French lavender (Lavandula stoechas), photographi

Can I Grow French Lavender in Wyoming?

USDA Zones 3b-6a · Plant zone range 8-9

Unlikely — Zone Mismatch

French lavender (zones 8-9) does not overlap with Wyoming's zone range (3b-6a). Growing outdoors is unlikely without significant protection.

2 zones short — what would close it

French Lavender is hardy to zone 8, and the warmest ground in Wyoming is zone 6 — 2 zones short. Planted in open ground it will not survive a Wyoming winter. To grow it here, grow french lavender in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.

An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →

Zone math from 8-9 (plant) against 3-6 (Wyoming). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.

French Lavender in Wyoming — the short answer

French Lavender in Wyoming: hardy in zones 8–9, full sun, against a state median of ~151 frost-free days.

Plant zones
8-9
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
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
90 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.

Score your parcel · free

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 french lavender 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.

No card required · your full report in seconds

Wyoming is not one climate

Wyoming’s winter-low ladder runs across 23 counties, from zone 4.5 in Albany County to zone 5.5 in Uinta County. That is 10°F between the two counties’ average coldest night — the difference between french lavender overwintering in the ground and coming under cover.

4.5 zonesAlbany County5.5 zonesUinta County

The middle half of 23 counties runs 4.55 zones, with a median of 5 zones — a 1-zone span end to end.

Measured across 23 Wyoming counties. USDA PHZM 2023, per county. 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 French Lavender Stands in Wyoming

French Lavender is rated for zones 89 — a cold floor USDA puts at 10 to 20°F. No Wyoming county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Wyoming winters, not about french lavender.

Below the zone 8 floor

23 counties

3 of 23 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.

Zone Comparison

French Lavender Needs

  • USDA Zones: 8-9
  • Frost-Free Days: 180+
  • Sun: Full Sun
  • Mature size: 2 ft tall
  • Picking window: ~30 days of harvest
  • Drought tolerance: High

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 8-9)

8a
9b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.88.3

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 French Lavender 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

Those dates are when french lavender goes out, not when it starts. It is sown under cover about 10 weeks ahead, so counting back from Wyoming's late-side last freeze of May 13 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Winter standing

French Lavender overwinters from USDA zone 8 and warmer (NC State Extension Gardener Plant Toolbox; Missouri Botanical Garden Plant Finder), and Wyoming runs as cold as zone 3, so it does not survive winter in the ground here. It is a woody plant rather than a crop you resow each spring, so neither a fall establishment date nor a harvest countdown describes it in Wyoming — which is why this page gives neither. What it needs here is a way through winter, not a planting date.

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

The zone check says french lavender does not survive a Wyoming 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 Wyoming under protection.

Frost-free days

French Lavender wants 180+ frost-free days; a typical Wyoming site sees ~151 (NOAA Regional Climate Centers ACIS, 1991-2020) — 29 days short of what it needs. A typical Wyoming season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.

Growing degree days

French Lavender needs ~1200 GDD (base 50°F) to ripen. The state median runs ~1866 GDD (from PRISM 1991-2020 climate normals), so Wyoming'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

French Lavender likes near-neutral soil (pH 5.8-8.3). That's the common-ground band across Wyoming's sandy loam and clay — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6.5 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 well (dry spells), excessive (dry/moderately dry). If your Wyoming site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Your land, not the state average

Wyoming's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. French Lavender needs about 59 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 french lavender 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.

Before you plant french lavender for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before french lavender goes in. What follows is Wyoming’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Wyoming — and how to grow with it.

Federal record: High

We checked the federal record across Wyoming10,910 documented sites across 8 of the 9 source types we track.

The most significant on record: 64 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Wyoming carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across Wyoming

Severity Distribution

across Wyoming

High42Moderate5,938Low4,930

Highest-Severity Sites

Mining Sites · Past Producer
Superfund · Superfund NPL
PFAS Sampling · PFAS Detected
Mining Sites · Past Producer
Mining Sites · Past Producer

A note from Gnorman

What an experienced grower watches for around here

In and around Wyoming, Nitrate runs higher than the national average — 4,750 sites across Wyoming. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for French Lavender in Wyoming

Zone compatibility tells you about winter cold survival — 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 french lavender here specifically

French Lavender prefers pH 5.8–8.3 and room to root deep; across much of Wyoming, restrictive group-D subsoil (SSURGO) blocks that depth.

Build french lavender a deep raised bed of loose soil to bypass the dense subsoil entirely. How to handle it →

What to actually do about these — and the constraints that apply to every Wyoming grower, not just french lavender — 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 french lavender to your county's window, not the statewide date.

French Lavender needs about 180 days of frost-free season to complete its cycle. No Wyoming county gives it that outdoors: even Big Horn County, the state’s longest season at 166 frost-free days, falls 14 days short — so it needs transplants, a short-season variety, or covered growing.

Across Wyoming’s 23 counties the frost-free season runs from 79 days in Teton County to 166 days in Big Horn County — a spread of 87 days, which is why a single statewide planting date misleads. The median Wyoming county sees 151 frost-free days, which is 29 days short of what french lavender needs — so on a typical Wyoming parcel this is a transplant-or-protect crop, not a direct-sow one.

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"). French Lavender's 180-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

French Lavender draws honeybees, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, french lavender 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.

Good to Know Before You Plant French Lavender

French Lavender is listed as toxic to dogs, cats (all) at a mild level (ASPCA). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Worth knowing for placement: french lavender is woody and hardy only from zone 8, against a Wyoming low of zone 3, so it is overwintered under cover here rather than left standing outside — which is where it will be in reach.

Recommended French Lavender Varieties for Wyoming

Wyoming publishes no state variety trial for french lavender, so we won't invent a "best for Wyoming" list. Choose types rated to your USDA hardiness zone (3b-6a), and confirm winter survival and drainage against your own parcel.

Wyoming Cooperative Extension

For Wyoming-specific cultivar recommendations, planting calendars, and pest pressure for french lavender, the canonical source is University of Wyoming Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is French Lavender native to Wyoming?

No — the USDA PLANTS Database lists French Lavender 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 USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing French Lavender in Wyoming

When can I plant French Lavender 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). French Lavender overwinters only from USDA zone 8 and warmer, and Wyoming runs as cold as zone 3, so it does not survive winter in the ground here — the question for Wyoming growers is how to carry it through winter under cover, not which week to plant it.

What hardiness zone is French Lavender grown in across Wyoming?

Wyoming spans USDA hardiness zones 3b-6a (USDA ARS PHZM 2023). French Lavender carries a range of zones 8-9, 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). French Lavender needs 180+ 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 French Lavender native to Wyoming?

No — the USDA PLANTS Database lists French Lavender 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 French Lavender in Wyoming?

French Lavender prefers pH 5.8-8.3 and well (dry spells), excessive (dry/moderately dry) drainage (FAO ECOCROP). That sits in the common-ground band across Wyoming soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will French Lavender actually grow on my specific land in Wyoming?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores french lavender 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 Wyoming

State-level data is a sketch. Your Growable Ground report scores french lavender against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Wyoming french lavender averages can't show:

Your soil pHYour frost-free days — Wyoming averages 151Your sun & shade

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 french lavender 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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