Unlikely — Zone Mismatch
French lavender (zones 8-9) does not overlap with Wisconsin'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 Wisconsin is zone 6 — 2 zones short. Planted in open ground it will not survive a Wisconsin winter. To grow it here, grow french lavender under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 8-9 (plant) against 3-6 (Wisconsin). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
Wisconsin 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.
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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
Wisconsin Has
- USDA Zones: 3b-6a
- Last Hard Freeze (28°F): Apr 17 - May 2
- First Hard Freeze (28°F): Oct 9 - Oct 21
- Annual Rainfall: 28-34 inches
- Common Soils: Silt loam, Clay loam, Sandy outwash
Plant Zone Range (zones 8-9)
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 French Lavender in Wisconsin
The frost window
Across Wisconsin, the last spring hard freeze (28°F) clears between Apr 17 and May 2, and the first fall hard freeze lands between Oct 9 and Oct 21 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 160-day window you can count on — up to 187 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 Wisconsin's late-side last freeze of May 2 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 Wisconsin 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 Wisconsin — 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 — Florence 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 french lavender does not survive a Wisconsin 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 Wisconsin under protection.
Frost-free days
French Lavender wants 180+ frost-free days; a typical Wisconsin site sees ~173 (NOAA Regional Climate Centers ACIS, 1991-2020) — 7 days short of what it needs. A typical Wisconsin 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 ~2102 GDD (from PRISM 1991-2020 climate normals), so Wisconsin'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 Wisconsin'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 6.5 and 7.5 — worth knowing before you decide whether a Wisconsin soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells), excessive (dry/moderately dry). If your Wisconsin site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
SSURGO maps about 19.9% of Wisconsin as poorly or somewhat-poorly drained, and the class flips parcel to parcel. French Lavender tolerates drought well, so wet feet — not dry spells — is its real risk here — your soil map unit, not the state average, is the real answer.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Wisconsin soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
French Lavender in Wisconsin — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 8-9 (USDA PLANTS Database)
- State Zones: 3b-6a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Apr 17 - May 2 to Oct 9 - Oct 21 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 90 days
What Else to Consider for French Lavender in Wisconsin
Zone compatibility tells you about winter cold survival — but Wisconsin growers also need to think about:
Cold winters (-30F in northern WI)
Short growing season (110-140 frost-free days)
Sandy central soils drain too quickly
Growing french lavender here specifically
French Lavender likes pH 5.8–8.3 and takes cold to about 44°F, yet neither saves it from wet feet — SSURGO maps about 19.9% of Wisconsin poorly-drained, where its crown sit and rot.
Set french lavender high on bermed, grit-amended ground so winter and storm water drain away from the crown. How to handle it →
What to actually do about these — and the constraints that apply to every Wisconsin grower, not just french lavender — is covered on the Wisconsin growing guide.
Timing shifts within Wisconsin
Wisconsin isn't one climate. In Florence County, the last hard freeze (28°F) holds until about May 16 — roughly 21 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. 28 of Wisconsin’s 72 counties give it that outright. The tightest that does is Green Lake County at 180 frost-free days — 0 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Wisconsin’s 72 counties the frost-free season runs from 140 days in Florence County to 217 days in Milwaukee County — a spread of 77 days, which is why a single statewide planting date misleads. The median Wisconsin county sees 173 frost-free days, which is 7 days short of what french lavender needs — so on a typical Wisconsin 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 Wisconsin's frost window — roughly 173 days, opening after the last 28°F freeze (Apr 17 - May 2) and closing at the first (Oct 9 - Oct 21), 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 Wisconsin 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 Wisconsin
Wisconsin publishes no state variety trial for french lavender, so we won't invent a "best for Wisconsin" list. Choose types rated to your USDA hardiness zone (3b-6a), and confirm winter survival and drainage against your own parcel.
Wisconsin Cooperative Extension
For Wisconsin-specific cultivar recommendations, planting calendars, and pest pressure for french lavender, the canonical source is UW–Madison Division of Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is French Lavender native to Wisconsin?
No — the USDA PLANTS Database lists French Lavender as introduced rather than native in the Lower 48, so it is not part of Wisconsin's native flora. It grows here as a garden plant; pairing it with a few Wisconsin natives keeps local pollinators fed too.
Looking for plants that belong here? The Wisconsin 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 Wisconsin
When can I plant French Lavender in Wisconsin?
Wisconsin's last spring hard freeze (28°F) clears between Apr 17 and May 2, and the first fall hard freeze lands between Oct 9 and Oct 21 (NOAA Regional Climate Centers ACIS, 1991-2020). French Lavender overwinters only from USDA zone 8 and warmer, and Wisconsin runs as cold as zone 3, so it does not survive winter in the ground here — the question for Wisconsin 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 Wisconsin?
Wisconsin 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 Wisconsin site have?
A typical Wisconsin site sees ~173 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 Florence, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is French Lavender native to Wisconsin?
No — the USDA PLANTS Database lists French Lavender as introduced rather than native in the Lower 48, so it is not part of Wisconsin's native flora. It grows here as a garden plant; pairing it with a few Wisconsin natives keeps local pollinators fed too.
How should I amend the soil for French Lavender in Wisconsin?
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 Wisconsin 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 Wisconsin?
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.
Check your specific parcel in Wisconsin
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 Wisconsin french lavender averages can't show:
We read public map data around Wisconsin — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wisconsin french lavender average
Explore More
Growing guides for french lavender
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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