Frost Dates for Flagstaff, AZ 86004
Flagstaff has 5 ZIP codes. The Flagstaff, AZ frost page lists all of them with their dates.
Last spring frost June 9 · First fall frost September 22 · 105 frost-free days · USDA Zone 6b
ZIP 86004 has about 36,400 people, one of 5 ZIP codes in Flagstaff.
Short season: 105 frost-free days. Spring frost risk spans May 27–June 23 (27 days). Fall frost risk spans September 11–October 4 (23 days).
Frost probability for 86004
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 23 | June 9 | May 27 |
| Fall (first frost) | September 11 | September 22 | October 4 |
Dates come from NOAA 1971–2000 freeze probabilities at FLAGSTAFF AP (36.9 km away); the 50% date is the median year.
Which crops fit a 105-day season in Flagstaff
In Flagstaff (105 frost-free days, a short season), 29 of 56 planner crops fit outright, 15 get two plantings, 7 need an indoor start, 4 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | May 5 | Jun 23–Jun 30 | 63 | head-start: Even planted out Jun 23, the outdoor season is about 17 days short; choose an early variety or grow under cover. | — |
| Pepper | Apr 28 | Jun 23–Jun 30 | 63 | head-start: Even planted out Jun 23, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Lettuce | Apr 14 | May 12–May 19 | 140 | two-plantings: Plant May 12 and again by Aug 1; both mature before Sep 29. | Aug 1 |
| Carrots | — | May 19–May 26 | 147 | fits: 70 days to maturity, 147 available after May 19. | Jul 21 |
| Cucumber | May 19 | Jun 23–Jun 30 | 77 | fits: 60 days to maturity, 77 available after Jun 23. | Jun 26 |
| Beans | — | Jun 16–Jun 30 | 91 | fits: 60 days to maturity, 91 available after Jun 16. | Jul 3 |
| Peas | — | Apr 14–Jun 23 | 168 | fits: 65 days to maturity, 168 available after Apr 14. | Jul 12 |
| Zucchini | May 26 | Jun 23–Jun 30 | 77 | fits: 55 days to maturity, 77 available after Jun 23. | Jul 1 |
| Onion | Mar 17 | May 12–May 26 | 140 | fits: 100 days to maturity, 140 available after May 12. | — |
| Spinach | — | Apr 14–Jun 2 | 182 | two-plantings: Plant Apr 14 and again by Aug 20; both mature before Oct 13. | Aug 20 |
| Kale | Mar 31 | May 12–May 26 | 154 | two-plantings: Plant May 12 and again by Aug 5; both mature before Oct 13. | Aug 5 |
| Broccoli | Apr 14 | May 12–May 26 | 140 | fits: 80 days to maturity, 140 available after May 12. | Jun 27 |
| Cabbage | Apr 14 | May 12–May 26 | 154 | fits: 70 days to maturity, 154 available after May 12. | Jul 21 |
| Radish | — | Apr 14–Jul 7 | 168 | two-plantings: Plant Apr 14 and again by Aug 21; both mature before Sep 29. | Aug 21 |
| Beets | — | Apr 14–Jul 7 | 168 | two-plantings: Plant Apr 14 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Potatoes | — | May 26–Jun 2 | 126 | fits: 90 days to maturity, 126 available after May 26. | — |
| Garlic | — | Sep 22 | 210 | overwinter: Plant Sep 22 to Oct 13; harvest the following summer. | Oct 13 |
| Strawberry | — | May 5–Jun 30 | 161 | perennial: A perennial: plant May 5; it fruits from the following year and keeps producing for several years. | — |
| Corn | May 12 | Jun 16–Jun 23 | 77 | fits: 75 days to maturity, 77 available after Jun 16. | — |
| Pumpkin | May 26 | Jun 23–Jun 23 | 70 | no-fit: Needs 100 days; Flagstaff has 70 after Jun 23. | — |
| Cauliflower | Apr 28 | Jun 2–Jun 16 | 119 | fits: 75 days to maturity, 119 available after Jun 2. | Jul 2 |
| Swiss Chard | Apr 14 | May 26–May 26 | 126 | two-plantings: Plant May 26 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Arugula | — | Apr 14–Jul 7 | 182 | two-plantings: Plant Apr 14 and again by Aug 20; both mature before Oct 13. | Aug 20 |
