Santa Rosa, California planting calendar and frost dates
Santa Rosa is in USDA hardiness zone 9b. The last spring frost typically comes around February 25 and the first fall frost around December 1, giving about 279 frost-free days a year.
- Typical last frost
- February 25
- Typical first frost
- December 1
- Frost-free season
- 279 days
Frost dates in Santa Rosa
Last spring frost
- January 21Risky: frost later than this in 9 years out of 10
- February 25Typical: a later frost in half of years
- March 29Safe: a later frost only 1 year in 10
First fall frost
- November 10Risky: frost earlier than this 1 year in 10
- December 1Typical: an earlier frost in half of years
- December 24Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 279 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 20 and returns around December 16.
NOAA U.S. Climate Normals 1991-2020 for Santa Rosa, 1.1 miles N of the city center. 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 Santa Rosa
January
Start indoors: black-eyed susans, cabbages, cauliflower, chives, cilantro, collard greens, ginger, lettuce, marigolds, nasturtiums, ranunculus, sage, snapdragons, spinach, swiss chard, zinnias
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, blueberries, broccoli, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, green onions, hollyhocks, kale, leeks, onions, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
February
Start indoors: ginger, peppers, 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, ginger, gladioli, grapes, green onions, kentucky bluegrass, lavenders, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, petunias, ranunculus, rosemary, sage, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, zinnias
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: ginger, green onions, kentucky bluegrass, st. augustinegrass, sweet peas, tall fescue
May
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, celery, centipedegrass, cosmos, okra, peanuts, sweet potatoes, zoysiagrass
July
Plant or sow outdoors: bermudagrass, centipedegrass, zoysiagrass
August
Plant for fall: brussels sprouts, potatoes, sweet corn
September
Plant for fall: bearded irises, beets, broccoli, brussels sprouts, cabbages, carrots, cauliflower, collard greens, daylilies, kale, lettuce, peas, radishes, 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, hydrangeas, kale, kentucky bluegrass, lettuce, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, roses, saffron, snapdragons, spinach, tall fescue, tulips, turnips
November
Start indoors: onions
Plant for fall: crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, saffron, tall fescue, tulips
December
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, collard greens, kale, leeks, lettuce, marigolds, onions, oregano, parsley, petunias, ranunculus, rosemary, sage, snapdragons
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
Frost dates and zones by ZIP code in Santa Rosa
All 6 of Santa Rosa's main ZIP codes take their frost dates from Santa Rosa, so the dates on this page apply across the city. The hardiness zone is 9a in 95401, 95403, 95405, 95407, and 9b in 95404, 95409.
Planting dates for popular crops in Santa Rosa
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 14 to 28 | May 9 to 23 | — |
| Strawberries | — | Jan 14 to 28 | — |
| Lettuce | Dec 31 to Jan 14 | Feb 18 to Mar 4 | Sep 1 to Oct 6 |
| Cilantro | Jan 14 to 28 | Feb 25 to Mar 4 | — |
| Basil | Mar 21 to Apr 4 | May 9 to 16 | — |
| Potatoes | — | Feb 4 to 11 | Aug 11 to 18 |
| Garlic | — | Jan 14 to 28 | Dec 1 to 15 |
| Onions | Nov 5 to Dec 17 | Jan 28 to Feb 11 | — |
| Cucumbers | Apr 11 to 25 | May 9 to 23 | — |
| Pumpkins | Apr 11 to 25 | May 9 to 23 | — |
| Peppers | Feb 21 to Mar 21 | May 9 to 23 | — |
| Carrots | — | Feb 4 to 25 | Sep 8 to 29 |
| Sweet Potatoes | — | Jun 9 to 16 | — |
| Watermelons | Apr 4 to 18 | May 9 to 23 | — |
| Sweet Corn | — | Feb 25 to Mar 11 | Aug 25 to Sep 8 |
| Green Beans | — | May 9 to 23 | — |
| Zucchini | Apr 11 to 25 | May 9 to 23 | — |
| Broccoli | Dec 10 to 31 | Jan 28 to Feb 11 | Sep 15 to Oct 13 |
| Peas | — | Jan 14 to 28 | Sep 8 to 22 |
| Spinach | Jan 14 to 21 | Feb 18 to Mar 4 | Sep 22 to Oct 27 |
| Sunflowers | — | Feb 25 to Mar 18 | — |
| Zinnias | Jan 28 to Feb 4 | Feb 25 to Mar 11 | — |
| Tulips | — | — | Oct 20 to Dec 15 |
| Daffodils | — | — | Oct 20 to Dec 1 |
| Grass Seed | — | Jan 14 to 28 | Oct 20 to Nov 3 |
Nearby cities
- Petaluma, CA zone 9b, last frost Feb 28
- Napa, CA zone 9b, last frost Feb 12
- Novato, CA zone 9b, last frost Feb 28
- Vallejo, CA zone 9b, last frost Mar 5
- San Rafael, CA zone 10a, last frost Jan 16
- Fairfield, CA zone 9b, last frost Jan 15
Planting in CaliforniaAbout zone 9bPrintable calendar for Santa Rosa
Questions
When is the last frost in Santa Rosa?
Around February 25 in a typical year, based on NOAA's 1991-2020 records for Santa Rosa. There is still a 1 in 10 chance of frost after March 29.
What planting zone is Santa Rosa in?
USDA hardiness zone 9b (2023 map), with parts of the city in zone 9a. The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Santa Rosa?
Start seeds indoors March 14 to 28 and set plants out May 9 to 23.
When is the first frost in Santa Rosa?
Around December 1 in a typical year, and before November 10 about 1 year in 10.