Frost Dates for Glendora, CA 91740
Last spring frost January 19 · First fall frost November 17 · 302 frost-free days · USDA Zone 10a
ZIP 91740 has about 26,200 people, the largest of 2 ZIP codes in Glendora.
Very long season: 302 frost-free days.
Frost probability for 91740
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | March 5 | January 19 | — |
| Fall (first frost) | December 1 | November 17 | — |
Dates come from NOAA 1971–2000 freeze probabilities at POMONA/FAIRPLEX (9.1 km away); the 50% date is the median year.
Frost dates by ZIP code in Glendora, CA
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 91740 | January 19 | November 17 | 10a |
| 91741 | January 19 | November 17 | 10a |
Which crops fit a 302-day season in Glendora
In Glendora (302 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 15 | Feb 2–Feb 9 | 260 | fits: 80 days to maturity, 260 available after Feb 2. | Jul 18 |
| Pepper | Dec 8 | Feb 2–Feb 9 | 260 | fits: 75 days to maturity, 260 available after Feb 2. | Jul 23 |
| Lettuce | Nov 24 | Dec 22–Dec 29 | 337 | two-plantings: Plant Dec 22 and again by Sep 26; both mature before Nov 24. | Sep 26 |
| Carrots | — | Dec 29–Jan 5 | 344 | fits: 70 days to maturity, 344 available after Dec 29. | Sep 15 |
| Cucumber | Dec 29 | Feb 2–Feb 9 | 274 | two-plantings: Plant Feb 2 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Beans | — | Jan 26–Feb 9 | 288 | two-plantings: Plant Jan 26 and again by Aug 28; both mature before Nov 10. | Aug 28 |
| Peas | — | Nov 24–Feb 2 | 365 | fits: 65 days to maturity, 365 available after Nov 24. | Sep 6 |
| Zucchini | Jan 5 | Feb 2–Feb 9 | 274 | two-plantings: Plant Feb 2 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Onion | Oct 27 | Dec 22–Jan 5 | 337 | fits: 100 days to maturity, 337 available after Dec 22. | — |
| Spinach | — | Nov 24–Jan 12 | 379 | two-plantings: Plant Nov 24 and again by Oct 15; both mature before Dec 8. | Oct 15 |
| Kale | Nov 10 | Dec 22–Jan 5 | 351 | two-plantings: Plant Dec 22 and again by Sep 30; both mature before Dec 8. | Sep 30 |
| Broccoli | Nov 24 | Dec 22–Jan 5 | 337 | fits: 80 days to maturity, 337 available after Dec 22. | Aug 22 |
| Cabbage | Nov 24 | Dec 22–Jan 5 | 351 | fits: 70 days to maturity, 351 available after Dec 22. | Sep 15 |
| Radish | — | Nov 24–Feb 16 | 365 | two-plantings: Plant Nov 24 and again by Oct 16; both mature before Nov 24. | Oct 16 |
| Beets | — | Nov 24–Feb 16 | 365 | two-plantings: Plant Nov 24 and again by Sep 16; both mature before Nov 24. | Sep 16 |
| Potatoes | — | Jan 5–Jan 12 | 323 | fits: 90 days to maturity, 323 available after Jan 5. | — |
| Garlic | — | Nov 17 | 407 | overwinter: Plant Nov 17 to Dec 8; harvest the following summer. | Dec 8 |
| Strawberry | — | Dec 15–Feb 9 | 358 | perennial: A perennial: plant Dec 15; it fruits from the following year and keeps producing for several years. | — |
| Corn | Dec 22 | Jan 26–Feb 2 | 274 | fits: 75 days to maturity, 274 available after Jan 26. | Jul 30 |
| Pumpkin | Jan 5 | Feb 2–Feb 2 | 267 | fits: 100 days to maturity, 267 available after Feb 2. | Jul 5 |
| Cauliflower | Dec 8 | Jan 12–Jan 26 | 316 | fits: 75 days to maturity, 316 available after Jan 12. | Aug 27 |
| Swiss Chard | Nov 24 | Jan 5–Jan 5 | 323 | two-plantings: Plant Jan 5 and again by Sep 16; both mature before Nov 24. | Sep 16 |
| Arugula | — | Nov 24–Feb 16 | 379 | two-plantings: Plant Nov 24 and again by Oct 15; both mature before Dec 8. | Oct 15 |
| Brussel Sprouts | Nov 24 | Dec 22–Jan 5 | 351 | fits: 100 days to maturity, 351 available after Dec 22. | Aug 16 |