| Brussel Sprouts | Apr 14 | May 12–May 26 | 154 | fits: 100 days to maturity, 154 available after May 12. | Jun 21 |
| Butternut Squash | May 26 | Jun 23–Jun 30 | 70 | no-fit: Needs 100 days; Flagstaff has 70 after Jun 23. | — |
| Eggplant | Apr 21 | Jun 23–Jun 30 | 63 | head-start: Even planted out Jun 23, the outdoor season is about 7 days short; choose an early variety or grow under cover. | — |
| Okra | May 12 | Jun 16–Jun 23 | 84 | fits: 55 days to maturity, 84 available after Jun 16. | Jul 1 |
| Basil | May 5 | Jun 30–Jun 30 | 70 | fits: 60 days to maturity, 70 available after Jun 30. | — |
| Cilantro | — | May 12–Jun 2 | 140 | two-plantings: Plant May 12 and again by Jul 27; both mature before Sep 29. | Jul 27 |
| Parsley | Mar 31 | Jun 16–Jun 23 | 105 | fits: 70 days to maturity, 105 available after Jun 16. | Jul 7 |
| Celery | Mar 31 | Jun 16–Jun 30 | 105 | head-start: Even planted out Jun 16, the outdoor season is about 15 days short; choose an early variety or grow under cover. | — |
| Scallions | Mar 31 | May 12–May 26 | 154 | two-plantings: Plant May 12 and again by Jul 31; both mature before Oct 13. | Jul 31 |
| Turnip | — | May 12–May 26 | 154 | two-plantings: Plant May 12 and again by Aug 10; both mature before Oct 13. | Aug 10 |
| Kohlrabi | — | Apr 28–May 12 | 168 | two-plantings: Plant Apr 28 and again by Aug 5; both mature before Oct 13. | Aug 5 |
| Bok Choy | May 12 | Jun 2–Jun 9 | 119 | two-plantings: Plant Jun 2 and again by Aug 1; both mature before Sep 29. | Aug 1 |
| Collards | Mar 31 | May 12–May 26 | 154 | two-plantings: Plant May 12 and again by Jul 31; both mature before Oct 13. | Jul 31 |
| Cantaloupe | May 26 | Jun 23–Jun 30 | 63 | no-fit: Needs 85 days; Flagstaff has 63 after Jun 23. | — |
| Chives | Mar 17 | Jun 16–Jun 23 | 119 | fits: 90 days to maturity, 119 available after Jun 16. | — |
| Dill | — | Apr 14–Jul 7 | 168 | two-plantings: Plant Apr 14 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Oregano | Mar 31 | Jun 16–Jun 23 | 119 | fits: 80 days to maturity, 119 available after Jun 16. | — |
| Rosemary | Mar 17 | Jun 16–Jun 23 | 105 | fits: 80 days to maturity, 105 available after Jun 16. | — |
| Sage | Apr 14 | Jun 16–Jun 23 | 119 | fits: 75 days to maturity, 119 available after Jun 16. | — |
| Thyme | Mar 31 | Jun 16–Jun 23 | 119 | fits: 90 days to maturity, 119 available after Jun 16. | — |
| Calendula | Apr 28 | May 26–Jun 9 | 126 | two-plantings: Plant May 26 and again by Jul 27; both mature before Sep 29. | Jul 27 |
| Cosmos | May 12 | Jun 9–Jun 23 | 91 | fits: 60 days to maturity, 91 available after Jun 9. | Jun 26 |
| Lavender | Mar 17 | Jun 9–Jun 23 | 126 | fits: 90 days to maturity, 126 available after Jun 9. | — |
| Marigolds | Apr 28 | Jun 9–Jun 16 | 91 | fits: 50 days to maturity, 91 available after Jun 9. | Jul 6 |
| Melons | May 26 | Jun 23–Jun 30 | 63 | no-fit: Needs 85 days; Flagstaff has 63 after Jun 23. | — |
| Mint | — | Jun 9–Jun 23 | 126 | fits: 90 days to maturity, 126 available after Jun 9. | — |
| Nasturtiums | May 12 | Jun 9–Jun 16 | 91 | fits: 55 days to maturity, 91 available after Jun 9. | Jul 1 |
| Pole Beans | — | Jun 16–Jun 30 | 84 | fits: 65 days to maturity, 84 available after Jun 16. | Jun 21 |
| Spaghetti Squash | May 26 | Jun 23–Jun 30 | 70 | head-start: Even planted out Jun 23, the outdoor season is about 20 days short; choose an early variety or grow under cover. | — |
| Sunflowers | — | Jun 9–Jun 23 | 91 | fits: 70 days to maturity, 91 available after Jun 9. | Jun 16 |
| Tomatillos | Apr 14 | Jun 16–Jun 23 | 70 | head-start: Even planted out Jun 16, the outdoor season is about 5 days short; choose an early variety or grow under cover. | — |
