Oregon site runs ~213 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 mustard cover crop against your land's actual frost dates, sun, and soil.
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Oregon is not one climate
A single Oregon answer averages 36 counties whose growing seasons are 222 days apart — from 86 frost-free days in Klamath County to 308 in Lincoln County. Which end of that your land sits nearer changes what mustard cover crop can finish before the first hard freeze.
The middle half of 36 counties runs 165–274 days, with a median of 212 days — a 222-day span end to end.
Measured across 36 Oregon 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 Oregon Fits Best
Even within Oregon's zones 5a-10a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for mustard cover crop (USDA PHZM 2023):
Zone Comparison
Mustard Cover Crop Needs
- USDA Zones: 3-10
- Frost-Free Days: 110+
- Sun: Full Sun
- Mature size: 4 ft tall
- Drought tolerance: Medium
Oregon Has
- USDA Zones: 5a-10a
- Last Hard Freeze (28°F): Feb 25 - Apr 26
- First Hard Freeze (28°F): Oct 19 - Nov 26
- Annual Rainfall: 8-90 inches
- Common Soils: Volcanic, Silt loam (Willamette), Sandy loam
Plant Zone Range (zones 3-10)
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 Mustard Cover Crop in Oregon
The frost window
Across Oregon, the last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 176-day window you can count on — up to 274 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 hardiness
Mustard Cover Crop takes cold down to about 25°F before a freeze kills it (FAO ECOCROP), so you can plant on the early side of Oregon's window — even a few weeks before the final hard freeze. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.
When to start the seed
Mustard Cover Crop is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Oregon'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 50 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 126 days to spare even in Oregon'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 mustard cover crop survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Mustard Cover Crop wants 110+ frost-free days; a typical Oregon site sees ~213 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Mustard Cover Crop needs ~900 GDD (base 50°F) to ripen. The state median runs ~1666 GDD (from PRISM 1991-2020 climate normals), so Oregon'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
Mustard Cover Crop tolerates a wide pH range (pH 5.5-8.5) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Oregon. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 6.5 and 7.5 — worth knowing before you decide whether a Oregon soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Oregon 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. Oregon soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Mustard Cover Crop in Oregon
Zone compatibility tells you about winter cold survival — but Oregon growers also need to think about:
West side: excessive rain and overcast skies reduce sun for warm-season crops
East side: arid conditions (8-15 inches rainfall) require irrigation
Slug pressure is extreme in western Oregon
Mountain areas have very short seasons (60-90 frost-free days)
What to actually do about these — and the constraints that apply to every Oregon grower, not just mustard cover crop — is covered on the Oregon growing guide.
Timing shifts within Oregon
Mustard Cover Crop needs about 110 days of frost-free season to complete its cycle. 35 of Oregon’s 36 counties give it that outright. The tightest that does is Lake County at 134 frost-free days — 24 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Oregon’s 36 counties the frost-free season runs from 86 days in Klamath County to 308 days in Lincoln County — a spread of 222 days, which is why a single statewide planting date misleads. The median Oregon county sees 213 frost-free days, leaving mustard cover crop about 103 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"). Mustard Cover Crop's 110-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
Mustard Cover Crop draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, mustard cover crop can only work that bloom inside Oregon's frost window — roughly 213 days, opening after the last 28°F freeze (Feb 25 - Apr 26) and closing at the first (Oct 19 - Nov 26), per NOAA Regional Climate Centers ACIS, 1991-2020.
Oregon Cooperative Extension
For Oregon-specific cultivar recommendations, planting calendars, and pest pressure for mustard cover crop, the canonical source is OSU Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Mustard Cover Crop native to Oregon?
No — the USDA PLANTS Database lists Mustard Cover Crop as introduced rather than native in the Lower 48, so it is not part of Oregon's native flora. It grows here as a garden plant; pairing it with a few Oregon natives keeps local pollinators fed too.
Looking for plants that belong here? The Oregon 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 Mustard Cover Crop in Oregon
When can I plant Mustard Cover Crop in Oregon?
Oregon's last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). Mustard Cover Crop takes cold to about 25°F before a freeze kills it (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor), so plant on the early side of that window — even ahead of the final hard freeze.
Can Mustard Cover Crop mature before first frost in Oregon?
Yes — Mustard Cover Crop matures in 50 days (Growable Ground Plant Database), and Oregon's dependable hard-freeze-free window runs 176 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 126 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 Mustard Cover Crop grown in across Oregon?
Oregon spans USDA hardiness zones 5a-10a (USDA ARS PHZM 2023). Mustard Cover Crop carries a range of zones 3-10, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Oregon site have?
A typical Oregon site sees ~213 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Mustard Cover Crop needs 110+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Mustard Cover Crop native to Oregon?
No — the USDA PLANTS Database lists Mustard Cover Crop as introduced rather than native in the Lower 48, so it is not part of Oregon's native flora. It grows here as a garden plant; pairing it with a few Oregon natives keeps local pollinators fed too.
How should I amend the soil for Mustard Cover Crop in Oregon?
Mustard Cover Crop tolerates pH 5.5-8.5 and well (dry spells) drainage (FAO ECOCROP). That is a 3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Oregon site — amend for drainage and organic matter first.
Will Mustard Cover Crop actually grow on my specific land in Oregon?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores mustard cover crop 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 Oregon
State-level data is a sketch. Your Growable Ground report scores mustard cover crop against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Oregon mustard cover crop averages can't show:
We read public map data around Oregon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oregon mustard cover crop average
Explore More
Growing guides for mustard cover crop
Explore Oregon county by county
Oregon carries 36 counties with their own USDA zone — a sample of the growing pages for mustard cover crop there:
Where else mustard cover crop grows
Mustard Cover Crop's zone band crosses state lines — these are the states closest to Oregon 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 Oregon
Oregon has a growing page for 1,038 plants — a rotating sample of the rest of the shelf.
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