Frost Dates for Choteau, MT 59422
Last spring frost May 27 · First fall frost September 12 · 108 frost-free days · USDA Zone 4b
ZIP 59422 has about 2,940 people.
Short season: 108 frost-free days. Spring frost risk spans May 13–June 9 (27 days). Fall frost risk spans September 2–September 22 (20 days).
Frost probability for 59422
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 9 | May 27 | May 13 |
| Fall (first frost) | September 2 | September 12 | September 22 |
Dates come from NOAA 1971–2000 freeze probabilities at AUGUSTA (39.1 km away); the 50% date is the median year.
Which crops fit a 108-day season in Choteau
In Choteau (108 frost-free days, a short season), 29 of 56 planner crops fit outright, 15 get two plantings, 9 need an indoor start, 2 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 22 | Jun 10–Jun 17 | 66 | head-start: Even planted out Jun 10, the outdoor season is about 14 days short; choose an early variety or grow under cover. | — |
| Pepper | Apr 15 | Jun 10–Jun 17 | 66 | head-start: Even planted out Jun 10, the outdoor season is about 9 days short; choose an early variety or grow under cover. | — |
| Lettuce | Apr 1 | Apr 29–May 6 | 143 | two-plantings: Plant Apr 29 and again by Jul 22; both mature before Sep 19. | Jul 22 |
| Carrots | — | May 6–May 13 | 150 | fits: 70 days to maturity, 150 available after May 6. | Jul 11 |
| Cucumber | May 6 | Jun 10–Jun 17 | 80 | fits: 60 days to maturity, 80 available after Jun 10. | Jun 16 |
| Beans | — | Jun 3–Jun 17 | 94 | fits: 60 days to maturity, 94 available after Jun 3. | Jun 23 |
| Peas | — | Apr 1–Jun 10 | 171 | fits: 65 days to maturity, 171 available after Apr 1. | Jul 2 |
| Zucchini | May 13 | Jun 10–Jun 17 | 80 | fits: 55 days to maturity, 80 available after Jun 10. | Jun 21 |
| Onion | Mar 4 | Apr 29–May 13 | 143 | fits: 100 days to maturity, 143 available after Apr 29. | — |
| Spinach | — | Apr 1–May 20 | 185 | two-plantings: Plant Apr 1 and again by Aug 10; both mature before Oct 3. | Aug 10 |
| Kale | Mar 18 | Apr 29–May 13 | 157 | two-plantings: Plant Apr 29 and again by Jul 26; both mature before Oct 3. | Jul 26 |
| Broccoli | Apr 1 | Apr 29–May 13 | 143 | fits: 80 days to maturity, 143 available after Apr 29. | Jun 17 |
| Cabbage | Apr 1 | Apr 29–May 13 | 157 | fits: 70 days to maturity, 157 available after Apr 29. | Jul 11 |
| Radish | — | Apr 1–Jun 24 | 171 | two-plantings: Plant Apr 1 and again by Aug 11; both mature before Sep 19. | Aug 11 |
| Beets | — | Apr 1–Jun 24 | 171 | two-plantings: Plant Apr 1 and again by Jul 12; both mature before Sep 19. | Jul 12 |
| Potatoes | — | May 13–May 20 | 129 | fits: 90 days to maturity, 129 available after May 13. | — |
| Garlic | — | Sep 12 | 213 | overwinter: Plant Sep 12 to Oct 3; harvest the following summer. | Oct 3 |
| Strawberry | — | Apr 22–Jun 17 | 164 | perennial: A perennial: plant Apr 22; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 29 | Jun 3–Jun 10 | 80 | fits: 75 days to maturity, 80 available after Jun 3. | — |
| Pumpkin | May 13 | Jun 10–Jun 10 | 73 | no-fit: Needs 100 days; Choteau has 73 after Jun 10. | — |
| Cauliflower | Apr 15 | May 20–Jun 3 | 122 | fits: 75 days to maturity, 122 available after May 20. | Jun 22 |
| Swiss Chard | Apr 1 | May 13–May 13 | 129 | two-plantings: Plant May 13 and again by Jul 12; both mature before Sep 19. | Jul 12 |
| Arugula | — | Apr 1–Jun 24 | 185 | two-plantings: Plant Apr 1 and again by Aug 10; both mature before Oct 3. | Aug 10 |
| Brussel Sprouts | Apr 1 | Apr 29–May 13 | 157 | fits: 100 days to maturity, 157 available after Apr 29. | Jun 11 |
| Butternut Squash | May 13 | Jun 10–Jun 17 | 73 | no-fit: Needs 100 days; Choteau has 73 after Jun 10. | — |
