When to plant in Healdsburg, CA
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in Healdsburg, California — is derived from the closest NOAA station with complete climate normals.
A generous ~290-day season lets Healdsburg gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9b is warm enough that Healdsburg can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Healdsburg is now 6 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
HEALDSBURG · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Healdsburg’s own odds, recorded at HEALDSBURG.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 20 | Mar 29 | Feb 27 | Nov 1 | Nov 16 | Dec 2 |
| 32°F | Mar 17 | Feb 15 | Jan 4 | Nov 14 | Dec 2 | Jan 1 |
| 28°F | Feb 2 | Jan 7 | Dec 14 | Nov 28 | Dec 17 | Jan 12 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Healdsburg, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 21 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Healdsburg planting FAQ
When is the last spring frost in Healdsburg, CA?
Healdsburg's average last spring frost falls near February 15 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Healdsburg, CA?
In Healdsburg, the first 32°F freeze of fall lands around December 2 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Healdsburg in?
Healdsburg is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Healdsburg?
There are roughly 290 frost-free days in Healdsburg (a long growing season), running from the average last frost around February 15 to the first fall frost near December 2.
When should I plant tomatoes in Healdsburg?
In Healdsburg, start tomato seeds indoors around December 21–January 4, then transplant seedlings outdoors around February 22 once the danger of frost has passed.
Never miss a window in Healdsburg
An email when it’s time to start seeds, transplant, and sow — timed to Healdsburg’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Windsor · 10 km
- Santa Rosa · 24 km
- Rohnert Park · 34 km
- Clearlake · 43 km
- Petaluma · 47 km
- Sonoma · 51 km
- Napa · 61 km
- Ukiah · 65 km
Frost dates recorded at HEALDSBURG, 1 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Healdsburg, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00043875. Retrieved from https://blissgarden.com/california/healdsburg.