Place guide
Planting zones in Santa Rosa-Petaluma, CA
This metro spans USDA zones 9a to 10a, so there is no single zone for Santa Rosa-Petaluma, CA and anyone who gives you one is rounding. 61% of its ZIP codes are zone 9b; the rest are not.
Your ZIP code
Get the exact answer for your address
Everything above describes Santa Rosa-Petaluma, CA as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact — enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.
Santa Rosa-Petaluma, CA does not have one planting answer
Its own weather stations disagree about 27 of the 32 crops in this table right now, so any single list would be wrong for part of the metro area. That is not a gap in the data — it is what the data says.
- Shortest season
- 240 days
GRATON, CA US (USC00043578) - Longest season
- 365 days
BODEGA 6 WSW, CA US (USW00093245)
125 days of growing season separate those two stations, and both serve ZIP codes in Santa Rosa-Petaluma, CA. The ZIP lookup above answers for one address instead of averaging a place that has no average.
Why the hardiness zone does not settle this
A USDA zone is a winter-minimum statistic. It was never a growing-season one, and it does not behave like one: within a single zone the growing season runs a median 54 days wider at the 10th–90th percentile, and annual growing degree days vary by 2.02×.
The zones also overlap rather than stack — 30% of zone 6b freezes before the median zone 6a station. The zone tells you what survives your winter; the station tells you what finishes before your autumn.
All 12 stations agreeAt least one station
Every one of the 12 NOAA stations serving this metro area counts March 20 – November 13 as growing season (238 days). Widening to any single station gives January 1 – December 31 (364 days).
That is a 126-day difference inside one metro area — which is why this page gives ranges rather than a single planting date. The ZIP lookup above resolves it to one station.
Which zone you are in depends where you are
Santa Rosa-Petaluma, CA 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 61% in zone 9b and wrong for the other 39%. Here is the actual split.
| Zone | ZIP codes | Share | |
|---|---|---|---|
| 9b | 23 | 61% | |
| 9a | 10 | 26% | |
| 10a | 5 | 13% |
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
Those are the earliest and latest medians among the 12 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.
The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.
Your growing season
NOAA publishes a growing-season length for each station, and across the 12 stations serving Santa Rosa-Petaluma, CA it runs 240–365 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 62–92 °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. Summer rain over the same months runs 0.3–0.8" across those 12 stations, against the rough inch a week — about 13 inches over the same 92 days — that a vegetable garden is usually reckoned to want. The middle station covers about 3% of it, so a summer garden here is watered rather than rained on. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 83 °F summer afternoon drying the soil faster than a cool one.
When to start seeds in Santa Rosa-Petaluma, CA
Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 12 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.
| Crop | Job | When | Offset |
|---|---|---|---|
| Arugula | Direct sow | January 1 – December 4 | 4 weeks before |
| Baby Salad Greens | Direct sow | January 1 – December 4 | 4 weeks before |
| Beets | Direct sow | January 1 – December 4 | 4 weeks before |
| Green Onions | Start indoors | January 1 – December 31 | 8 weeks before |
| Green Onions | Direct sow | January 1 – December 4 | 4 weeks before |
| Mustard Greens | Direct sow | January 1 – December 4 | 4 weeks before |
| Okra | Start indoors | January 1 – December 4 | 4 weeks before |
| Peppers | Start indoors | January 1 – December 31 | 8 weeks before |
| Radishes | Direct sow | January 1 – December 4 | 4 weeks before |
| Turnips | Direct sow | January 1 – December 4 | 4 weeks before |
| Broccoli | Start indoors | January 4 – December 23 | 6 weeks before |
| Cabbage | Start indoors | January 4 – December 23 | 6 weeks before |
| Collards | Start indoors | January 4 – December 23 | 6 weeks before |
| Kale | Start indoors | January 4 – December 23 | 6 weeks before |
| Leaf Lettuce | Start indoors | January 4 – December 23 | 6 weeks before |
| Peas | Direct sow | January 4 – December 23 | 6 weeks before |
| Spinach | Direct sow | January 4 – December 23 | 6 weeks before |
| Sweet Potato | Start indoors | January 4 – December 23 | 6 weeks before |
| Tomatoes | Start indoors | January 4 – December 23 | 6 weeks before |
| Bush Beans | Direct sow | January 8 – March 27 | 1 week after |
| Cabbage | Set out | January 8 – December 11 | 3 weeks before |
| Carrots | Direct sow | January 8 – December 11 | 3 weeks before |
| Collards | Direct sow | January 8 – December 11 | 3 weeks before |
