Frost Dates for Alpine, CA 91901
Last spring frost January 14 · First fall frost December 30 · 350 frost-free days · USDA Zone 9b
ZIP 91901 has about 18,200 people.
Very long season: 350 frost-free days.
Frost probability for 91901
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | March 28 | January 14 | — |
| Fall (first frost) | November 13 | December 30 | — |
Dates come from NOAA 1971–2000 freeze probabilities at ALPINE (5.9 km away); the 50% date is the median year.
Which crops fit a 350-day season in Alpine
In Alpine (350 frost-free days, a very long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Dec 10 | Jan 28–Feb 4 | 308 | fits: 80 days to maturity, 308 available after Jan 28. | Aug 30 |
| Pepper | Dec 3 | Jan 28–Feb 4 | 308 | fits: 75 days to maturity, 308 available after Jan 28. | Sep 4 |
| Lettuce | Nov 19 | Dec 17–Dec 24 | 385 | two-plantings: Plant Dec 17 and again by Nov 8; both mature before Jan 6. | Nov 8 |
| Carrots | — | Dec 24–Dec 31 | 392 | fits: 70 days to maturity, 392 available after Dec 24. | Oct 28 |
| Cucumber | Dec 24 | Jan 28–Feb 4 | 322 | two-plantings: Plant Jan 28 and again by Oct 3; both mature before Dec 16. | Oct 3 |
| Beans | — | Jan 21–Feb 4 | 336 | two-plantings: Plant Jan 21 and again by Oct 10; both mature before Dec 23. | Oct 10 |
| Peas | — | Nov 19–Jan 28 | 413 | fits: 65 days to maturity, 413 available after Nov 19. | Oct 19 |
| Zucchini | Dec 31 | Jan 28–Feb 4 | 322 | two-plantings: Plant Jan 28 and again by Oct 8; both mature before Dec 16. | Oct 8 |
| Onion | Oct 22 | Dec 17–Dec 31 | 385 | fits: 100 days to maturity, 385 available after Dec 17. | — |
| Spinach | — | Nov 19–Jan 7 | 427 | two-plantings: Plant Nov 19 and again by Nov 27; both mature before Jan 20. | Nov 27 |
| Kale | Nov 5 | Dec 17–Dec 31 | 399 | two-plantings: Plant Dec 17 and again by Nov 12; both mature before Jan 20. | Nov 12 |
| Broccoli | Nov 19 | Dec 17–Dec 31 | 385 | fits: 80 days to maturity, 385 available after Dec 17. | Oct 4 |
| Cabbage | Nov 19 | Dec 17–Dec 31 | 399 | fits: 70 days to maturity, 399 available after Dec 17. | Oct 28 |
| Radish | — | Nov 19–Feb 11 | 413 | two-plantings: Plant Nov 19 and again by Nov 28; both mature before Jan 6. | Nov 28 |
| Beets | — | Nov 19–Feb 11 | 413 | two-plantings: Plant Nov 19 and again by Oct 29; both mature before Jan 6. | Oct 29 |
| Potatoes | — | Dec 31–Jan 7 | 371 | fits: 90 days to maturity, 371 available after Dec 31. | — |
| Garlic | — | Dec 30 | 455 | overwinter: Plant Dec 30 to Jan 20; harvest the following summer. | Jan 20 |
| Strawberry | — | Dec 10–Feb 4 | 406 | perennial: A perennial: plant Dec 10; it fruits from the following year and keeps producing for several years. | — |
| Corn | Dec 17 | Jan 21–Jan 28 | 322 | fits: 75 days to maturity, 322 available after Jan 21. | Sep 11 |
| Pumpkin | Dec 31 | Jan 28–Jan 28 | 315 | fits: 100 days to maturity, 315 available after Jan 28. | Aug 17 |
| Cauliflower | Dec 3 | Jan 7–Jan 21 | 364 | fits: 75 days to maturity, 364 available after Jan 7. | Oct 9 |
| Swiss Chard | Nov 19 | Dec 31–Dec 31 | 371 | two-plantings: Plant Dec 31 and again by Oct 29; both mature before Jan 6. | Oct 29 |
| Arugula | — | Nov 19–Feb 11 | 427 | two-plantings: Plant Nov 19 and again by Nov 27; both mature before Jan 20. | Nov 27 |
| Brussel Sprouts | Nov 19 | Dec 17–Dec 31 | 399 | fits: 100 days to maturity, 399 available after Dec 17. | Sep 28 |
| Butternut Squash | Dec 31 | Jan 28–Feb 4 | 315 | fits: 100 days to maturity, 315 available after Jan 28. | Aug 17 |
| Eggplant | Nov 26 | Jan 28–Feb 4 | 308 | fits: 70 days to maturity, 308 available after Jan 28. | Sep 9 |
