Yes — Strong Match
red clover is grown in zones 3-10, which covers every zone Wyoming contains (3b-6a). Whether the season is long enough is the question that remains.
Red Clover in Wyoming — the short answer
Red Clover in Wyoming: grown in zones 3–10, full sun.
- Plant zones
- 3-10
- Not verified — NC State Extension Gardener Plant Toolbox lists zones 3a–9b
- Wyoming zones
- 3b-6a
- USDA PHZM 2023
- Frost window
- May 4 - May 13 – Sep 30 - Oct 7
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 79 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 140 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.
Wyoming spans zones 3b-6a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score red clover against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Wyoming is not one climate
A single Wyoming answer averages 23 counties whose growing seasons are 87 days apart — from 79 frost-free days in Teton County to 166 in Big Horn County. Which end of that your land sits nearer changes what red clover can finish before the first hard freeze.
The middle half of 23 counties runs 136–155 days, with a median of 151 days — a 87-day span end to end.
Measured across 23 Wyoming 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 Wyoming Fits Best
Even within Wyoming's zones 3b-6a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for red clover (USDA PHZM 2023):
Zone Comparison
Red Clover Needs
- USDA Zones: 3-10
- Sun: Full Sun
- Mature size: 2 ft tall
- Drought tolerance: Low
Wyoming Has
- USDA Zones: 3b-6a
- Last Hard Freeze (28°F): May 4 - May 13
- First Hard Freeze (28°F): Sep 30 - Oct 7
- Annual Rainfall: 6-20 inches
- Common Soils: Sandy loam, Clay, Alkaline
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 Red Clover in Wyoming
The frost window
Across Wyoming, the last spring hard freeze (28°F) clears between May 4 and May 13, and the first fall hard freeze lands between Sep 30 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 140-day window you can count on — up to 156 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
Red Clover is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Wyoming'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.
Winter standing
Wyoming runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for red clover, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether red clover is a permanent planting or a replant-every-spring crop for you turns on your own zone within Wyoming; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Teton County, not the statewide average.
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
Red Clover is grown in zones 3–10, which covers every zone Wyoming contains (3b-6a). We have no sourced winter-survival figure for red clover, so this page does not say whether it overwinters here. Wyoming's typical season runs ~151 frost-free days against the ~120 red clover needs.
Growing degree days
Red Clover needs ~1800 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~1866 GDD (from PRISM 1991-2020 climate normals), so Wyoming sits right at the threshold — pay attention to siting and microclimate.
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
Red Clover tolerates a wide pH range (pH 4.5-8.2) — 3.7 units, acid ground through alkaline — so soil acidity is rarely what limits it in Wyoming. 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 and 7.5 — worth knowing before you decide whether a Wyoming soil test result is a problem or just a number. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your Wyoming site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost.
Your land, not the state average
Wyoming's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Red Clover 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 red clover performs.
Check your parcel → Source: USDA NRCS SSURGO.
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. Wyoming soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Red Clover in Wyoming
The zone range tells you where red clover is grown — but Wyoming growers also need to think about:
Extremely short growing season (60-90 frost-free days)
Very low rainfall requires irrigation
Persistent high winds desiccate and damage plants
Growing red clover here specifically
Red Clover takes ~140 days and rates to zones 3–10; against Wyoming's ~151 frost-free days, timing is everything.
Buy red clover weeks with an early indoor sowing and season-extending covers. How to handle it →
What to actually do about these — and the constraints that apply to every Wyoming grower, not just red clover — is covered on the Wyoming growing guide.
Timing shifts within Wyoming
Wyoming isn't one climate. In Teton County, the last hard freeze (28°F) holds until about Jun 16 — roughly 41 days later than the recorded state median — so plant red clover to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Wyoming Red Clover Is Zone-Hardy
Red Clover is rated for USDA zones 3–10. Every one of Wyoming’s 23 counties sits inside that band — from Albany County at zone 4b to Uinta County at zone 5b — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.
Across those 23 counties Wyoming’s winter-low ladder runs from zone 4b in Albany County to zone 5b in Uinta County — 1 USDA zone of spread, which is 10°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.
The planting window moves with it. Teton County holds its last hard freeze (28°F) until about Jun 16, while Big Horn County is clear by Apr 26 — 51 days apart. Set red clover out on your county’s date, not the state’s.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". Red Clover’s zone 3–10 band: Not verified — NC State Extension Gardener Plant Toolbox lists zones 3a–9b. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Red Clover draws honeybees, native bees, and butterflies (high value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, red clover can only work that bloom inside Wyoming's frost window — roughly 151 days, opening after the last 28°F freeze (May 4 - May 13) and closing at the first (Sep 30 - Oct 7), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.
Wyoming Cooperative Extension
For Wyoming-specific cultivar recommendations, planting calendars, and pest pressure for red clover, the canonical source is University of Wyoming Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Red Clover native to Wyoming?
No — the USDA PLANTS Database lists Red Clover as introduced rather than native in the Lower 48, so it is not part of Wyoming's native flora. It grows here as a garden plant; pairing it with a few Wyoming natives keeps local pollinators fed too.
Looking for plants that belong here? The Wyoming growing guide lists plants that USDA PLANTS records growing in Wyoming and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.
State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.
Common Questions About Growing Red Clover in Wyoming
When can I plant Red Clover in Wyoming?
Wyoming's last spring hard freeze (28°F) clears between May 4 and May 13, and the first fall hard freeze lands between Sep 30 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Red Clover, so this page does not state whether it overwinters in Wyoming and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Red Clover grown in across Wyoming?
Wyoming spans USDA hardiness zones 3b-6a (USDA ARS PHZM 2023). Red Clover 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 Wyoming site have?
A typical Wyoming site sees ~151 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Red Clover 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 Teton, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Red Clover native to Wyoming?
No — the USDA PLANTS Database lists Red Clover as introduced rather than native in the Lower 48, so it is not part of Wyoming's native flora. It grows here as a garden plant; pairing it with a few Wyoming natives keeps local pollinators fed too.
How should I amend the soil for Red Clover in Wyoming?
Red Clover tolerates pH 4.5-8.2 and poorly (saturated >50% of year), well (dry spells) drainage (FAO ECOCROP). That is a 3.7-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Wyoming site — amend for drainage and organic matter first.
Will Red Clover actually grow on my specific land in Wyoming?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores red clover against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Wyoming
State-level data is a sketch. Your Growable Ground report scores red clover against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Wyoming red clover averages can't show:
We read public map data around Wyoming — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wyoming red clover average
Explore More
Growing guides for red clover
Explore Wyoming county by county
Wyoming carries 23 counties with their own USDA zone — a sample of the growing pages for red clover there:
Where else red clover grows
Red Clover's zone band crosses state lines — these are the states closest to Wyoming 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 Wyoming
Wyoming has a growing page for 807 plants — a rotating sample of the rest of the shelf.
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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