Unlikely — Zone Mismatch
French lavender (zones 8-9) does not overlap with Colorado's zone range (3b-7b). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
French Lavender is hardy to zone 8, and the warmest ground in Colorado is zone 7 — 1 zone short. Planted in open ground it will not survive a Colorado winter. To grow it here, grow french lavender in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 8-9 (plant) against 3-7 (Colorado). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
French Lavender in Colorado — the short answer
French Lavender in Colorado: hardy in zones 8–9, full sun.
- Plant zones
- 8-9
- NC State Extension Gardener Plant Toolbox
- Colorado zones
- 3b-7b
- USDA PHZM 2023
- Frost window
- Apr 25 - May 19 – Sep 29 - Oct 16
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 85 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.
Your yard isn't the whole zone.
Colorado spans zones 3b-7b, 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 parcel report in seconds — read in full free for your first 14 days
Colorado is not one climate
Colorado’s winter-low ladder runs across 64 counties, from zone 4.5 in Alamosa County to zone 7 in Mesa County. That is 25°F between the two counties’ average coldest night — the difference between french lavender overwintering in the ground and coming under cover.
The middle half of 64 counties runs 5.5–6 zones, with a median of 5.5 zones — a 2.5-zone span end to end.
Measured across 64 Colorado 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 Colorado
French Lavender is rated for zones 8–9 — a cold floor USDA puts at 10 to 20°F. No Colorado 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 Colorado winters, not about french lavender.
Below the zone 8 floor
64 counties
- Alamosa County · zone 4b
- Jackson County · zone 4b
- Park County · zone 4b
3 of 64 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
- Sun: Full Sun
- Mature size: 2 ft tall
- Picking window: ~30 days of harvestWe haven't confirmed this against a published source yet.
- Drought tolerance: HighWe haven't confirmed this against a published source yet.
Colorado Has
- USDA Zones: 3b-7b
- Last Hard Freeze (28°F): Apr 25 - May 19
- First Hard Freeze (28°F): Sep 29 - Oct 16
- Annual Rainfall: 7-20 inches
- Common Soils: Sandy loam, Clay loam, Alkaline caliche
Plant Zone Range (zones 8-9)
Preferred Soil pH
We haven't confirmed this against a published source yet.
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 Colorado
The frost window
Across Colorado, the last spring hard freeze (28°F) clears between Apr 25 and May 19, and the first fall hard freeze lands between Sep 29 and Oct 16 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 133-day window you can count on — up to 174 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 Colorado's late-side last freeze of May 19 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), and Colorado 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 Colorado — 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 — Chaffee 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 Colorado 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 Colorado under protection.
Growing degree days
French Lavender needs ~1200 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~2083 GDD (from PRISM 1991-2020 climate normals), so Colorado'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 Colorado's sandy 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 Colorado soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells), excessive (dry/moderately dry). If your Colorado site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost. pH range, preferred pH and drainage need: We haven't confirmed this against a published source yet.
Your land, not the state average
Colorado'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. Colorado 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 Colorado’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 Colorado — and how to grow with it.
We checked the federal record across Colorado — 18,818 documented sites across 7 of the 8 source types we track.
The most significant on record: 281 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Colorado 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 of imported, lab-tested soil grow well almost anywhere in the meantime.
Sources Checked
across Colorado
Severity Distribution
across Colorado
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Colorado, Mining runs higher than the national average — 5,049 sites across Colorado. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Sources: EPA, USGS — 950K documented sites tracked nationwide across 8 federal source types.
What Else to Consider for French Lavender in Colorado
Zone compatibility tells you about winter cold survival — but Colorado growers also need to think about:
Low annual rainfall (7-20 inches) means irrigation is essential nearly everywhere
High altitude UV and temperature swings stress plants
Very short growing season at elevation (60-90 frost-free days above 8,000 ft)
Alkaline soils (pH 7.5-8.5) limit acid-loving plants without amendment
Growing french lavender here specifically
French Lavender wants pH 5.8–8.3 and rates to USDA zones 8–9, but Colorado's soils are dominantly loam — the fit is decided by your parcel's own map unit, not the state average.