| Okra | Dec 17 | Jan 21–Jan 28 | 329 | two-plantings: Plant Jan 21 and again by Oct 8; both mature before Dec 16. | Oct 8 |
| Basil | Dec 10 | Feb 4–Feb 4 | 315 | two-plantings: Plant Feb 4 and again by Oct 3; both mature before Dec 16. | Oct 3 |
| Cilantro | — | Dec 17–Jan 7 | 385 | two-plantings: Plant Dec 17 and again by Nov 3; both mature before Jan 6. | Nov 3 |
| Parsley | Nov 5 | Jan 21–Jan 28 | 350 | fits: 70 days to maturity, 350 available after Jan 21. | Oct 14 |
| Celery | Nov 5 | Jan 21–Feb 4 | 350 | fits: 120 days to maturity, 350 available after Jan 21. | Aug 25 |
| Scallions | Nov 5 | Dec 17–Dec 31 | 399 | two-plantings: Plant Dec 17 and again by Nov 7; both mature before Jan 20. | Nov 7 |
| Turnip | — | Dec 17–Dec 31 | 399 | two-plantings: Plant Dec 17 and again by Nov 17; both mature before Jan 20. | Nov 17 |
| Kohlrabi | — | Dec 3–Dec 17 | 413 | two-plantings: Plant Dec 3 and again by Nov 12; both mature before Jan 20. | Nov 12 |
| Bok Choy | Dec 17 | Jan 7–Jan 14 | 364 | two-plantings: Plant Jan 7 and again by Nov 8; both mature before Jan 6. | Nov 8 |
| Collards | Nov 5 | Dec 17–Dec 31 | 399 | two-plantings: Plant Dec 17 and again by Nov 7; both mature before Jan 20. | Nov 7 |
| Cantaloupe | Dec 31 | Jan 28–Feb 4 | 308 | fits: 85 days to maturity, 308 available after Jan 28. | Aug 25 |
| Chives | Oct 22 | Jan 21–Jan 28 | 364 | fits: 90 days to maturity, 364 available after Jan 21. | — |
| Dill | — | Nov 19–Feb 11 | 413 | two-plantings: Plant Nov 19 and again by Oct 29; both mature before Jan 6. | Oct 29 |
| Oregano | Nov 5 | Jan 21–Jan 28 | 364 | fits: 80 days to maturity, 364 available after Jan 21. | — |
| Rosemary | Oct 22 | Jan 21–Jan 28 | 350 | fits: 80 days to maturity, 350 available after Jan 21. | — |
| Sage | Nov 19 | Jan 21–Jan 28 | 364 | fits: 75 days to maturity, 364 available after Jan 21. | — |
| Thyme | Nov 5 | Jan 21–Jan 28 | 364 | fits: 90 days to maturity, 364 available after Jan 21. | — |
| Calendula | Dec 3 | Dec 31–Jan 14 | 371 | two-plantings: Plant Dec 31 and again by Nov 3; both mature before Jan 6. | Nov 3 |
| Cosmos | Dec 17 | Jan 14–Jan 28 | 336 | two-plantings: Plant Jan 14 and again by Oct 3; both mature before Dec 16. | Oct 3 |
| Lavender | Oct 22 | Jan 14–Jan 28 | 371 | fits: 90 days to maturity, 371 available after Jan 14. | — |
| Marigolds | Dec 3 | Jan 14–Jan 21 | 336 | two-plantings: Plant Jan 14 and again by Oct 13; both mature before Dec 16. | Oct 13 |
| Melons | Dec 31 | Jan 28–Feb 4 | 308 | fits: 85 days to maturity, 308 available after Jan 28. | Aug 25 |
| Mint | — | Jan 14–Jan 28 | 371 | fits: 90 days to maturity, 371 available after Jan 14. | — |
| Nasturtiums | Dec 17 | Jan 14–Jan 21 | 336 | two-plantings: Plant Jan 14 and again by Oct 8; both mature before Dec 16. | Oct 8 |
| Pole Beans | — | Jan 21–Feb 4 | 329 | fits: 65 days to maturity, 329 available after Jan 21. | Sep 28 |
| Spaghetti Squash | Dec 31 | Jan 28–Feb 4 | 315 | fits: 90 days to maturity, 315 available after Jan 28. | Aug 27 |
| Sunflowers | — | Jan 14–Jan 28 | 336 | fits: 70 days to maturity, 336 available after Jan 14. | Sep 23 |
| Tomatillos | Nov 19 | Jan 21–Jan 28 | 315 | fits: 75 days to maturity, 315 available after Jan 21. | Sep 4 |
| Watermelon | Dec 31 | Jan 21–Jan 28 | 315 | fits: 80 days to maturity, 315 available after Jan 21. | Aug 30 |
| Yellow Squash | Dec 31 | Jan 28–Feb 4 | 322 | two-plantings: Plant Jan 28 and again by Oct 8; both mature before Dec 16. | Oct 8 |
| Zinnias | Dec 17 | Jan 14–Jan 28 | 336 | two-plantings: Plant Jan 14 and again by Oct 3; both mature before Dec 16. | Oct 3 |
Month by month in Alpine
