San Luis Obispo, California planting calendar and frost dates
San Luis Obispo is in USDA hardiness zone 9b. The last spring frost typically comes around January 31 and the first fall frost around December 11, giving about 319 frost-free days a year.
- Hardiness zone
- Zone 9b
- Typical last frost
- January 31
- Typical first frost
- December 11
- Frost-free season
- 319 days
Frost dates in San Luis Obispo
Last spring frost
- December 23Risky: frost later than this in 9 years out of 10
- January 31Typical: a later frost in half of years
- March 7Safe: a later frost only 1 year in 10
First fall frost
- November 20Risky: frost earlier than this 1 year in 10
- December 11Typical: 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 319 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 3 and returns around December 28.
NOAA U.S. Climate Normals 1991-2020 for San Luis Obispo Airport, 1.4 miles W 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 San Luis Obispo
January
Start indoors: cilantro, ginger, marigolds, nasturtiums, ranunculus, zinnias
Plant or sow outdoors: asparagus, avocados, beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garden mums, garlic, gladioli, grapes, grass seed, green onions, hollyhocks, kale, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, peas, petunias, poppies, potatoes, radishes, ranunculus, raspberries, rhubarb, rosemary, roses, sage, snapdragons, spinach, strawberries, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, turnips, wildflowers, zinnias
February
Plant or sow outdoors: avocados, 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
March
Start indoors: basil, eggplants, peppers, tomatoes
Plant or sow outdoors: ginger, st. augustinegrass
April
Start indoors: basil, cantaloupes, celery, cucumbers, pumpkins, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: st. augustinegrass
May
Start indoors: cosmos, cucumbers, okra, pumpkins, winter squash, zucchini
Plant or sow outdoors: basil, cantaloupes, cucumbers, eggplants, green beans, peppers, pumpkins, tomatoes, watermelons, winter squash, zucchini
June
July
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, okra, peanuts, sweet potatoes, zoysiagrass
August
Plant or sow outdoors: bermudagrass, centipedegrass, zoysiagrass
Plant for fall: potatoes
September
Plant for fall: bearded irises, broccoli, brussels sprouts, carrots, collard greens, lettuce, peas, snapdragons, sweet corn, swiss chard
October
Start indoors: onions
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hydrangeas, kale, kentucky bluegrass, lettuce, lilies, ornamental alliums, peas, peonies, perennial ryegrass, radishes, roses, saffron, snapdragons, spinach, swiss chard, tall fescue, tulips, turnips
November
Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, petunias, ranunculus, rosemary, snapdragons
Plant for fall: cabbages, cauliflower, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, saffron, spinach, tall fescue, tulips
December
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
Plant or sow outdoors: asparagus, black-eyed susans, blueberries, garlic, grapes, grass seed, green onions, hollyhocks, kale, kentucky bluegrass, onions, peas, poppies, raspberries, rhubarb, strawberries, sweet peas, tall fescue, turnips, wildflowers
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
Frost dates and zones by ZIP code in San Luis Obispo
San Luis Obispo's 2 main ZIP codes take their frost dates from 2 different NOAA stations: the typical last frost ranges from January 16 in 93405 to January 31 in 93401. Every one of them is in zone 9b.
Planting dates for popular crops in San Luis Obispo
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 22 to Apr 5 | May 17 to 31 | — |
| Strawberries | — | Dec 20 to Jan 3 | — |
| Lettuce | Dec 6 to 20 | Jan 24 to Feb 7 | Sep 11 to Oct 16 |
| Cilantro | Dec 20 to Jan 3 | Jan 31 to Feb 7 | — |
| Basil | Mar 29 to Apr 12 | May 17 to 24 | — |
| Potatoes | — | Jan 10 to 17 | Aug 21 to 28 |
| Garlic | — | Dec 20 to Jan 3 | Dec 11 to 25 |
| Onions | Oct 11 to Nov 22 | Jan 3 to 17 | — |
| Cucumbers | Apr 19 to May 3 | May 17 to 31 | — |
| Pumpkins | Apr 19 to May 3 | May 17 to 31 | — |
| Peppers | Mar 1 to 29 | May 17 to 31 | — |
| Carrots | — | Jan 10 to 31 | Sep 18 to Oct 9 |
| Sweet Potatoes | — | Jul 1 to 8 | — |
| Watermelons | Apr 12 to 26 | May 17 to 31 | — |
| Sweet Corn | — | Jan 31 to Feb 14 | Sep 4 to 18 |
| Green Beans | — | May 17 to 31 | — |
| Zucchini | Apr 19 to May 3 | May 17 to 31 | — |
| Broccoli | Nov 15 to Dec 6 | Jan 3 to 17 | Sep 25 to Oct 23 |
| Peas | — | Dec 20 to Jan 3 | Sep 18 to Oct 2 |
| Spinach | Dec 20 to 27 | Jan 24 to Feb 7 | Oct 2 to Nov 6 |
| Sunflowers | — | Jan 31 to Feb 21 | — |
| Zinnias | Jan 3 to 10 | Jan 31 to Feb 14 | — |
| Tulips | — | — | Oct 30 to Dec 25 |
| Daffodils | — | — | Oct 30 to Dec 11 |
| Grass Seed | — | Dec 20 to Jan 3 | Oct 30 to Nov 13 |
Nearby cities
- Santa Maria, CA zone 9b, last frost Feb 4
- Santa Barbara, CA zone 10a
- Delano, CA zone 9b, last frost Jan 31
- Bakersfield, CA zone 9b, last frost Jan 17
- Hanford, CA zone 9a, last frost Feb 7
- Tulare, CA zone 9b, last frost Feb 15
Planting in CaliforniaAbout zone 9bPrintable calendar for San Luis Obispo
Questions
When is the last frost in San Luis Obispo?
Around January 31 in a typical year, based on NOAA's 1991-2020 records for San Luis Obispo Airport. There is still a 1 in 10 chance of frost after March 7.
What planting zone is San Luis Obispo 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 San Luis Obispo?
Start seeds indoors March 22 to April 5 and set plants out May 17 to 31.
When is the first frost in San Luis Obispo?
Around December 11 in a typical year, and before November 20 about 1 year in 10.