Match french lavender to your parcel's SSURGO map unit — test pH and texture, and amend toward its 5.8–8.3 range. How to handle it →
What to actually do about these — and the constraints that apply to every Colorado grower, not just french lavender — is covered on the Colorado growing guide.
Timing shifts within Colorado
Colorado isn't one climate. In Chaffee County, the last hard freeze (28°F) holds until about Jun 12 — roughly 38 days later than the recorded state median — so plant french lavender 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 Colorado French Lavender Is Zone-Hardy
French Lavender is rated for USDA zones 8–9. No Colorado county reaches it. Even Mesa County, the state’s mildest winter at zone 7a, sits below the plant’s zone 8 floor — so in open ground this one needs winter protection here, or a container that comes under cover.
Across those 64 counties Colorado’s winter-low ladder runs from zone 4b in Alamosa County to zone 7a in Mesa County — 2.5 USDA zones of spread, which is 25°F between the two counties’ average coldest night of the year. None of that range reaches the band french lavender needs, so here the statewide answer really is the answer.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. French Lavender’s zone 8–9 band: NC State Extension Gardener Plant Toolbox. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
French Lavender draws honeybees, native bees, and butterflies (high value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, french lavender can only work that bloom inside Colorado's frost window — roughly 155 days, opening after the last 28°F freeze (Apr 25 - May 19) and closing at the first (Sep 29 - Oct 16), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.
Good to Know Before You Plant French Lavender
French Lavender is listed as toxic to dogs, cats (all) at a mild level. We haven't confirmed this against a published source yet. 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 Colorado 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 Colorado
Colorado publishes no state variety trial for french lavender, so we won't invent a "best for Colorado" list. Choose types rated to your USDA hardiness zone (3b-7b), and confirm winter survival and drainage against your own parcel.
Colorado Cooperative Extension
For Colorado-specific cultivar recommendations, planting calendars, and pest pressure for french lavender, the canonical source is Colorado State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is French Lavender native to Colorado?
No — the USDA PLANTS Database lists French Lavender as introduced rather than native in the Lower 48, so it is not part of Colorado's native flora. It grows here as a garden plant; pairing it with a few Colorado natives keeps local pollinators fed too.
Looking for plants that belong here? The Colorado growing guide lists plants that USDA PLANTS records growing in Colorado 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 French Lavender in Colorado
When can I plant French Lavender in Colorado?
Colorado's last spring hard freeze (28°F) clears between Apr 25 and May 19, and the first fall hard freeze lands between Sep 29 and Oct 16 (NOAA Regional Climate Centers ACIS, 1991-2020). French Lavender overwinters only from USDA zone 8 and warmer, and Colorado runs as cold as zone 3, so it does not survive winter in the ground here — the question for Colorado 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 Colorado?
Colorado spans USDA hardiness zones 3b-7b (USDA ARS PHZM 2023). French Lavender is listed for zones 8-9, which do not overlap them, so there is no zone in Colorado where this page can call outdoor growing reliable. A parcel report resolves your own address's zone.
How many frost-free days does a typical Colorado site have?
A typical Colorado site sees ~155 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 Chaffee, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is French Lavender native to Colorado?
No — the USDA PLANTS Database lists French Lavender as introduced rather than native in the Lower 48, so it is not part of Colorado's native flora. It grows here as a garden plant; pairing it with a few Colorado natives keeps local pollinators fed too.
How should I amend the soil for French Lavender in Colorado?
French Lavender prefers pH 5.8-8.3 and well (dry spells), excessive (dry/moderately dry) drainage. We haven't confirmed this against a published source yet. That sits in the common-ground band across Colorado 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 Colorado?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores french lavender 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 Colorado
State-level data is a sketch. Your Growable Ground report scores french lavender against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Colorado french lavender averages can't show:
We read public map data around Colorado — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Colorado french lavender average
Explore More
Growing guides for french lavender
Explore Colorado county by county
Colorado carries 64 counties with their own USDA zone — a sample of the growing pages for french lavender there:
Where else french lavender grows
French Lavender's zone band crosses state lines — these are the states closest to Colorado 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 Colorado
Colorado has a growing page for 886 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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