| Month | What to do |
|---|---|
| January | Direct sow from: Sunflowers (Jan 14), Beans (Jan 21), Pole Beans (Jan 21). Transplant from: Bok Choy (Jan 7), Cauliflower (Jan 7), Cosmos (Jan 14), Lavender (Jan 14), Marigolds (Jan 14), Mint (Jan 14), +24 more. Last frost around January 14. Last sowing dates: Garlic (Jan 20). |
| February | Transplant from: Basil (Feb 4). |
| March | Succession plant lettuce and greens. Keep beds weeded and watered consistently. |
| April | Harvest regularly to encourage production. Monitor for pests and disease. |
| May | Midsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall. |
| June | Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors. |
| July | Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors. |
| August | Last sowing dates: Butternut Squash (Aug 17), Pumpkin (Aug 17), Cantaloupe (Aug 25), Celery (Aug 25), Melons (Aug 25), Spaghetti Squash (Aug 27), +2 more. |
| September | Last sowing dates: Pepper (Sep 4), Tomatillos (Sep 4), Eggplant (Sep 9), Corn (Sep 11), Sunflowers (Sep 23), Brussel Sprouts (Sep 28), +1 more. |
| October | Start indoors: Chives (Oct 22), Lavender (Oct 22), Onion (Oct 22), Rosemary (Oct 22). Last sowing dates: Basil (Oct 3), Cosmos (Oct 3), Cucumber (Oct 3), Zinnias (Oct 3), Broccoli (Oct 4), Nasturtiums (Oct 8), +13 more. |
| November | Start indoors: Celery (Nov 5), Collards (Nov 5), Kale (Nov 5), Oregano (Nov 5), Parsley (Nov 5), Scallions (Nov 5), +9 more. Direct sow from: Arugula (Nov 19), Beets (Nov 19), Dill (Nov 19), Peas (Nov 19), Radish (Nov 19), Spinach (Nov 19). Last sowing dates: Calendula (Nov 3), Cilantro (Nov 3), Collards (Nov 7), Scallions (Nov 7), Bok Choy (Nov 8), Lettuce (Nov 8), +6 more. |
| December | Start indoors: Calendula (Dec 3), Cauliflower (Dec 3), Marigolds (Dec 3), Pepper (Dec 3), Basil (Dec 10), Tomato (Dec 10), +15 more. Direct sow from: Kohlrabi (Dec 3), Cilantro (Dec 17), Turnip (Dec 17), Carrots (Dec 24), Garlic (Dec 30), Potatoes (Dec 31). Transplant from: Broccoli (Dec 17), Brussel Sprouts (Dec 17), Cabbage (Dec 17), Collards (Dec 17), Kale (Dec 17), Lettuce (Dec 17), +4 more. Plant: Strawberry (Dec 10). First frost around December 30. |
Frequently Asked Questions
What is the last frost date for Alpine, CA (ZIP 91901)?
The median last spring frost date for Alpine, CA (ZIP code 91901) is around January 14. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.
What is the first fall frost date in Alpine, CA?
The median first fall frost date for Alpine, CA is around December 30. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around November 13 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Alpine, CA?
The frost-free growing season in Alpine is about 350 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Alpine (350 frost-free days, a very long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Alpine, CA?
Alpine, CA is in USDA hardiness zone 9b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Alpine, CA?
Start tomatoes indoors Dec 10 and plant out Jan 28 in Alpine. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Alpine?
Two: plant Dec 17 and again by Nov 8; both mature before Jan 6.
When do I plant garlic in Alpine?
Dec 30 to Jan 20; it overwinters and is ready the following summer.
Can I get two tomato crops in Alpine?
Yes: plant out Jan 28 for a summer crop, and set out a second round of transplants by Aug 30 for a fall crop.
Which nearby ZIP has a longer season?
Spring Valley (ZIP 91977) has 365 frost-free days, 15 more than Alpine (ZIP 91901). See Spring Valley ZIP 91977 frost dates
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