| Butternut Squash | Jan 5 | Feb 2–Feb 9 | 267 | fits: 100 days to maturity, 267 available after Feb 2. | Jul 5 |
| Eggplant | Dec 1 | Feb 2–Feb 9 | 260 | fits: 70 days to maturity, 260 available after Feb 2. | Jul 28 |
| Okra | Dec 22 | Jan 26–Feb 2 | 281 | two-plantings: Plant Jan 26 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Basil | Dec 15 | Feb 9–Feb 9 | 267 | two-plantings: Plant Feb 9 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Cilantro | — | Dec 22–Jan 12 | 337 | two-plantings: Plant Dec 22 and again by Sep 21; both mature before Nov 24. | Sep 21 |
| Parsley | Nov 10 | Jan 26–Feb 2 | 302 | fits: 70 days to maturity, 302 available after Jan 26. | Sep 1 |
| Celery | Nov 10 | Jan 26–Feb 9 | 302 | fits: 120 days to maturity, 302 available after Jan 26. | Jul 13 |
| Scallions | Nov 10 | Dec 22–Jan 5 | 351 | two-plantings: Plant Dec 22 and again by Sep 25; both mature before Dec 8. | Sep 25 |
| Turnip | — | Dec 22–Jan 5 | 351 | two-plantings: Plant Dec 22 and again by Oct 5; both mature before Dec 8. | Oct 5 |
| Kohlrabi | — | Dec 8–Dec 22 | 365 | two-plantings: Plant Dec 8 and again by Sep 30; both mature before Dec 8. | Sep 30 |
| Bok Choy | Dec 22 | Jan 12–Jan 19 | 316 | two-plantings: Plant Jan 12 and again by Sep 26; both mature before Nov 24. | Sep 26 |
| Collards | Nov 10 | Dec 22–Jan 5 | 351 | two-plantings: Plant Dec 22 and again by Sep 25; both mature before Dec 8. | Sep 25 |
| Cantaloupe | Jan 5 | Feb 2–Feb 9 | 260 | fits: 85 days to maturity, 260 available after Feb 2. | Jul 13 |
| Chives | Oct 27 | Jan 26–Feb 2 | 316 | fits: 90 days to maturity, 316 available after Jan 26. | — |
| Dill | — | Nov 24–Feb 16 | 365 | two-plantings: Plant Nov 24 and again by Sep 16; both mature before Nov 24. | Sep 16 |
| Oregano | Nov 10 | Jan 26–Feb 2 | 316 | fits: 80 days to maturity, 316 available after Jan 26. | — |
| Rosemary | Oct 27 | Jan 26–Feb 2 | 302 | fits: 80 days to maturity, 302 available after Jan 26. | — |
| Sage | Nov 24 | Jan 26–Feb 2 | 316 | fits: 75 days to maturity, 316 available after Jan 26. | — |
| Thyme | Nov 10 | Jan 26–Feb 2 | 316 | fits: 90 days to maturity, 316 available after Jan 26. | — |
| Calendula | Dec 8 | Jan 5–Jan 19 | 323 | two-plantings: Plant Jan 5 and again by Sep 21; both mature before Nov 24. | Sep 21 |
| Cosmos | Dec 22 | Jan 19–Feb 2 | 288 | two-plantings: Plant Jan 19 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Lavender | Oct 27 | Jan 19–Feb 2 | 323 | fits: 90 days to maturity, 323 available after Jan 19. | — |
| Marigolds | Dec 8 | Jan 19–Jan 26 | 288 | two-plantings: Plant Jan 19 and again by Aug 31; both mature before Nov 3. | Aug 31 |
| Melons | Jan 5 | Feb 2–Feb 9 | 260 | fits: 85 days to maturity, 260 available after Feb 2. | Jul 13 |
| Mint | — | Jan 19–Feb 2 | 323 | fits: 90 days to maturity, 323 available after Jan 19. | — |
| Nasturtiums | Dec 22 | Jan 19–Jan 26 | 288 | two-plantings: Plant Jan 19 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Pole Beans | — | Jan 26–Feb 9 | 281 | fits: 65 days to maturity, 281 available after Jan 26. | Aug 16 |
| Spaghetti Squash | Jan 5 | Feb 2–Feb 9 | 267 | fits: 90 days to maturity, 267 available after Feb 2. | Jul 15 |
| Sunflowers | — | Jan 19–Feb 2 | 288 | fits: 70 days to maturity, 288 available after Jan 19. | Aug 11 |
| Tomatillos | Nov 24 | Jan 26–Feb 2 | 267 | fits: 75 days to maturity, 267 available after Jan 26. | Jul 23 |
| Watermelon | Jan 5 | Jan 26–Feb 2 | 267 | fits: 80 days to maturity, 267 available after Jan 26. | Jul 18 |
