Frost Dates for Flagstaff, AZ 86011
Flagstaff has 5 ZIP codes. The Flagstaff, AZ frost page lists all of them with their dates.
Last spring frost June 21 · First fall frost September 9 · 80 frost-free days · USDA Zone 3–4 (est.)
ZIP 86011 has about 4,020 people, one of 5 ZIP codes in Flagstaff.
Short season: 80 frost-free days. Spring frost risk spans June 11–July 2 (21 days). Fall frost risk spans August 20–September 28 (39 days).
Frost probability for 86011
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | July 2 | June 21 | June 11 |
| Fall (first frost) | August 20 | September 9 | September 28 |
Dates come from NOAA 1971–2000 freeze probabilities at SUNSET CRATER NM (22.4 km away); the 50% date is the median year.
Which crops fit a 80-day season in Flagstaff
In Flagstaff (80 frost-free days, a short season), 27 of 56 planner crops fit outright, 10 get two plantings, 4 need an indoor start, 2 need a faster variety, 12 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | May 17 | Jul 5–Jul 12 | 38 | no-fit: Needs 80 days; Flagstaff has 38 after Jul 5. | — |
| Pepper | May 10 | Jul 5–Jul 12 | 38 | no-fit: Needs 75 days; Flagstaff has 38 after Jul 5. | — |
| Lettuce | Apr 26 | May 24–May 31 | 115 | two-plantings: Plant May 24 and again by Jul 19; both mature before Sep 16. | Jul 19 |
| Carrots | — | May 31–Jun 7 | 122 | fits: 70 days to maturity, 122 available after May 31. | Jul 8 |
| Cucumber | May 31 | Jul 5–Jul 12 | 52 | head-start: Even planted out Jul 5, the outdoor season is about 8 days short; choose an early variety or grow under cover. | — |
| Beans | — | Jun 28–Jul 12 | 66 | fits: 60 days to maturity, 66 available after Jun 28. | — |
| Peas | — | Apr 26–Jul 5 | 143 | fits: 65 days to maturity, 143 available after Apr 26. | Jun 29 |
| Zucchini | Jun 7 | Jul 5–Jul 12 | 52 | head-start: Even planted out Jul 5, the outdoor season is about 3 days short; choose an early variety or grow under cover. | — |
| Onion | Mar 29 | May 24–Jun 7 | 115 | fits: 100 days to maturity, 115 available after May 24. | — |
| Spinach | — | Apr 26–Jun 14 | 157 | two-plantings: Plant Apr 26 and again by Aug 7; both mature before Sep 30. | Aug 7 |
| Kale | Apr 12 | May 24–Jun 7 | 129 | two-plantings: Plant May 24 and again by Jul 23; both mature before Sep 30. | Jul 23 |
| Broccoli | Apr 26 | May 24–Jun 7 | 115 | fits: 80 days to maturity, 115 available after May 24. | Jun 14 |
| Cabbage | Apr 26 | May 24–Jun 7 | 129 | fits: 70 days to maturity, 129 available after May 24. | Jul 8 |
| Radish | — | Apr 26–Jul 19 | 143 | two-plantings: Plant Apr 26 and again by Aug 8; both mature before Sep 16. | Aug 8 |
| Beets | — | Apr 26–Jul 19 | 143 | two-plantings: Plant Apr 26 and again by Jul 9; both mature before Sep 16. | Jul 9 |
| Potatoes | — | Jun 7–Jun 14 | 101 | fits: 90 days to maturity, 101 available after Jun 7. | — |
| Garlic | — | Sep 9 | 185 | overwinter: Plant Sep 9 to Sep 30; harvest the following summer. | Sep 30 |
| Strawberry | — | May 17–Jul 12 | 136 | perennial: A perennial: plant May 17; it fruits from the following year and keeps producing for several years. | — |
| Corn | May 24 | Jun 28–Jul 5 | 52 | no-fit: Needs 75 days; Flagstaff has 52 after Jun 28. | — |
| Pumpkin | Jun 7 | Jul 5–Jul 5 | 45 | no-fit: Needs 100 days; Flagstaff has 45 after Jul 5. | — |
| Cauliflower | May 10 | Jun 14–Jun 28 | 94 | fits: 75 days to maturity, 94 available after Jun 14. | Jun 19 |
| Swiss Chard | Apr 26 | Jun 7–Jun 7 | 101 | fits: 55 days to maturity, 101 available after Jun 7. | Jul 9 |
| Arugula | — | Apr 26–Jul 19 | 157 | two-plantings: Plant Apr 26 and again by Aug 7; both mature before Sep 30. | Aug 7 |
| Brussel Sprouts | Apr 26 | May 24–Jun 7 | 129 | fits: 100 days to maturity, 129 available after May 24. | Jun 8 |
