Petaluma, California planting calendar and frost dates
Petaluma is in USDA hardiness zone 9b. The last spring frost typically comes around February 28 and the first fall frost around November 25, giving about 271 frost-free days a year.
- Hardiness zone
- Zone 9b
- Typical last frost
- February 28
- Typical first frost
- November 25
- Frost-free season
- 271 days
Frost dates in Petaluma
Last spring frost
- January 24Risky: frost later than this in 9 years out of 10
- February 28Typical: a later frost in half of years
- April 6Safe: a later frost only 1 year in 10
First fall frost
- November 9Risky: frost earlier than this 1 year in 10
- November 25Typical: an earlier frost in half of years
- December 16Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 271 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around January 17 and returns around December 9.
NOAA U.S. Climate Normals 1991-2020 for Petaluma Airport, 3.2 miles WNW of the city center and 237 feet lower. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers.
What to plant each month in Petaluma
January
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, cilantro, collard greens, leeks, lettuce, marigolds, nasturtiums, oregano, parsley, petunias, ranunculus, rosemary, sage, snapdragons, spinach, swiss chard, zinnias
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, onions, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
February
Start indoors: ginger, ranunculus, zinnias
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garden mums, gladioli, grapes, green onions, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, swiss chard, thyme, turnips, zinnias
March
Start indoors: basil, celery, eggplants, peppers, tomatoes
Plant or sow outdoors: asparagus, chives, cilantro, dahlias, dill, garden mums, gladioli, grapes, green onions, lavenders, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, petunias, ranunculus, rosemary, sage, spinach, sunflowers, sweet corn, swiss chard, thyme, zinnias
April
Start indoors: basil, cantaloupes, celery, cucumbers, pumpkins, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: ginger, green onions, kentucky bluegrass, st. augustinegrass, sweet peas, tall fescue
May
Start indoors: cosmos, cucumbers, okra, pumpkins, winter squash, zucchini
Plant or sow outdoors: basil, cantaloupes, cucumbers, eggplants, green beans, peppers, pumpkins, st. augustinegrass, tomatoes, watermelons, winter squash, zucchini
June
Plant or sow outdoors: bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, green beans, okra, peanuts, peppers, pumpkins, sweet potatoes, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
July
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, okra, peanuts, zoysiagrass
August
Plant for fall: brussels sprouts, collard greens, lettuce, potatoes, sweet corn, swiss chard
September
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, daylilies, hostas, hydrangeas, kale, lettuce, peas, radishes, roses, saffron, snapdragons, spinach, sweet corn, swiss chard, turnips
October
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, roses, saffron, spinach, tall fescue, tulips, turnips
November
Start indoors: onions
Plant for fall: crocuses, daffodils, daylilies, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
December
Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, petunias, ranunculus, rosemary, snapdragons
Plant for fall: crocuses, garlic, hyacinths, ornamental alliums, tulips
Frost dates and zones by ZIP code in Petaluma
All 2 of Petaluma's main ZIP codes take their frost dates from Petaluma Airport, so the dates on this page apply across the city. Every one of them is in zone 9b.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 94952 | 9b | Petaluma Airport, 8.4 mi E | Feb 28 | Nov 25 |
| 94954 | 9b | Petaluma Airport, 3.2 mi WNW | Feb 28 | Nov 25 |
Petaluma Airport also supplies the frost dates for Novato, so their planting calendars match Petaluma's.
Planting dates for popular crops in Petaluma
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 24 to Apr 7 | May 19 to Jun 2 | — |
| Strawberries | — | Jan 17 to 31 | — |
| Lettuce | Jan 3 to 17 | Feb 21 to Mar 7 | Aug 26 to Sep 30 |
| Cilantro | Jan 17 to 31 | Feb 28 to Mar 7 | — |
| Basil | Mar 31 to Apr 14 | May 19 to 26 | — |
| Potatoes | — | Feb 7 to 14 | Aug 5 to 12 |
| Garlic | — | Jan 17 to 31 | Nov 25 to Dec 9 |
| Onions | Nov 8 to Dec 20 | Jan 31 to Feb 14 | — |
| Cucumbers | Apr 21 to May 5 | May 19 to Jun 2 | — |
| Pumpkins | Apr 21 to May 5 | May 19 to Jun 2 | — |
| Peppers | Mar 3 to 31 | May 19 to Jun 2 | — |
| Carrots | — | Feb 7 to 28 | Sep 2 to 23 |
| Sweet Potatoes | — | Jun 21 to 28 | — |
| Watermelons | Apr 14 to 28 | May 19 to Jun 2 | — |
| Sweet Corn | — | Feb 28 to Mar 14 | Aug 19 to Sep 2 |
| Green Beans | — | May 19 to Jun 2 | — |
| Zucchini | Apr 21 to May 5 | May 19 to Jun 2 | — |
| Broccoli | Dec 13 to Jan 3 | Jan 31 to Feb 14 | Sep 9 to Oct 7 |
| Peas | — | Jan 17 to 31 | Sep 2 to 16 |
| Spinach | Jan 17 to 24 | Feb 21 to Mar 7 | Sep 16 to Oct 21 |
| Sunflowers | — | Feb 28 to Mar 21 | — |
| Zinnias | Jan 31 to Feb 7 | Feb 28 to Mar 14 | — |
| Tulips | — | — | Oct 14 to Dec 9 |
| Daffodils | — | — | Oct 14 to Nov 25 |
| Grass Seed | — | Jan 17 to 31 | Oct 14 to 28 |
Nearby cities
- Novato, CA zone 9b, last frost Feb 28
- Santa Rosa, CA zone 9b, last frost Feb 25
- Napa, CA zone 9b, last frost Feb 12
- San Rafael, CA zone 10a, last frost Jan 16
- Vallejo, CA zone 9b, last frost Mar 5
- Richmond, CA zone 10a
Planting in CaliforniaAbout zone 9bPrintable calendar for Petaluma
Questions
When is the last frost in Petaluma?
Around February 28 in a typical year, based on NOAA's 1991-2020 records for Petaluma Airport. There is still a 1 in 10 chance of frost after April 6.
What planting zone is Petaluma in?
USDA hardiness zone 9b (2023 map). The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Petaluma?
Start seeds indoors March 24 to April 7 and set plants out May 19 to June 2.
When is the first frost in Petaluma?
Around November 25 in a typical year, and before November 9 about 1 year in 10.