Frost Dates for Harlingen, TX 78550
Last spring frost January 19 · First fall frost January 22 · 3 frost-free days · USDA Zone 10a
ZIP 78550 has about 53,300 people, the largest of 2 ZIP codes in Harlingen.
Short season: 3 frost-free days.
Frost probability for 78550
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | February 19 | January 19 | — |
| Fall (first frost) | December 12 | January 22 | — |
Dates come from NOAA 1971–2000 freeze probabilities at RAYMONDVILLE (26.2 km away); the 50% date is the median year.
Frost dates by ZIP code in Harlingen, TX
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 78550 | January 19 | January 22 | 10a |
| 78552 | January 19 | January 22 | 10a |
Which crops fit a 3-day season in Harlingen
In Harlingen (3 frost-free days, a short season), 7 of 56 planner crops fit outright, 1 get two plantings, 5 need an indoor start, 1 need a faster variety, 41 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Dec 15 | Feb 2–Feb 9 | 0 | no-fit: Needs 80 days; Harlingen has 0 after Feb 2. | — |
| Pepper | Dec 8 | Feb 2–Feb 9 | 0 | no-fit: Needs 75 days; Harlingen has 0 after Feb 2. | — |
| Lettuce | Nov 24 | Dec 22–Dec 29 | 38 | head-start: Even planted out Dec 22, the outdoor season is about 7 days short; choose an early variety or grow under cover. | — |
| Carrots | — | Dec 29–Jan 5 | 45 | no-fit: Needs 70 days; Harlingen has 45 after Dec 29. | — |
| Cucumber | Dec 29 | Feb 2–Feb 9 | 0 | no-fit: Needs 60 days; Harlingen has 0 after Feb 2. | — |
| Beans | — | Jan 26–Feb 9 | 0 | no-fit: Needs 60 days; Harlingen has 0 after Jan 26. | — |
| Peas | — | Nov 24–Feb 2 | 66 | fits: 65 days to maturity, 66 available after Nov 24. | — |
| Zucchini | Jan 5 | Feb 2–Feb 9 | 0 | no-fit: Needs 55 days; Harlingen has 0 after Feb 2. | — |
| Onion | Oct 27 | Dec 22–Jan 5 | 38 | no-fit: Needs 100 days; Harlingen has 38 after Dec 22. | — |
| Spinach | — | Nov 24–Jan 12 | 80 | fits: 40 days to maturity, 80 available after Nov 24. | Dec 20 |
| Kale | Nov 10 | Dec 22–Jan 5 | 52 | head-start: Even planted out Dec 22, the outdoor season is about 3 days short; choose an early variety or grow under cover. | — |
| Broccoli | Nov 24 | Dec 22–Jan 5 | 38 | no-fit: Needs 80 days; Harlingen has 38 after Dec 22. | — |
| Cabbage | Nov 24 | Dec 22–Jan 5 | 52 | head-start: Even planted out Dec 22, the outdoor season is about 18 days short; choose an early variety or grow under cover. | — |
| Radish | — | Nov 24–Feb 16 | 66 | two-plantings: Plant Nov 24 and again by Dec 21; both mature before Jan 29. | Dec 21 |
| Beets | — | Nov 24–Feb 16 | 66 | fits: 55 days to maturity, 66 available after Nov 24. | — |
| Potatoes | — | Jan 5–Jan 12 | 24 | no-fit: Needs 90 days; Harlingen has 24 after Jan 5. | — |
| Garlic | — | Jan 22 | 108 | overwinter: Plant Jan 22 to Feb 12; harvest the following summer. | Feb 12 |
| Strawberry | — | Dec 15–Feb 9 | 59 | 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 | 0 | no-fit: Needs 75 days; Harlingen has 0 after Jan 26. | — |
| Pumpkin | Jan 5 | Feb 2–Feb 2 | 0 | no-fit: Needs 100 days; Harlingen has 0 after Feb 2. | — |
| Cauliflower | Dec 8 | Jan 12–Jan 26 | 17 | no-fit: Needs 75 days; Harlingen has 17 after Jan 12. | — |