| Butternut Squash | Jun 7 | Jul 5–Jul 12 | 45 | no-fit: Needs 100 days; Flagstaff has 45 after Jul 5. | — |
| Eggplant | May 3 | Jul 5–Jul 12 | 38 | no-fit: Needs 70 days; Flagstaff has 38 after Jul 5. | — |
| Okra | May 24 | Jun 28–Jul 5 | 59 | fits: 55 days to maturity, 59 available after Jun 28. | — |
| Basil | May 17 | Jul 12–Jul 12 | 45 | head-start: Even planted out Jul 12, the outdoor season is about 15 days short; choose an early variety or grow under cover. | — |
| Cilantro | — | May 24–Jun 14 | 115 | two-plantings: Plant May 24 and again by Jul 14; both mature before Sep 16. | Jul 14 |
| Parsley | Apr 12 | Jun 28–Jul 5 | 80 | fits: 70 days to maturity, 80 available after Jun 28. | — |
| Celery | Apr 12 | Jun 28–Jul 12 | 80 | no-fit: Needs 120 days; Flagstaff has 80 after Jun 28. | — |
| Scallions | Apr 12 | May 24–Jun 7 | 129 | fits: 60 days to maturity, 129 available after May 24. | Jul 18 |
| Turnip | — | May 24–Jun 7 | 129 | two-plantings: Plant May 24 and again by Jul 28; both mature before Sep 30. | Jul 28 |
| Kohlrabi | — | May 10–May 24 | 143 | two-plantings: Plant May 10 and again by Jul 23; both mature before Sep 30. | Jul 23 |
| Bok Choy | May 24 | Jun 14–Jun 21 | 94 | fits: 45 days to maturity, 94 available after Jun 14. | Jul 19 |
| Collards | Apr 12 | May 24–Jun 7 | 129 | fits: 60 days to maturity, 129 available after May 24. | Jul 18 |
| Cantaloupe | Jun 7 | Jul 5–Jul 12 | 38 | no-fit: Needs 85 days; Flagstaff has 38 after Jul 5. | — |
| Chives | Mar 29 | Jun 28–Jul 5 | 94 | fits: 90 days to maturity, 94 available after Jun 28. | — |
| Dill | — | Apr 26–Jul 19 | 143 | two-plantings: Plant Apr 26 and again by Jul 9; both mature before Sep 16. | Jul 9 |
| Oregano | Apr 12 | Jun 28–Jul 5 | 94 | fits: 80 days to maturity, 94 available after Jun 28. | — |
| Rosemary | Mar 29 | Jun 28–Jul 5 | 80 | fits: 80 days to maturity, 80 available after Jun 28. | — |
| Sage | Apr 26 | Jun 28–Jul 5 | 94 | fits: 75 days to maturity, 94 available after Jun 28. | — |
| Thyme | Apr 12 | Jun 28–Jul 5 | 94 | fits: 90 days to maturity, 94 available after Jun 28. | — |
| Calendula | May 10 | Jun 7–Jun 21 | 101 | fits: 50 days to maturity, 101 available after Jun 7. | Jul 14 |
| Cosmos | May 24 | Jun 21–Jul 5 | 66 | fits: 60 days to maturity, 66 available after Jun 21. | — |
| Lavender | Mar 29 | Jun 21–Jul 5 | 101 | fits: 90 days to maturity, 101 available after Jun 21. | — |
| Marigolds | May 10 | Jun 21–Jun 28 | 66 | fits: 50 days to maturity, 66 available after Jun 21. | Jun 23 |
| Melons | Jun 7 | Jul 5–Jul 12 | 38 | no-fit: Needs 85 days; Flagstaff has 38 after Jul 5. | — |
| Mint | — | Jun 21–Jul 5 | 101 | fits: 90 days to maturity, 101 available after Jun 21. | — |
| Nasturtiums | May 24 | Jun 21–Jun 28 | 66 | fits: 55 days to maturity, 66 available after Jun 21. | — |
| Pole Beans | — | Jun 28–Jul 12 | 59 | tight: Direct-sow only; pick a variety under 59 days. | — |
| Spaghetti Squash | Jun 7 | Jul 5–Jul 12 | 45 | no-fit: Needs 90 days; Flagstaff has 45 after Jul 5. | — |
| Sunflowers | — | Jun 21–Jul 5 | 66 | tight: Direct-sow only; pick a variety under 66 days. | — |
| Tomatillos | Apr 26 | Jun 28–Jul 5 | 45 | no-fit: Needs 75 days; Flagstaff has 45 after Jun 28. | — |
| Watermelon | Jun 7 | Jun 28–Jul 5 | 45 | no-fit: Needs 80 days; Flagstaff has 45 after Jun 28. | — |
| Yellow Squash | Jun 7 | Jul 5–Jul 12 | 52 | head-start: Even planted out Jul 5, the outdoor season is about 3 days short; choose an early variety or grow under cover. | — |
| Zinnias | May 24 | Jun 21–Jul 5 | 66 | fits: 60 days to maturity, 66 available after Jun 21. | — |
Month by month in Flagstaff