| Collards | Set out | January 8 – December 11 | 3 weeks before |
| Cucumbers | Set out | January 8 – March 27 | 1 week after |
| Cucumbers | Start indoors | January 8 – December 11 | 3 weeks before |
| Green Onions | Set out | January 8 – December 11 | 3 weeks before |
| Kale | Direct sow | January 8 – December 11 | 3 weeks before |
| Kale | Set out | January 8 – December 11 | 3 weeks before |
| Kohlrabi | Direct sow | January 8 – December 11 | 3 weeks before |
| Kohlrabi | Set out | January 8 – December 11 | 3 weeks before |
| Leaf Lettuce | Direct sow | January 8 – December 11 | 3 weeks before |
| Pumpkins | Direct sow | January 8 – March 27 | 1 week after |
| Pumpkins | Set out | January 8 – March 27 | 1 week after |
| Pumpkins | Start indoors | January 8 – December 11 | 3 weeks before |
| Summer Squash | Direct sow | January 8 – March 27 | 1 week after |
| Summer Squash | Set out | January 8 – March 27 | 1 week after |
| Summer Squash | Start indoors | January 8 – December 11 | 3 weeks before |
| Sweet Corn | Direct sow | January 8 – March 27 | 1 week after |
| Tomatoes | Set out | January 8 – March 27 | 1 week after |
| Winter Squash | Direct sow | January 8 – March 27 | 1 week after |
| Winter Squash | Set out | January 8 – March 27 | 1 week after |
| Winter Squash | Start indoors | January 8 – December 11 | 3 weeks before |
| Zucchini | Direct sow | January 8 – March 27 | 1 week after |
| Zucchini | Set out | January 8 – March 27 | 1 week after |
| Zucchini | Start indoors | January 8 – December 11 | 3 weeks before |
| Bok Choy | Start indoors | January 11 – December 30 | 5 weeks before |
| Kohlrabi | Start indoors | January 11 – December 30 | 5 weeks before |
| Swiss Chard | Start indoors | January 11 – December 30 | 5 weeks before |
| Bok Choy | Direct sow | January 15 – December 18 | 2 weeks before |
| Bok Choy | Set out | January 15 – December 18 | 2 weeks before |
| Broccoli | Set out | January 15 – December 18 | 2 weeks before |
| Cilantro | Direct sow | January 15 – December 18 | 2 weeks before |
| Cucumbers | Direct sow | January 15 – April 3 | 2 weeks after |
| Leaf Lettuce | Set out | January 15 – December 18 | 2 weeks before |
| Okra | Direct sow | January 15 – April 3 | 2 weeks after |
| Okra | Set out | January 15 – April 3 | 2 weeks after |
| Peppers | Set out | January 15 – April 3 | 2 weeks after |
| Southern Peas | Direct sow | January 15 – April 3 | 2 weeks after |
| Sweet Potato | Set out | January 15 – April 3 | 2 weeks after |
| Swiss Chard | Direct sow | January 15 – December 18 | 2 weeks before |
| Swiss Chard | Set out | January 15 – December 18 | 2 weeks before |
| Dill | Direct sow | January 22 – December 25 | 1 week before |
The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.
What survives the winter changes across Santa Rosa-Petaluma, CA
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 | 10 | 46 of 74 | 25 |
| 9b | 23 | 40 of 74 | 32 |
| 10a | 5 | 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.
At least one station here freezes across the new year, which puts the two ends of a spread on opposite sides of the calendar. Drawing it would produce a bar spanning almost the whole year and meaning nothing, so none is drawn.
The 12 stations behind these numbers
All 12 NOAA stations whose normals this page quotes, spanning about 59 km north to south. Every one is named with its identifier in the station list below — this page does not single one out, because no one station speaks for a whole metro area.
A relative sketch, not a map with a projection: longitude is adjusted for latitude so the shape is not stretched, and there is no basemap. For the one station nearest a specific address, with its real distance, use the ZIP lookup above.
Every figure above comes from these, and each is named so you can check it. Which station serves a given ZIP code, and how far away it is, varies across the metro — the table below gives it per ZIP code rather than this page averaging it.
| Station | NOAA ID | Last spring freeze | First fall freeze | Season |
|---|---|---|---|---|
| Bodega 6 Wsw, CA | USW00093245 | January 1 | December 31 | 365 days |
| Calistoga, CA | USC00041312 | March 2 | November 23 | 263 days |
| Cloverdale, CA | USC00041838 | February 25 | December 3 | 279 days |
| Ft Ross, CA | USC00043191 | February 26 | December 27 | 310 days |
| Graton, CA | USC00043578 | March 20 | November 13 | 240 days |
| Healdsburg, CA | USC00043875 | February 15 | December 2 | 292 days |
| Occidental, CA | USC00046370 | January 29 | December 30 | 347 days |
| Petaluma AP, CA | USC00046826 | February 28 | November 25 | 271 days |
| Saint Helena, CA | USC00047643 | February 3 | December 4 | 306 days |
| Santa Rosa Sonoma Co AP, CA | USW00023213 | March 2 | November 20 | 262 days |
| Santa Rosa, CA | USC00047965 | February 25 | December 1 | 279 days |
| Sonoma, CA | USC00048351 | March 2 | November 27 | 270 days |
These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.