| Eggplant | Apr 8 | Jun 10–Jun 17 | 66 | head-start: Even planted out Jun 10, the outdoor season is about 4 days short; choose an early variety or grow under cover. | — |
| Okra | Apr 29 | Jun 3–Jun 10 | 87 | fits: 55 days to maturity, 87 available after Jun 3. | Jun 21 |
| Basil | Apr 22 | Jun 17–Jun 17 | 73 | fits: 60 days to maturity, 73 available after Jun 17. | — |
| Cilantro | — | Apr 29–May 20 | 143 | two-plantings: Plant Apr 29 and again by Jul 17; both mature before Sep 19. | Jul 17 |
| Parsley | Mar 18 | Jun 3–Jun 10 | 108 | fits: 70 days to maturity, 108 available after Jun 3. | Jun 27 |
| Celery | Mar 18 | Jun 3–Jun 17 | 108 | head-start: Even planted out Jun 3, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Scallions | Mar 18 | Apr 29–May 13 | 157 | two-plantings: Plant Apr 29 and again by Jul 21; both mature before Oct 3. | Jul 21 |
| Turnip | — | Apr 29–May 13 | 157 | two-plantings: Plant Apr 29 and again by Jul 31; both mature before Oct 3. | Jul 31 |
| Kohlrabi | — | Apr 15–Apr 29 | 171 | two-plantings: Plant Apr 15 and again by Jul 26; both mature before Oct 3. | Jul 26 |
| Bok Choy | Apr 29 | May 20–May 27 | 122 | two-plantings: Plant May 20 and again by Jul 22; both mature before Sep 19. | Jul 22 |
| Collards | Mar 18 | Apr 29–May 13 | 157 | two-plantings: Plant Apr 29 and again by Jul 21; both mature before Oct 3. | Jul 21 |
| Cantaloupe | May 13 | Jun 10–Jun 17 | 66 | head-start: Even planted out Jun 10, the outdoor season is about 19 days short; choose an early variety or grow under cover. | — |
| Chives | Mar 4 | Jun 3–Jun 10 | 122 | fits: 90 days to maturity, 122 available after Jun 3. | — |
| Dill | — | Apr 1–Jun 24 | 171 | two-plantings: Plant Apr 1 and again by Jul 12; both mature before Sep 19. | Jul 12 |
| Oregano | Mar 18 | Jun 3–Jun 10 | 122 | fits: 80 days to maturity, 122 available after Jun 3. | — |
| Rosemary | Mar 4 | Jun 3–Jun 10 | 108 | fits: 80 days to maturity, 108 available after Jun 3. | — |
| Sage | Apr 1 | Jun 3–Jun 10 | 122 | fits: 75 days to maturity, 122 available after Jun 3. | — |
| Thyme | Mar 18 | Jun 3–Jun 10 | 122 | fits: 90 days to maturity, 122 available after Jun 3. | — |
| Calendula | Apr 15 | May 13–May 27 | 129 | two-plantings: Plant May 13 and again by Jul 17; both mature before Sep 19. | Jul 17 |
| Cosmos | Apr 29 | May 27–Jun 10 | 94 | fits: 60 days to maturity, 94 available after May 27. | Jun 16 |
| Lavender | Mar 4 | May 27–Jun 10 | 129 | fits: 90 days to maturity, 129 available after May 27. | — |
| Marigolds | Apr 15 | May 27–Jun 3 | 94 | fits: 50 days to maturity, 94 available after May 27. | Jun 26 |
| Melons | May 13 | Jun 10–Jun 17 | 66 | head-start: Even planted out Jun 10, the outdoor season is about 19 days short; choose an early variety or grow under cover. | — |
| Mint | — | May 27–Jun 10 | 129 | fits: 90 days to maturity, 129 available after May 27. | — |
| Nasturtiums | Apr 29 | May 27–Jun 3 | 94 | fits: 55 days to maturity, 94 available after May 27. | Jun 21 |
| Pole Beans | — | Jun 3–Jun 17 | 87 | fits: 65 days to maturity, 87 available after Jun 3. | Jun 11 |
| Spaghetti Squash | May 13 | Jun 10–Jun 17 | 73 | head-start: Even planted out Jun 10, the outdoor season is about 17 days short; choose an early variety or grow under cover. | — |
| Sunflowers | — | May 27–Jun 10 | 94 | fits: 70 days to maturity, 94 available after May 27. | Jun 6 |
| Tomatillos | Apr 1 | Jun 3–Jun 10 | 73 | head-start: Even planted out Jun 3, the outdoor season is about 2 days short; choose an early variety or grow under cover. | — |
| Watermelon | May 13 | Jun 3–Jun 10 | 73 | head-start: Even planted out Jun 3, the outdoor season is about 7 days short; choose an early variety or grow under cover. | — |
| Yellow Squash | May 13 | Jun 10–Jun 17 | 80 | fits: 55 days to maturity, 80 available after Jun 10. | Jun 21 |
