Napa, California planting calendar and frost dates
Napa is in USDA hardiness zone 9b. The last spring frost typically comes around February 12 and the first fall frost around December 4, giving about 299 frost-free days a year.
- Hardiness zone
- Zone 9b
- Typical last frost
- February 12
- Typical first frost
- December 4
- Frost-free season
- 299 days
Frost dates in Napa
Last spring frost
- January 3Risky: frost later than this in 9 years out of 10
- February 12Typical: a later frost in half of years
- March 13Safe: a later frost only 1 year in 10
First fall frost
- November 15Risky: frost earlier than this 1 year in 10
- December 4Typical: an earlier frost in half of years
- New yearLate: in about 1 year in 10, the first frost waits until after December 31
The growing season between the typical last and first frosts is about 299 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 11 and returns around December 19.
NOAA U.S. Climate Normals 1991-2020 for Napa State Hospital, 1.8 miles SE 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 Napa
January
Start indoors: black-eyed susans, cabbages, 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, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garlic, gladioli, grapes, grass seed, green onions, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, potatoes, radishes, ranunculus, raspberries, rhubarb, roses, snapdragons, spinach, strawberries, swiss chard, turnips, wildflowers
February
Start indoors: eggplants, peppers, tomatoes
Plant or sow outdoors: asparagus, beets, carrots, cauliflower, chives, cilantro, dahlias, dill, figs, garden mums, gladioli, grapes, green onions, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, petunias, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, swiss chard, thyme, zinnias
March
Start indoors: basil, cantaloupes, celery, cucumbers, eggplants, peppers, pumpkins, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, garden mums, ginger, green onions, kentucky bluegrass, st. augustinegrass, sunflowers, sweet peas, tall fescue
April
Start indoors: cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: basil, cantaloupes, cucumbers, eggplants, green beans, green onions, peppers, pumpkins, st. augustinegrass, tomatoes, watermelons, winter squash, zucchini
May
Plant or sow outdoors: basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, green beans, okra, peanuts, peppers, pumpkins, sweet potatoes, tomatoes, watermelons, winter squash, zoysiagrass, 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, peppers, potatoes, sweet corn, tomatoes
September
Plant for fall: bearded irises, beets, broccoli, brussels sprouts, cabbages, carrots, cauliflower, collard greens, cucumbers, green beans, lettuce, peas, peppers, radishes, snapdragons, spinach, sweet corn, swiss chard, turnips, zucchini
October
Start indoors: onions
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, 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, swiss chard, tall fescue, tulips, turnips
November
Start indoors: broccoli, cauliflower, collard greens, kale, leeks, onions, petunias, ranunculus
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 Napa
All 2 of Napa's main ZIP codes take their frost dates from Napa State Hospital, so the dates on this page apply across the city. Every one of them is in zone 9b.
Planting dates for popular crops in Napa
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Feb 28 to Mar 14 | Apr 25 to May 9 | Aug 21 to 28 |
| Strawberries | — | Jan 1 to 15 | — |
| Lettuce | Dec 18 to Jan 1 | Feb 5 to 19 | Sep 4 to Oct 9 |
| Cilantro | Jan 1 to 15 | Feb 12 to 19 | — |
| Basil | Mar 7 to 21 | Apr 25 to May 2 | — |
| Potatoes | — | Jan 24 to 31 | Aug 14 to 21 |
| Garlic | — | Jan 1 to 15 | Dec 4 to 18 |
| Onions | Oct 23 to Dec 4 | Jan 15 to 29 | — |
| Cucumbers | Mar 28 to Apr 11 | Apr 25 to May 9 | Sep 4 to 18 |
| Pumpkins | Mar 28 to Apr 11 | Apr 25 to May 9 | — |
| Peppers | Feb 7 to Mar 7 | Apr 25 to May 9 | Aug 14 to Sep 11 |
| Carrots | — | Jan 22 to Feb 12 | Sep 11 to Oct 2 |
| Sweet Potatoes | — | May 27 to Jun 3 | — |
| Watermelons | Mar 21 to Apr 4 | Apr 25 to May 9 | — |
| Sweet Corn | — | Feb 12 to 26 | Aug 28 to Sep 11 |
| Green Beans | — | Apr 25 to May 9 | Sep 11 to 18 |
| Zucchini | Mar 28 to Apr 11 | Apr 25 to May 9 | Sep 11 to 25 |
| Broccoli | Nov 27 to Dec 18 | Jan 15 to 29 | Sep 18 to Oct 16 |
| Peas | — | Jan 1 to 15 | Sep 11 to 25 |
| Spinach | Jan 1 to 8 | Feb 5 to 19 | Sep 25 to Oct 30 |
| Sunflowers | — | Feb 12 to Mar 5 | — |
| Zinnias | Jan 15 to 22 | Feb 12 to 26 | — |
| Tulips | — | — | Oct 23 to Dec 18 |
| Daffodils | — | — | Oct 23 to Dec 4 |
| Grass Seed | — | Jan 1 to 15 | Oct 23 to Nov 6 |
Nearby cities
- Vallejo, CA zone 9b, last frost Mar 5
- Fairfield, CA zone 9b, last frost Jan 15
- Petaluma, CA zone 9b, last frost Feb 28
- Vacaville, CA zone 9b, last frost Jan 15
- Novato, CA zone 9b, last frost Feb 28
- Richmond, CA zone 10a
Planting in CaliforniaAbout zone 9bPrintable calendar for Napa
Questions
When is the last frost in Napa?
Around February 12 in a typical year, based on NOAA's 1991-2020 records for Napa State Hospital. There is still a 1 in 10 chance of frost after March 13.
What planting zone is Napa 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 Napa?
Start seeds indoors February 28 to March 14 and set plants out April 25 to May 9.
When is the first frost in Napa?
Around December 4 in a typical year, and before November 15 about 1 year in 10.