Generally — Most Areas
sourwood (zones 6-12) partially overlaps with Arizona (4b-10b). It can grow in zones 6-10 within the state.
Your yard isn't the whole zone.
Arizona spans zones 4b-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 sourwood against your parcel's actual hardiness, soil, and sun.
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Zone Comparison
Sourwood Needs
- USDA Zones: 6-12
- Soil pH: 4 - 6.5
- Sun: Shade
- Frost-Free Days: 150+
Arizona Has
- USDA Zones: 4b-10b
- Last Frost: Jan 15 - May 1
- First Frost: Oct 15 - Dec 15
- Annual Rainfall: 3-25 inches
- Common Soils: Caliche, Sandy loam, Desert pavement
Plant Zone Range (zones 6-12)
Preferred Soil pH
Plant data: USDA PLANTS Database / plant_species_v5.csv. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Sourwood in Arizona
The frost window
Across Arizona, the last spring frost clears between Jan 15 and May 1, and the first fall frost lands between Oct 15 and Dec 15 (NOAA Climate Normals 1991-2020). Counting from the latest last frost to the earliest first frost, that's a 167-day window you can count on — up to 334 days on a mild site in a kind year.
Frost hardiness
Sourwood is cold-hardy to -13°F (USDA PLANTS Database), so you can plant on the early side of Arizona's window — even a few weeks before the final frost date.
Establishment timing
As a long-lived plant, sourwood isn't racing the calendar to a harvest date. Plant it in spring once the last-frost window passes so roots settle in through the full season, or in early fall while the soil still holds summer warmth.
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
Zone compatibility says you can survive winter here. Whether the growing season is long enough — and warm enough — is a different question.
Frost-free days
Sourwood wants 150+ frost-free days; a typical Arizona site sees ~220 (NOAA Climate Normals). That leaves comfortable headroom for succession planting.
Chill hours
Sourwood requires ~600 chill hours (32-45°F dormancy window). Arizona typically banks ~900 chill hours per winter (MSU Extension method), which keeps this plant on track.
Climate aggregates derive from USDA NRCS county-level hardiness data + Cornell CALS Extension GDD-by-region tables + MSU Extension chill-hours-by-zone (1991-2020 NOAA Climate Normals baseline).
Soil + Drainage Fit
Sourwood likes near-neutral soil (pH 4-6.5). That's the common-ground band across Arizona's caliche and sandy loam — a soil test confirms it for your site.
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.
Sourwood in Arizona — Quick Answer
- Verdict: Generally — Most Areas
- Plant Zones: 6-12 (USDA PLANTS Database)
- State Zones: 4b-10b (USDA ARS PHZM 2023)
- Growing Season: Jan 15 - May 1 to Oct 15 - Dec 15 (NOAA Climate Normals)
What Else to Consider
Zone compatibility tells you about winter cold survival — but Arizona growers also need to think about:
Extreme heat exceeding 110F stresses most plants
Desert gardens run on winter: plant to the October-March windows and give the summer holdouts afternoon shade.
Minimal rainfall requires drip irrigation
Drip plus a deep mulch layer is the desert baseline — it waters roots, not air, and cuts evaporation dramatically.
Caliche hardpan prevents root penetration without breaking through
Where caliche won't break, build up instead — a deep raised bed gives roots the depth the ground refuses.
Pollinator + Wildlife Value
Sourwood draws pollinators (high value, USDA PLANTS Database). Planting it near vegetable beds can lift fruit set on neighboring crops.
Arizona Cooperative Extension
For Arizona-specific cultivar recommendations, planting calendars, and pest pressure for sourwood, 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 Sourwood native to Arizona?
Sourwood 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 Sourwood in Arizona
When can I plant Sourwood in Arizona?
Arizona's last spring frost clears between Jan 15 and May 1, and the first fall frost lands between Oct 15 and Dec 15 (NOAA Climate Normals 1991-2020). Sourwood is a long-lived planting, so target spring just after your local last frost — or early fall while the soil holds warmth — and let it establish through the season.
What hardiness zone is Sourwood grown in across Arizona?
Arizona spans USDA hardiness zones 4b-10b (USDA ARS PHZM 2023). Sourwood carries a range of zones 6-12, 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 ~220 frost-free days per year (derived from NOAA Climate Normals 1991-2020). Sourwood needs 150+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Sourwood native to Arizona?
Sourwood 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 Sourwood in Arizona?
Sourwood prefers pH 4-6.5 (USDA PLANTS 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 Sourwood actually grow on my specific land in Arizona?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores sourwood 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 sourwood against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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