Conditional — Some Areas
firebush (zones 9-10) reaches only part of Arizona (5b-10b): zones 9-10 are in range, so where you are in the state decides it.
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 firebush 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
Zone Comparison
Firebush Needs
- USDA Zones: 9-10
- Frost-Free Days: 300+
- Sun: Full Sun
- Mature size: 15 ft tall
- Drought tolerance: Medium
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 9-10)
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 Firebush 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 firebush, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether firebush 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.
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 firebush survives winter in part of Arizona, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Firebush wants 300+ frost-free days; a typical Arizona site sees ~266 (NOAA Regional Climate Centers ACIS, 1991-2020) — 34 days short of what it needs. A typical Arizona 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.
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
Firebush likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across Arizona's caliche and sandy loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 7 — 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, raised beds or amendment with compost solve it.
Plant pH and drainage requirements from USDA PLANTS Database. Arizona soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Firebush in Arizona — Quick Answer
- Verdict: Conditional — Some Areas
- Plant Zones: 9-10 (USDA PLANTS Database)
- State Zones: 5b-10b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Feb 1 - Apr 2 to Nov 13 - Dec 12 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Firebush 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
What to actually do about these — and the constraints that apply to every Arizona grower, not just firebush — is covered on the Arizona growing guide.
Timing shifts within Arizona
Firebush needs about 300 days of frost-free season to complete its cycle. 5 of Arizona’s 15 counties give it that outright. The tightest that does is Pima County at 313 frost-free days — 13 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Arizona’s 15 counties the frost-free season runs from 150 days in Coconino County to 345 days in Maricopa County — a spread of 195 days, which is why a single statewide planting date misleads. The median Arizona county sees 266 frost-free days, which is 34 days short of what firebush needs — so on a typical Arizona 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"). Firebush's 300-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Where in Arizona Fits Best
Even within Arizona's zones 5b-10b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for firebush (USDA PHZM 2023):
Pollinator + Wildlife Value
Firebush draws honeybees, native bees, butterflies, and hummingbirds (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, firebush 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.
Arizona Cooperative Extension
For Arizona-specific cultivar recommendations, planting calendars, and pest pressure for firebush, 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 Firebush native to Arizona?
Firebush is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Arizona. It can still earn a place in a Arizona garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Arizona 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 Firebush in Arizona
When can I plant Firebush 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 Firebush, 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 Firebush grown in across Arizona?
Arizona spans USDA hardiness zones 5b-10b (USDA ARS PHZM 2023). Firebush carries a range of zones 9-10, 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). Firebush needs 300+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Firebush native to Arizona?
Firebush is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Arizona. It can still earn a place in a Arizona garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for Firebush in Arizona?
Firebush prefers pH 5.5-7.5 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across Arizona soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Firebush actually grow on my specific land in Arizona?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores firebush 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 Arizona
State-level data is a sketch. Your Growable Ground report scores firebush against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Arizona firebush 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 firebush average
Explore More
Growing guides for firebush
Last updated: