Three Points, Arizona, sits in USDA hardiness zone 9a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Growers here do well with artichoke, fig, california poppy, and cabbage — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Three Points, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Three Points lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Three Points — soil, climate, flood, and parcel records. How we handle your address.
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Three Points — the short answer
Three Points, Arizona: USDA zone 9a, about 313 days between hard freezes, across 30K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 3
- Pima County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 13
- Pima County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~313
- Pima County normal — NOAA 1991–2020, nearest to this town
- Town area
- 30K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Pima County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Three Points's average, not your lot's — a low corner or a tree line moves it. Against Three Points's 313-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Three Points
Each reading below is measured for Three Points itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsThree Points runs about 313 days between hard freezes (read from Pima County, the closest normal to Three Points) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredThree Points sits in USDA hardiness zone 9a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Three Points is in
Three Points sits in the Sonoran Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at Three Points's own centroid rather than borrowed from Pima County.
What Grows in Three Points
Every plant below cleared Three Points's own zone 9a and its 313-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in Three Points?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 6; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 13 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What's on the federal record near Three Points
Closest first, within ~10 miles of Three Points. Listing isn't leaking, and distance isn't exposure.
- SPEEDWAY STORE #2959Underground Storage Tanks · 1.6 mi
- KJ'S CONVENIENT STOPUnderground Storage Tanks · 1.9 mi
- THREE POINTS GENERAL STOREUnderground Storage Tanks · 1.9 mi
- ADOT - 3 POINTS MAINTENANCEUnderground Storage Tanks · 2.1 mi
- ALTAR VALLEY MIDDLE SCHOOLUnderground Storage Tanks · 2.1 mi
- D-16-10 24BCBNitrate · 2.2 mi
- D-16-11 08BDBNitrate · 2.4 mi
- D-16-10 04BDA1Nitrate · 2.5 mi
- DUVAL PENNZOIL FARMUnderground Storage Tanks · 2.5 mi
- D-15-10 33DBC1Nitrate · 2.7 mi
- D-15-10 28CDCNitrate · 3.3 mi
- D-16-11 09ACANitrate · 3.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Three Points's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Three Points.
Sources Checked
within ~10 miles of Three Points
Severity Distribution
within ~10 miles of Three Points
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Three Points, two things run higher than the national average within ~10 miles of Three Points — Mining (23 sites) and Nitrate (64 sites). 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.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Three Points
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Three Points average
Your land is one point inside Three Points
Everything above resolves to Three Points as a whole — one PHZM band, read across 30K acres, with hard-freeze dates borrowed from Pima County’s record because no 30-year normal resolves at this town’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Three Points Average
Three Points Average
- ●USDA Zones 9a, averaged across Three Points
- ●One soil character for all of Three Points
- ●Frost dates read at Three Points's scale: Feb 3 to Dec 13
YOUR Parcel
- ✓Your exact zone, not Three Points's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Three Points
Pull a site-specific report for your exact address in Three Points, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Three Points averages can't show:
We read public map data around Three Points — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Three Points average
How we know this about Three Points
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Pima County’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Three Points
When does frost risk typically end in Three Points?
The last hard freeze (28°F) in Three Points typically lands around Feb 3, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Feb 24.
When is the first frost in Three Points?
The first hard freeze (28°F) in Three Points typically arrives around Dec 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 29, so the watching starts about Nov 13 — about 313 days after the spring freeze cleared.
How long is the growing season in Three Points?
Measured between 28°F hard freezes, Three Points sees about 313 frost-free days — roughly Feb 3 through Dec 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 24 to Nov 29, about 278 days.
Is the soil safe to grow vegetables in Three Points?
The federal record around Three Points is a meaningful one — 95 documented sites, mostly Nitrate entries (64), the nearest Underground Storage Tanks record about 1.6 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Three Points?
From about Nov 13 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Dec 13 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Dec 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Three Points's scale — its 9a band and its 313-day season. Your yard writes its own version of Three Points's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Three Points’s own scale
5 of the readings below were taken at Three Points's own scale — the 29,834 acres it covers and 95 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Three Points's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 95 documented contamination sites on the federal record near Three Points, the closest Underground Storage Tanks record about 1.6 miles out from the town centreFederal environmental registers
- Three Points's boundary and the 29,834 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~313-day seasonGrowable Ground crop-matching engine
- The ecoregion at Three Points's own centroid, the Sonoran Basin and RangeUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Three Points has no normal of its own, so its county's is the closest measured readfrom Pima County
- Soil character — no town-scale survey exists, so Three Points's 29,834 acres read through its county's SSURGO summaryfrom Pima County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Pima County
- The growing challenges every Arizona grower plans around — written at state scale, so they stay on the state guidefrom Arizona
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Pima County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Three Points's 29,834 acreswhy one lot differs from the next →
- Which side of Three Points you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 29,834 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 1.6 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Three Points-wide figureread your own land →