San Marcos, California planting calendar and frost dates
San Marcos is in USDA hardiness zone 10a. The last spring frost typically comes around January 23 and the first fall frost around December 11, giving about 325 frost-free days a year.
- Hardiness zone
- Zone 10a
- Typical last frost
- January 23
- Typical first frost
- December 11
- Frost-free season
- 325 days
Frost dates in San Marcos
Last spring frost
- December 22Risky: frost later than this in 9 years out of 10
- January 23Typical: a later frost in half of years
- February 22Safe: a later frost only 1 year in 10
First fall frost
- November 21Risky: 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 325 days. Frost here means a low of 32°F at the weather station.
NOAA U.S. Climate Normals 1991-2020 for Oceanside Muni Airport, 2.4 miles NE of the city center. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers. San Marcos shares this station with Oceanside, so the two cities have the same frost dates and planting calendar.
What to plant each month in San Marcos
January
Start indoors: ginger, ranunculus, zinnias
Plant or sow outdoors: asparagus, avocados, 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
February
Start indoors: eggplants, peppers
Plant or sow outdoors: avocados, garden mums, grapes, green onions, lavenders, lilies, marigolds, mints, nasturtiums, oregano, parsley, petunias, rosemary, sage, st. augustinegrass, sunflowers, sweet corn, thyme, zinnias
March
Start indoors: basil, cantaloupes, celery, eggplants, peppers, tomatoes, watermelons
Plant or sow outdoors: ginger, st. augustinegrass
April
Start indoors: cantaloupes, celery, cucumbers, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: st. augustinegrass
May
Plant or sow outdoors: basil, cantaloupes, cucumbers, eggplants, green beans, peppers, pumpkins, 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, okra, zoysiagrass
August
September
Plant for fall: bearded irises, broccoli, brussels sprouts, carrots, collard greens, cucumbers, green beans, lettuce, peas, peppers, snapdragons, sweet corn, swiss chard, tomatoes, zucchini
October
Start indoors: collard greens, leeks, onions, petunias, ranunculus
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, zucchini
November
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: 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, 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, kentucky bluegrass, leeks, onions, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, sweet peas, swiss chard, 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 Marcos
San Marcos's 2 main ZIP codes take their frost dates from 2 different NOAA stations. Every one of them is in zone 10a.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 92069 | 10a | Escondido #2, 5.4 mi SE | Rare | Rare |
| 92078 | 10a | Oceanside Muni Airport, 2.4 mi NE | Jan 23 | Dec 11 |
Oceanside Muni Airport also supplies the frost dates for Oceanside, Carlsbad, Vista and Encinitas, so their planting calendars match San Marcos's.
Planting dates for popular crops in San Marcos
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 6 to 20 | May 1 to 15 | Aug 28 to Sep 4 |
| Strawberries | — | Dec 12 to 26 | — |
| Lettuce | Nov 28 to Dec 12 | Jan 16 to 30 | Sep 11 to Oct 16 |
| Cilantro | Dec 12 to 26 | Jan 23 to 30 | — |
| Basil | Mar 13 to 27 | May 1 to 8 | — |
| Potatoes | — | Jan 2 to 9 | Aug 21 to 28 |
| Garlic | — | Dec 12 to 26 | Dec 11 to 25 |
| Onions | Oct 3 to Nov 14 | Dec 26 to Jan 9 | — |
| Cucumbers | Apr 3 to 17 | May 1 to 15 | Sep 11 to 25 |
| Pumpkins | Apr 3 to 17 | May 1 to 15 | — |
| Peppers | Feb 13 to Mar 13 | May 1 to 15 | Aug 21 to Sep 18 |
| Carrots | — | Jan 2 to 23 | Sep 18 to Oct 9 |
| Sweet Potatoes | — | Jun 13 to 20 | — |
| Watermelons | Mar 27 to Apr 10 | May 1 to 15 | — |
| Sweet Corn | — | Jan 23 to Feb 6 | Sep 4 to 18 |
| Green Beans | — | May 1 to 15 | Sep 18 to 25 |
| Zucchini | Apr 3 to 17 | May 1 to 15 | Sep 18 to Oct 2 |
| Broccoli | Nov 7 to 28 | Dec 26 to Jan 9 | Sep 25 to Oct 23 |
| Peas | — | Dec 12 to 26 | Sep 18 to Oct 2 |
| Spinach | Dec 12 to 19 | Jan 16 to 30 | Oct 2 to Nov 6 |
| Sunflowers | — | Jan 23 to Feb 13 | — |
| Zinnias | Dec 26 to Jan 2 | Jan 23 to Feb 6 | — |
| Tulips | — | — | Oct 30 to Dec 25 |
| Daffodils | — | — | Oct 30 to Dec 11 |
| Grass Seed | — | Dec 12 to 26 | Oct 30 to Nov 13 |
Nearby cities
- Escondido, CA zone 9b
- Vista, CA zone 10a, last frost Jan 23
- Carlsbad, CA zone 10a, last frost Jan 23
- Encinitas, CA zone 10a, last frost Jan 23
- Oceanside, CA zone 10a, last frost Jan 23
- San Diego, CA zone 10b
Planting in CaliforniaAbout zone 10aPrintable calendar for San Marcos
Questions
When is the last frost in San Marcos?
Around January 23 in a typical year, based on NOAA's 1991-2020 records for Oceanside Muni Airport. There is still a 1 in 10 chance of frost after February 22.
What planting zone is San Marcos in?
USDA hardiness zone 10a (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 Marcos?
Start seeds indoors March 6 to 20 and set plants out May 1 to 15.
When is the first frost in San Marcos?
Around December 11 in a typical year, and before November 21 about 1 year in 10.