Every ZIP code in Santa Rosa-Petaluma, CA
Zones are published per ZIP code, not per metro area, so this is the exact answer rather than the metro area's average. The station column is the nearest one to that ZIP code's centroid and how far away it is — the same figure the tools use, shown here so you can see which ZIP codes are well covered and which are reaching.
| ZIP code | USDA zone | Nearest NOAA station | Distance |
|---|---|---|---|
| 94515 | 9b | Calistoga, CA | 4.6 km |
| 94922 | 9b | Occidental, CA | 3.5 km |
| 94923 | 10a | Bodega 6 Wsw, CA | 4.1 km |
| 94928 | 9a | Petaluma AP, CA | 12.3 km |
| 94931 | 9a | Petaluma AP, CA | 12.1 km |
| 94951 | 9b | Petaluma AP, CA | 7.9 km |
| 94954 | 9b | Petaluma AP, CA | 5.1 km |
| 94972 | 9b | Occidental, CA | 5.9 km |
| 95401 | 9a | Santa Rosa Sonoma Co AP, CA | 6.3 km |
| 95403 | 9a | Santa Rosa Sonoma Co AP, CA | 4.9 km |
| 95404 | 9b | Santa Rosa, CA | 8.0 km |
| 95405 | 9a | Santa Rosa, CA | 4.3 km |
| 95407 | 9a | Santa Rosa, CA | 7.4 km |
| 95409 | 9b | Saint Helena, CA | 10.5 km |
| 95412 | 9b | Ft Ross, CA | 22.8 km |
| 95419 | 9b | Occidental, CA | 4.2 km |
| 95421 | 9b | Ft Ross, CA | 9.3 km |
| 95425 | 9b | Cloverdale, CA | 4.7 km |
| 95430 | 9b | Occidental, CA | 11.0 km |
| 95431 | 9b | Sonoma, CA | 7.3 km |
| 95436 | 9b | Graton, CA | 7.2 km |
| 95439 | 9a | Santa Rosa Sonoma Co AP, CA | 3.3 km |
| 95441 | 9b | Cloverdale, CA | 8.2 km |
| 95442 | 9b | Sonoma, CA | 10.0 km |
| 95444 | 9a | Graton, CA | 0.5 km |
| 95446 | 9b | Occidental, CA | 15.4 km |
| 95448 | 9b | Healdsburg, CA | 2.1 km |
| 95450 | 10a | Ft Ross, CA | 3.2 km |
| 95452 | 9b | Saint Helena, CA | 10.3 km |
| 95462 | 9b | Occidental, CA | 10.9 km |
| 95465 | 10a | Occidental, CA | 7.8 km |
| 95471 | 9b | Healdsburg, CA | 14.3 km |
| 95472 | 9a | Graton, CA | 3.5 km |
| 95476 | 9b | Sonoma, CA | 4.8 km |
| 95480 | 10a | Ft Ross, CA | 21.7 km |
| 95486 | 9b | Occidental, CA | 11.0 km |
| 95492 | 9a | Santa Rosa Sonoma Co AP, CA | 3.0 km |
| 95497 | 10a | Ft Ross, CA | 29.9 km |
ZIP-code positions are area centroids, so a large rural ZIP code's listed distance is measured from the middle of its area rather than from any particular address in it.
Your own ZIP
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 Santa Rosa-Petaluma, CA 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.
Other places to compare
These metros span exactly the same zones — 9a–10a — so the same plants are in and out of range across them. The freeze dates and the spring calendar are their own.
- Santa Cruz-Watsonville, CA — zones 9a–10a
- Yuma, AZ — zones 9a–10a
- Houston-Pasadena-The Woodlands, TX — zones 9a–10a
- Phoenix-Mesa-Chandler, AZ — zones 9a–10a
- New Orleans-Metairie, LA — zones 9a–10a
- San Jose-Sunnyvale-Santa Clara, CA — zones 9a–10a
Gardening in California — zones 5b– 11a covers the whole state: how its 1,788 ZIP codes divide between 12 hardiness zones, and the freeze dates across every NOAA station in it.
Other metro areas in CA:
- Salinas, CA Zones 8b–10b
- Oxnard-Thousand Oaks-Ventura, CA Zones 7b, 8b, 9b, 10a, 10b
- Stockton-Lodi, CA Zone 9b
- Modesto, CA Zone 9b
- Redding, CA Zones 7a, 7b, 8b, 9a, 9b
- Santa Maria-Santa Barbara, CA Zones 9a–10b
- San Luis Obispo-Paso Robles, CA Zones 8b–10a
- Yuba City, CA Zones 9a–9b
- Chico, CA Zones 8b–9b
- Merced, CA Zones 9a–9b
- Santa Cruz-Watsonville, CA Zones 9a–10a
- El Centro, CA Zones 9b–10a
Gear
If you want to act on this
Each link opens an Amazon search rather than a product we picked. We have not tested these and do not rank them — the search is the honest version, and you choose.
- Row cover and frost clothThe season here closes at the first fall freeze dated above — a cover buys back some of those days at the end.
As an Amazon Associate we earn from qualifying purchases. That costs you nothing extra, and it buys no influence over anything on this site: the dates come from NOAA normals and the zones from the USDA, and no product affects either.
Sources
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.