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start the slowest-growing crops indoors: onions, leeks, and celery (10–12 weeks before last frost). |
| March | Start indoors: Chives (Mar 29), Lavender (Mar 29), Onion (Mar 29), Rosemary (Mar 29). |
| April | Start indoors: Celery (Apr 12), Collards (Apr 12), Kale (Apr 12), Oregano (Apr 12), Parsley (Apr 12), Scallions (Apr 12), +8 more. Direct sow from: Arugula (Apr 26), Beets (Apr 26), Dill (Apr 26), Peas (Apr 26), Radish (Apr 26), Spinach (Apr 26). |
| May | Start indoors: Eggplant (May 3), Calendula (May 10), Cauliflower (May 10), Marigolds (May 10), Pepper (May 10), Basil (May 17), +8 more. Direct sow from: Kohlrabi (May 10), Cilantro (May 24), Turnip (May 24), Carrots (May 31). Transplant from: Broccoli (May 24), Brussel Sprouts (May 24), Cabbage (May 24), Collards (May 24), Kale (May 24), Lettuce (May 24), +2 more. Plant: Strawberry (May 17). |
| June | Start indoors: Butternut Squash (Jun 7), Cantaloupe (Jun 7), Melons (Jun 7), Pumpkin (Jun 7), Spaghetti Squash (Jun 7), Watermelon (Jun 7), +2 more. Direct sow from: Potatoes (Jun 7), Sunflowers (Jun 21), Beans (Jun 28), Pole Beans (Jun 28). Transplant from: Calendula (Jun 7), Swiss Chard (Jun 7), Bok Choy (Jun 14), Cauliflower (Jun 14), Cosmos (Jun 21), Lavender (Jun 21), +15 more. Last frost around June 21. Last sowing dates: Brussel Sprouts (Jun 8), Broccoli (Jun 14), Cauliflower (Jun 19), Marigolds (Jun 23), Peas (Jun 29). |
| July | Transplant from: Butternut Squash (Jul 5), Cantaloupe (Jul 5), Cucumber (Jul 5), Eggplant (Jul 5), Melons (Jul 5), Pepper (Jul 5), +6 more. Last sowing dates: Cabbage (Jul 8), Carrots (Jul 8), Beets (Jul 9), Dill (Jul 9), Swiss Chard (Jul 9), Calendula (Jul 14), +8 more. |
| August | Last sowing dates: Arugula (Aug 7), Spinach (Aug 7), Radish (Aug 8). |
| September | Direct sow from: Garlic (Sep 9). First frost around September 9. Last sowing dates: Garlic (Sep 30). |
| October | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
| November | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Flagstaff, AZ (ZIP 86011)?
The median last spring frost date for Flagstaff, AZ (ZIP code 86011) is around June 21. 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. One year in ten frost ends before June 11; one in ten it runs past July 2.
What is the first fall frost date in Flagstaff, AZ?
The median first fall frost date for Flagstaff, AZ is around September 9. 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 August 20 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Flagstaff, AZ?
The frost-free growing season in Flagstaff is about 80 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 Flagstaff (80 frost-free days, a short season), 27 of 56 planner crops fit outright, 10 get two plantings, 4 need an indoor start, 2 need a faster variety, 12 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Flagstaff, AZ?
Flagstaff, AZ is approximately in USDA zone 3–4. The 2023 USDA map does not list ZIP 86011, so this is estimated from local frost patterns; check the USDA map for your exact address.
When should I start tomatoes indoors in Flagstaff, AZ?
Start tomatoes indoors May 17 and plant out Jul 5 in Flagstaff. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Flagstaff?
Two: plant May 24 and again by Jul 19; both mature before Sep 16.
When do I plant garlic in Flagstaff?
Sep 9 to Sep 30; it overwinters and is ready the following summer.
Can I grow Celery in Flagstaff?
Not reliably outdoors. Needs 120 days; Flagstaff has 80 after Jun 28.
Which nearby ZIP has a longer season?
Sedona (ZIP 86336) has 199 frost-free days, 119 more than Flagstaff (ZIP 86011). See Sedona ZIP 86336 frost dates
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