| Swiss Chard | Nov 24 | Jan 5–Jan 5 | 24 | no-fit: Needs 55 days; Harlingen has 24 after Jan 5. | — |
| Arugula | — | Nov 24–Feb 16 | 80 | fits: 40 days to maturity, 80 available after Nov 24. | Dec 20 |
| Brussel Sprouts | Nov 24 | Dec 22–Jan 5 | 52 | no-fit: Needs 100 days; Harlingen has 52 after Dec 22. | — |
| Butternut Squash | Jan 5 | Feb 2–Feb 9 | 0 | no-fit: Needs 100 days; Harlingen has 0 after Feb 2. | — |
| Eggplant | Dec 1 | Feb 2–Feb 9 | 0 | no-fit: Needs 70 days; Harlingen has 0 after Feb 2. | — |
| Okra | Dec 22 | Jan 26–Feb 2 | 0 | no-fit: Needs 55 days; Harlingen has 0 after Jan 26. | — |
| Basil | Dec 15 | Feb 9–Feb 9 | 0 | no-fit: Needs 60 days; Harlingen has 0 after Feb 9. | — |
| Cilantro | — | Dec 22–Jan 12 | 38 | tight: Direct-sow only; pick a variety under 38 days. | — |
| Parsley | Nov 10 | Jan 26–Feb 2 | 3 | no-fit: Needs 70 days; Harlingen has 3 after Jan 26. | — |
| Celery | Nov 10 | Jan 26–Feb 9 | 3 | no-fit: Needs 120 days; Harlingen has 3 after Jan 26. | — |
| Scallions | Nov 10 | Dec 22–Jan 5 | 52 | head-start: Even planted out Dec 22, the outdoor season is about 8 days short; choose an early variety or grow under cover. | — |
| Turnip | — | Dec 22–Jan 5 | 52 | fits: 50 days to maturity, 52 available after Dec 22. | — |
| Kohlrabi | — | Dec 8–Dec 22 | 66 | fits: 55 days to maturity, 66 available after Dec 8. | — |
| Bok Choy | Dec 22 | Jan 12–Jan 19 | 17 | no-fit: Needs 45 days; Harlingen has 17 after Jan 12. | — |
| Collards | Nov 10 | Dec 22–Jan 5 | 52 | head-start: Even planted out Dec 22, the outdoor season is about 8 days short; choose an early variety or grow under cover. | — |
| Cantaloupe | Jan 5 | Feb 2–Feb 9 | 0 | no-fit: Needs 85 days; Harlingen has 0 after Feb 2. | — |
| Chives | Oct 27 | Jan 26–Feb 2 | 17 | no-fit: Needs 90 days; Harlingen has 17 after Jan 26. | — |
| Dill | — | Nov 24–Feb 16 | 66 | fits: 55 days to maturity, 66 available after Nov 24. | — |
| Oregano | Nov 10 | Jan 26–Feb 2 | 17 | no-fit: Needs 80 days; Harlingen has 17 after Jan 26. | — |
| Rosemary | Oct 27 | Jan 26–Feb 2 | 3 | no-fit: Needs 80 days; Harlingen has 3 after Jan 26. | — |
| Sage | Nov 24 | Jan 26–Feb 2 | 17 | no-fit: Needs 75 days; Harlingen has 17 after Jan 26. | — |
| Thyme | Nov 10 | Jan 26–Feb 2 | 17 | no-fit: Needs 90 days; Harlingen has 17 after Jan 26. | — |
| Calendula | Dec 8 | Jan 5–Jan 19 | 24 | no-fit: Needs 50 days; Harlingen has 24 after Jan 5. | — |
| Cosmos | Dec 22 | Jan 19–Feb 2 | 0 | no-fit: Needs 60 days; Harlingen has 0 after Jan 19. | — |
| Lavender | Oct 27 | Jan 19–Feb 2 | 24 | no-fit: Needs 90 days; Harlingen has 24 after Jan 19. | — |
| Marigolds | Dec 8 | Jan 19–Jan 26 | 0 | no-fit: Needs 50 days; Harlingen has 0 after Jan 19. | — |
| Melons | Jan 5 | Feb 2–Feb 9 | 0 | no-fit: Needs 85 days; Harlingen has 0 after Feb 2. | — |
| Mint | — | Jan 19–Feb 2 | 24 | no-fit: Needs 90 days; Harlingen has 24 after Jan 19. | — |
| Nasturtiums | Dec 22 | Jan 19–Jan 26 | 0 | no-fit: Needs 55 days; Harlingen has 0 after Jan 19. | — |
| Pole Beans | — | Jan 26–Feb 9 | 0 | no-fit: Needs 65 days; Harlingen has 0 after Jan 26. | — |
| Spaghetti Squash | Jan 5 | Feb 2–Feb 9 | 0 | no-fit: Needs 90 days; Harlingen has 0 after Feb 2. | — |
