Gardening in Phoenix-Mesa-Chandler, AZ
This metro spans USDA zones 9a to 10a, so there is no single zone for Phoenix-Mesa-Chandler, AZ and anyone who gives you one is rounding. 68% of its ZIP codes are zone 9b; the rest are not.
Which zone you are in depends where you are
Phoenix-Mesa-Chandler, AZ covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 68% in zone 9b and wrong for the other 32%. Here is the actual split.
| Zone | ZIP codes | Share | |
|---|---|---|---|
| 9b | 111 | 68% | |
| 10a | 33 | 20% | |
| 9a | 20 | 12% |
Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.
Your freeze dates
No freeze range is shown for Phoenix-Mesa-Chandler, AZ, because the freeze window here crosses New Year, so an earliest-to-latest range would be arithmetic on dates that do not sit in order. The tools below still answer for individual ZIP codes here, and will say what applies.
Your growing season
NOAA publishes a growing-season length for each station, and across the 35 stations serving Phoenix-Mesa-Chandler, AZ it runs 222–365 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 93–108 °F , at or above the 90 °F point where cool-season crops bolt and tomato and pepper pollen fails — so midsummer sowings of lettuce and its relatives are worth holding here.
What survives the winter changes across Phoenix-Mesa-Chandler, AZ
Of 74 perennial fruits, nuts, berries, vegetables and herbs, 46 come through the winter in zone 9a and only 25 in zone 10a. That is a different garden at each end of the same metro.
| Zone | ZIPs | Survive | Fail for being too warm |
|---|---|---|---|
| 9a | 20 | 46 of 74 | 25 |
| 9b | 111 | 40 of 74 | 32 |
| 10a | 33 | 25 of 74 | 49 |
The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.
The 35 stations behind these numbers
Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.
| Station | NOAA ID | Last spring freeze | First fall freeze | Season |
|---|---|---|---|---|
| Aguila, AZ | USC00020060 | March 17 | November 19 | 243 days |
| Apache Junction 5 NE, AZ | USC00020288 | February 11 | December 10 | 304 days |
| Arizona City, AZ | USC00020404 | February 28 | November 21 | 266 days |
| Carefree, AZ | USC00021282 | February 4 | December 16 | 313 days |
| Casa Grande Nm, AZ | USC00021314 | February 17 | November 29 | 284 days |
| Casa Grande, AZ | USC00021306 | February 5 | December 6 | 305 days |
| Castle Hot Springs, AZ | USC00021353 | January 15 | December 22 | 341 days |
| Catalina SP, AZ | USC00021357 | April 2 | November 11 | 222 days |
| Chandler Heights, AZ | USC00021514 | February 1 | December 11 | 315 days |
| Dateland Whitewing Rch, AZ | USC00022434 | January 25 | December 13 | 324 days |
| E Mesa, AZ | USC00022782 | February 1 | December 10 | 312 days |
| Florence, AZ | USC00023027 | January 30 | December 12 | 319 days |
| Fountain Hills, AZ | USC00023190 | January 6 | December 28 | 356 days |
| Gila Bend 2Se, AZ | USC00023393 | January 23 | December 11 | 323 days |
| Laveen 3 Sse, AZ | USC00024829 | January 14 | December 22 | 343 days |
| Litchfield Park, AZ | USC00024977 | January 7 | December 24 | 351 days |
| Maricopa 4 N, AZ | USC00025270 | February 23 | November 24 | 274 days |
| Oracle SP, AZ | USC00026117 | March 29 | November 13 | 225 days |
| Painted Rock Dam, AZ | USC00026194 | January 21 | December 15 | 327 days |
| Phoenix Deer Valley Muni AP, AZ | USW00003184 | January 8 | December 25 | 354 days |
| Phoenix Sky Harbor INTL AP, AZ | USW00023183 | January 5 | January 3 | 365 days |
| Picacho 8 SE, AZ | USC00026513 | February 6 | December 9 | 308 days |
| Pinnacle Peak, AZ | USC00026603 | January 27 | December 21 | 330 days |
| Punkin Ctr, AZ | USC00026840 | March 7 | November 20 | 255 days |
| Roosevelt 1 S, AZ | USC00027281 | January 17 | December 25 | 342 days |
| San Carlos Reservoir, AZ | USC00027480 | March 13 | November 19 | 247 days |
| San Manuel, AZ | USC00027530 | February 4 | December 8 | 306 days |
| Scottsdale Muni AP, AZ | USW00003192 | January 6 | December 26 | 353 days |
| South Phoenix, AZ | USC00028112 | January 21 | December 16 | 331 days |
| Stewart Mtn Dam, AZ | USC00028214 | February 13 | December 5 | 295 days |
| Superior, AZ | USC00028348 | January 18 | December 28 | 342 days |
| Tempe Asu, AZ | USC00028499 | February 13 | December 5 | 298 days |
| Wickenburg, AZ | USC00029287 | March 7 | November 20 | 254 days |
| Wittmann 1Se, AZ | USC00029464 | February 5 | December 11 | 306 days |
| Youngtown, AZ | USC00029634 | January 20 | December 15 | 331 days |
These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.
Work out your own dates
Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.
- What survives my winter?
Runs on the hardiness zone, so it answers for all of Phoenix-Mesa-Chandler, AZ at once — zone across 74 perennial fruits, berries, vegetables and herbs.
- When do I start my seeds?
Dates every spring job from your own last freeze — sow indoors, set out, direct sow.
- When do I sow the next round?
How often each crop is worth re-sowing, and when the next sowing is due.
- What can I still plant?
Counts the growing days left before your first fall freeze, crop by crop.
Where these numbers come from
The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.
This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.