| Zinnias | Apr 29 | May 27–Jun 10 | 94 | fits: 60 days to maturity, 94 available after May 27. | Jun 16 |
Month by month in Choteau
| 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 4), Lavender (Mar 4), Onion (Mar 4), Rosemary (Mar 4), Celery (Mar 18), Collards (Mar 18), +5 more. |
| April | Start indoors: Broccoli (Apr 1), Brussel Sprouts (Apr 1), Cabbage (Apr 1), Lettuce (Apr 1), Sage (Apr 1), Swiss Chard (Apr 1), +14 more. Direct sow from: Arugula (Apr 1), Beets (Apr 1), Dill (Apr 1), Peas (Apr 1), Radish (Apr 1), Spinach (Apr 1), +3 more. Transplant from: Broccoli (Apr 29), Brussel Sprouts (Apr 29), Cabbage (Apr 29), Collards (Apr 29), Kale (Apr 29), Lettuce (Apr 29), +2 more. Plant: Strawberry (Apr 22). |
| May | Start indoors: Cucumber (May 6), Butternut Squash (May 13), Cantaloupe (May 13), Melons (May 13), Pumpkin (May 13), Spaghetti Squash (May 13), +3 more. Direct sow from: Carrots (May 6), Potatoes (May 13), Sunflowers (May 27). Transplant from: Calendula (May 13), Swiss Chard (May 13), Bok Choy (May 20), Cauliflower (May 20), Cosmos (May 27), Lavender (May 27), +4 more. Last frost around May 27. |
| June | Direct sow from: Beans (Jun 3), Pole Beans (Jun 3). Transplant from: Celery (Jun 3), Chives (Jun 3), Corn (Jun 3), Okra (Jun 3), Oregano (Jun 3), Parsley (Jun 3), +17 more. Last sowing dates: Sunflowers (Jun 6), Brussel Sprouts (Jun 11), Pole Beans (Jun 11), Cosmos (Jun 16), Cucumber (Jun 16), Zinnias (Jun 16), +9 more. |
| July | Last sowing dates: Peas (Jul 2), Cabbage (Jul 11), Carrots (Jul 11), Beets (Jul 12), Dill (Jul 12), Swiss Chard (Jul 12), +9 more. |
| August | Last sowing dates: Arugula (Aug 10), Spinach (Aug 10), Radish (Aug 11). |
| September | Direct sow from: Garlic (Sep 12). First frost around September 12. |
| October | Last sowing dates: Garlic (Oct 3). |
| 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 Choteau, MT (ZIP 59422)?
The median last spring frost date for Choteau, MT (ZIP code 59422) is around May 27. 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 13; one in ten it runs past June 9.
What is the first fall frost date in Choteau, MT?
The median first fall frost date for Choteau, MT is around September 12. 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 2 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Choteau, MT?
The frost-free growing season in Choteau is about 108 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 Choteau (108 frost-free days, a short season), 29 of 56 planner crops fit outright, 15 get two plantings, 9 need an indoor start, 2 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Choteau, MT?
Choteau, MT is in USDA hardiness zone 4b (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 Choteau, MT?
Start tomatoes indoors Apr 22 and plant out Jun 10 in Choteau. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Choteau?
Two: plant Apr 29 and again by Jul 22; both mature before Sep 19.
When do I plant garlic in Choteau?
Sep 12 to Oct 3; it overwinters and is ready the following summer.
Can I grow Celery in Choteau?
Yes, with help. Even planted out Jun 3, the outdoor season is about 12 days short; choose an early variety or grow under cover.
Which nearby ZIP has a longer season?
Polson (ZIP 59860) has 144 frost-free days, 36 more than Choteau (ZIP 59422). See Polson ZIP 59860 frost dates
Nearby and related
- Frost dates for Great Falls, MT 59404 (54.5 mi)
- Frost dates for Great Falls, MT 59405 (68.5 mi)
- Frost dates for Polson, MT 59860 (79 mi)
- Frost dates for Columbia Falls, MT 59912 (88.4 mi)
- Frost dates for Helena, MT 59601 (90.7 mi)
- When to plant in MT
- When to plant Beans in MT
- When to plant Strawberries in MT
- When to plant Beets in MT
- When to plant Broccoli in MT
- When to plant Carrots in MT
- When to plant Kale in MT
- Look up another ZIP