| Sunflowers | — | Jan 19–Feb 2 | 0 | no-fit: Needs 70 days; Harlingen has 0 after Jan 19. | — |
| Tomatillos | Nov 24 | Jan 26–Feb 2 | 0 | no-fit: Needs 75 days; Harlingen has 0 after Jan 26. | — |
| Watermelon | Jan 5 | Jan 26–Feb 2 | 0 | no-fit: Needs 80 days; Harlingen has 0 after Jan 26. | — |
| Yellow Squash | Jan 5 | Feb 2–Feb 9 | 0 | no-fit: Needs 55 days; Harlingen has 0 after Feb 2. | — |
| Zinnias | Dec 22 | Jan 19–Feb 2 | 0 | no-fit: Needs 60 days; Harlingen has 0 after Jan 19. | — |
Month by month in Harlingen
| 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), Garlic (Jan 22), 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. First frost around January 22. |
| February | Transplant from: Butternut Squash (Feb 2), Cantaloupe (Feb 2), Cucumber (Feb 2), Eggplant (Feb 2), Melons (Feb 2), Pepper (Feb 2), +6 more. Last sowing dates: Garlic (Feb 12). |
| March | Transplant warm-season crops outdoors. Sow beans, cucumbers, and squash. |
| April | Main warm-season planting window. Direct sow melons and sweet corn. |
| May | Succession plant lettuce. Keep beds irrigated as temperatures climb. |
| June | Monitor for heat stress. Harvest zucchini and cucumbers frequently. |
| July | Harvest regularly to encourage continued production. Watch for pests. |
| August | Start fall cool-season crops: broccoli, kale, beets, and carrots. |
| September | Plant fall lettuce, spinach, arugula, and radishes. |
| October | Start indoors: Chives (Oct 27), Lavender (Oct 27), Onion (Oct 27), Rosemary (Oct 27). |
| 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: Arugula (Nov 24), Beets (Nov 24), Dill (Nov 24), Peas (Nov 24), Radish (Nov 24), Spinach (Nov 24). |
| 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: Arugula (Dec 20), Spinach (Dec 20), Radish (Dec 21). |
Frequently Asked Questions
What is the last frost date for Harlingen, TX (ZIP 78550)?
The median last spring frost date for Harlingen, TX (ZIP code 78550) 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 Harlingen, TX?
The median first fall frost date for Harlingen, TX is around January 22. 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 12 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Harlingen, TX?
The frost-free growing season in Harlingen is about 3 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 Harlingen (3 frost-free days, a short season), 7 of 56 planner crops fit outright, 1 get two plantings, 5 need an indoor start, 1 need a faster variety, 41 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Harlingen, TX?
Harlingen, TX 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 Harlingen, TX?
Start tomatoes indoors Dec 15 and plant out Feb 2 in Harlingen. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Harlingen?
One spring planting around Dec 22.
When do I plant garlic in Harlingen?
Jan 22 to Feb 12; it overwinters and is ready the following summer.
Can I grow Celery in Harlingen?
Not reliably outdoors. Needs 120 days; Harlingen has 3 after Jan 26.
Which nearby ZIP has a longer season?
San Benito (ZIP 78586) has 29 frost-free days, 26 more than Harlingen (ZIP 78550). See San Benito ZIP 78586 frost dates
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