Generally — Most Areas
saffron crocus (zones 6-9) suits most of Arizona (5b-10b) — zones 6-9 are in range, and the rest of the state is the exception.
Saffron Crocus in Arizona — the short answer
Saffron Crocus in Arizona: hardy in zones 6–9, full sun.
- Plant zones
- 6-9
- Not verified — NC State Extension Gardener Plant Toolbox lists zones 5a–8b
- Arizona zones
- 5b-10b
- USDA PHZM 2023
- Frost window
- Feb 1 - Apr 2 – Nov 13 - Dec 12
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 150 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 75 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.
Arizona spans zones 5b-10b, 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 saffron crocus 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
Arizona is not one climate
Arizona’s winter-low ladder runs across 15 counties, from zone 6 in Coconino County to zone 9.5 in Yuma County. That is 35°F between the two counties’ average coldest night — the difference between saffron crocus overwintering in the ground and coming under cover.
The middle half of 15 counties runs 7.5–9.5 zones, with a median of 8.5 zones — a 3.5-zone span end to end.
Measured across 15 Arizona 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 in Arizona Fits Best
Saffron Crocus is rated for zones 6–9 — a cold floor USDA puts at -10 to 0°F. Against Arizona’s 15 counties that band holds in 11 of them, and the line runs at Coconino County (zone 6a), the coldest county still inside it.
Inside zones 6–9
11 counties
- Apache County · zone 6b
- Navajo County · zone 7a
- Yavapai County · zone 7b
3 of 11 shown
Above the zone 9 ceiling
4 counties
- La Paz County · zone 9b
- Maricopa County · zone 9b
- Pinal County · zone 9b
3 of 4 shown
Warmer than the zone 9 end of its range.
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.
Even within Arizona's zones 5b-10b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for saffron crocus (USDA PHZM 2023):
Zone Comparison
Saffron Crocus Needs
- USDA Zones: 6-9
- Sun: Full Sun
- Mature size: 6 in tallWe haven't confirmed this against a published source yet.
- Picking window: ~7 days of harvestWe haven't confirmed this against a published source yet.
- Drought tolerance: HighWe haven't confirmed this against a published source yet.
Arizona Has
- USDA Zones: 5b-10b
- Last Hard Freeze (28°F): Feb 1 - Apr 2
- First Hard Freeze (28°F): Nov 13 - Dec 12
- Annual Rainfall: 3-25 inches
- Common Soils: Caliche, Sandy loam, Desert pavement
Plant Zone Range (zones 6-9)
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 Saffron Crocus in Arizona
The frost window
Across Arizona, the last spring hard freeze (28°F) clears between Feb 1 and Apr 2, and the first fall hard freeze lands between Nov 13 and Dec 12 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 225-day window you can count on — up to 314 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.
Winter standing
Arizona runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for saffron crocus, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether saffron crocus is a permanent planting or a replant-every-spring crop for you turns on your own zone within Arizona; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Coconino 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 saffron crocus survives winter in part of Arizona, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Growing degree days
Saffron Crocus needs ~1500 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~3945 GDD (from PRISM 1991-2020 climate normals), so Arizona'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
Saffron Crocus 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 Arizona. 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 8 — worth knowing before you decide whether a Arizona soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Arizona 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
Arizona's soils run mostly sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for saffron crocus is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how saffron crocus 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. Arizona soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant saffron crocus 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 saffron crocus goes in. What follows is Arizona’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 Arizona — and how to grow with it.
We checked the federal record across Arizona — 18,099 documented sites across 6 of the 8 source types we track.
The most significant on record: 184 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Arizona 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 Arizona
Severity Distribution
across Arizona
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Arizona, Mining runs higher than the national average — 6,160 sites across Arizona. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Saffron Crocus in Arizona
Zone compatibility tells you about winter cold survival — but Arizona growers also need to think about:
Extreme heat exceeding 110F stresses most plants
Minimal rainfall requires drip irrigation
Caliche hardpan prevents root penetration without breaking through
Growing saffron crocus here specifically
Arizona's soils run mostly sandy loam (Aridisols), and whether that suits saffron crocus's pH 5.5–8.5 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward saffron crocus's 5.5–8.5 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Arizona grower, not just saffron crocus — is covered on the Arizona growing guide.