| Watermelon | May 26 | Jun 16–Jun 23 | 70 | head-start: Even planted out Jun 16, the outdoor season is about 10 days short; choose an early variety or grow under cover. | — |
| Yellow Squash | May 26 | Jun 23–Jun 30 | 77 | fits: 55 days to maturity, 77 available after Jun 23. | Jul 1 |
| Zinnias | May 12 | Jun 9–Jun 23 | 91 | fits: 60 days to maturity, 91 available after Jun 9. | Jun 26 |
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 17), Lavender (Mar 17), Onion (Mar 17), Rosemary (Mar 17), Celery (Mar 31), Collards (Mar 31), +5 more. |
| April | Start indoors: Broccoli (Apr 14), Brussel Sprouts (Apr 14), Cabbage (Apr 14), Lettuce (Apr 14), Sage (Apr 14), Swiss Chard (Apr 14), +6 more. Direct sow from: Arugula (Apr 14), Beets (Apr 14), Dill (Apr 14), Peas (Apr 14), Radish (Apr 14), Spinach (Apr 14), +1 more. |
| May | Start indoors: Basil (May 5), Tomato (May 5), Bok Choy (May 12), Corn (May 12), Cosmos (May 12), Nasturtiums (May 12), +11 more. Direct sow from: Cilantro (May 12), Turnip (May 12), Carrots (May 19), Potatoes (May 26). Transplant from: Broccoli (May 12), Brussel Sprouts (May 12), Cabbage (May 12), Collards (May 12), Kale (May 12), Lettuce (May 12), +4 more. Plant: Strawberry (May 5). |
| June | Direct sow from: Sunflowers (Jun 9), Beans (Jun 16), Pole Beans (Jun 16). Transplant from: Bok Choy (Jun 2), Cauliflower (Jun 2), Cosmos (Jun 9), Lavender (Jun 9), Marigolds (Jun 9), Mint (Jun 9), +25 more. Last frost around June 9. Last sowing dates: Sunflowers (Jun 16), Brussel Sprouts (Jun 21), Pole Beans (Jun 21), Cosmos (Jun 26), Cucumber (Jun 26), Zinnias (Jun 26), +1 more. |
| July | Last sowing dates: Nasturtiums (Jul 1), Okra (Jul 1), Yellow Squash (Jul 1), Zucchini (Jul 1), Cauliflower (Jul 2), Beans (Jul 3), +12 more. |
| August | Last sowing dates: Bok Choy (Aug 1), Lettuce (Aug 1), Kale (Aug 5), Kohlrabi (Aug 5), Turnip (Aug 10), Arugula (Aug 20), +2 more. |
| September | Direct sow from: Garlic (Sep 22). First frost around September 22. |
| October | Last sowing dates: Garlic (Oct 13). |
| 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 86004)?
The median last spring frost date for Flagstaff, AZ (ZIP code 86004) is around June 9. 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 May 27; one in ten it runs past June 23.
What is the first fall frost date in Flagstaff, AZ?
The median first fall frost date for Flagstaff, AZ is around September 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 September 11 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 105 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 (105 frost-free days, a short season), 29 of 56 planner crops fit outright, 15 get two plantings, 7 need an indoor start, 4 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Flagstaff, AZ?
Flagstaff, AZ is in USDA hardiness zone 6b (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 Flagstaff, AZ?
Start tomatoes indoors May 5 and plant out Jun 23 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 12 and again by Aug 1; both mature before Sep 29.
When do I plant garlic in Flagstaff?
Sep 22 to Oct 13; it overwinters and is ready the following summer.
Can I grow Celery in Flagstaff?
Yes, with help. Even planted out Jun 16, the outdoor season is about 15 days short; choose an early variety or grow under cover.
Which nearby ZIP has a longer season?
Sedona (ZIP 86336) has 199 frost-free days, 94 more than Flagstaff (ZIP 86004). See Sedona ZIP 86336 frost dates
Nearby and related
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