| Yellow Squash | Jan 5 | Feb 2–Feb 9 | 274 | two-plantings: Plant Feb 2 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Zinnias | Dec 22 | Jan 19–Feb 2 | 288 | two-plantings: Plant Jan 19 and again by Aug 21; both mature before Nov 3. | Aug 21 |
Month by month in Glendora
| Month | What to do |
|---|---|
| January | Start indoors: Butternut Squash (Jan 5), Cantaloupe (Jan 5), Melons (Jan 5), Pumpkin (Jan 5), Spaghetti Squash (Jan 5), Watermelon (Jan 5), +2 more. Direct sow from: Potatoes (Jan 5), Sunflowers (Jan 19), Beans (Jan 26), Pole Beans (Jan 26). Transplant from: Calendula (Jan 5), Swiss Chard (Jan 5), Bok Choy (Jan 12), Cauliflower (Jan 12), Cosmos (Jan 19), Lavender (Jan 19), +15 more. Last frost around January 19. |
| February | Transplant from: Butternut Squash (Feb 2), Cantaloupe (Feb 2), Cucumber (Feb 2), Eggplant (Feb 2), Melons (Feb 2), Pepper (Feb 2), +6 more. |
| 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 | Last sowing dates: Butternut Squash (Jul 5), Pumpkin (Jul 5), Cantaloupe (Jul 13), Celery (Jul 13), Melons (Jul 13), Spaghetti Squash (Jul 15), +6 more. |
| August | Last sowing dates: Sunflowers (Aug 11), Brussel Sprouts (Aug 16), Pole Beans (Aug 16), Basil (Aug 21), Cosmos (Aug 21), Cucumber (Aug 21), +9 more. |
| September | Last sowing dates: Parsley (Sep 1), Peas (Sep 6), Cabbage (Sep 15), Carrots (Sep 15), Beets (Sep 16), Dill (Sep 16), +9 more. |
| October | Start indoors: Chives (Oct 27), Lavender (Oct 27), Onion (Oct 27), Rosemary (Oct 27). Last sowing dates: Turnip (Oct 5), Arugula (Oct 15), Spinach (Oct 15), Radish (Oct 16). |
| November | Start indoors: Celery (Nov 10), Collards (Nov 10), Kale (Nov 10), Oregano (Nov 10), Parsley (Nov 10), Scallions (Nov 10), +8 more. Direct sow from: Garlic (Nov 17), Arugula (Nov 24), Beets (Nov 24), Dill (Nov 24), Peas (Nov 24), Radish (Nov 24), +1 more. First frost around November 17. |
| December | Start indoors: Eggplant (Dec 1), Calendula (Dec 8), Cauliflower (Dec 8), Marigolds (Dec 8), Pepper (Dec 8), Basil (Dec 15), +8 more. Direct sow from: Kohlrabi (Dec 8), Cilantro (Dec 22), Turnip (Dec 22), Carrots (Dec 29). Transplant from: Broccoli (Dec 22), Brussel Sprouts (Dec 22), Cabbage (Dec 22), Collards (Dec 22), Kale (Dec 22), Lettuce (Dec 22), +2 more. Plant: Strawberry (Dec 15). Last sowing dates: Garlic (Dec 8). |
Frequently Asked Questions
What is the last frost date for Glendora, CA (ZIP 91740)?
The median last spring frost date for Glendora, CA (ZIP code 91740) is around January 19. 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 Glendora, CA?
The median first fall frost date for Glendora, CA is around November 17. 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 December 1 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Glendora, CA?
The frost-free growing season in Glendora is about 302 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 Glendora (302 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 Glendora, CA?
Glendora, CA is in USDA hardiness zone 10a (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 Glendora, CA?
Start tomatoes indoors Dec 15 and plant out Feb 2 in Glendora. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Glendora?
Two: plant Dec 22 and again by Sep 26; both mature before Nov 24.
When do I plant garlic in Glendora?
Nov 17 to Dec 8; it overwinters and is ready the following summer.
Can I get two tomato crops in Glendora?
Yes: plant out Feb 2 for a summer crop, and set out a second round of transplants by Jul 18 for a fall crop.
Which nearby ZIP has a longer season?
Duarte (ZIP 91010) has 359 frost-free days, 57 more than Glendora (ZIP 91740). See Duarte ZIP 91010 frost dates
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