Timing shifts within Arizona
Arizona isn't one climate. In Coconino County, the last hard freeze (28°F) holds until about May 15 — roughly 78 days later than the recorded state median — so plant saffron crocus 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 Arizona Saffron Crocus Is Zone-Hardy
Saffron Crocus is rated for USDA zones 6–9. 11 of Arizona’s 15 counties fall inside that band. The coldest that does is Coconino County at zone 6a. 4 counties sit above its zone 9 ceiling, where the limit is too little winter chill rather than too much cold. Where you are in Arizona decides this one.
Across those 15 counties Arizona’s winter-low ladder runs from zone 6a in Coconino County to zone 9b in Yuma County — 3.5 USDA zones of spread, which is 35°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. Coconino County holds its last hard freeze (28°F) until about May 15, while Maricopa County is clear by Jan 15 — 120 days apart. Set saffron crocus 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". Saffron Crocus’s zone 6–9 band: Not verified — NC State Extension Gardener Plant Toolbox lists zones 5a–8b. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Saffron Crocus draws honeybees and native bees (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, saffron crocus can only work that bloom inside Arizona's frost window — roughly 266 days, opening after the last 28°F freeze (Feb 1 - Apr 2) and closing at the first (Nov 13 - Dec 12), 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 Saffron Crocus
Saffron Crocus is listed as toxic to dogs, cats. (Source: Pet Poison Helpline.) Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
On Growable Ground, Saffron Crocus means Crocus sativus — not to be confused with autumn crocus (Colchicum autumnale). a different plant that is very toxic to pets; if you cannot tell which one a pet ate, treat it as autumn crocus.
Recommended Saffron Crocus Varieties for Arizona
Arizona publishes no state variety trial for saffron crocus, so we won't invent a "best for Arizona" list. Choose types rated to your USDA hardiness zone (5b-10b), and confirm winter survival and drainage against your own parcel.
Arizona Cooperative Extension
For Arizona-specific cultivar recommendations, planting calendars, and pest pressure for saffron crocus, the canonical source is University of Arizona Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Saffron Crocus native to Arizona?
No — the USDA PLANTS Database lists Saffron Crocus as introduced rather than native in the Lower 48, so it is not part of Arizona's native flora. It grows here as a garden plant; pairing it with a few Arizona natives keeps local pollinators fed too.
Looking for plants that belong here? The Arizona growing guide lists plants that USDA PLANTS records growing in Arizona 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 Saffron Crocus in Arizona
When can I plant Saffron Crocus in Arizona?
Arizona's last spring hard freeze (28°F) clears between Feb 1 and Apr 2, and the first fall hard freeze lands between Nov 13 and Dec 12 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Saffron Crocus, so this page does not state whether it overwinters in Arizona 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 Saffron Crocus grown in across Arizona?
Arizona spans USDA hardiness zones 5b-10b (USDA ARS PHZM 2023). Saffron Crocus carries a range of zones 6-9, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Arizona site have?
A typical Arizona site sees ~266 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Saffron Crocus needs 150+ 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 Coconino, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Saffron Crocus native to Arizona?
No — the USDA PLANTS Database lists Saffron Crocus as introduced rather than native in the Lower 48, so it is not part of Arizona's native flora. It grows here as a garden plant; pairing it with a few Arizona natives keeps local pollinators fed too.
How should I amend the soil for Saffron Crocus in Arizona?
Saffron Crocus tolerates pH 5.5-8.5 and well (dry spells) drainage. We haven't confirmed this against a published source yet. That is a 3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Arizona site — amend for drainage and organic matter first.
Will Saffron Crocus actually grow on my specific land in Arizona?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores saffron crocus 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 Arizona
State-level data is a sketch. Your Growable Ground report scores saffron crocus against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Arizona saffron crocus averages can't show:
We read public map data around Arizona — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Arizona saffron crocus average
Explore More
Growing guides for saffron crocus
Explore Arizona county by county
Arizona carries 15 counties with their own USDA zone — a sample of the growing pages for saffron crocus there:
Where else saffron crocus grows
Saffron Crocus's zone band crosses state lines — these are the states closest to Arizona 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 Arizona
Arizona has a growing page for 1,036 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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