Frost Dates for Kalispell, MT 59901
Last spring frost May 24 · First fall frost September 16 · 115 frost-free days · USDA Zone 5b
ZIP 59901 has about 63,200 people.
Short season: 115 frost-free days. Spring frost risk spans May 6–June 10 (35 days). Fall frost risk spans September 3–September 28 (25 days).
Frost probability for 59901
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 10 | May 24 | May 6 |
| Fall (first frost) | September 3 | September 16 | September 28 |
Dates come from NOAA 1971–2000 freeze probabilities at CRESTON (20.6 km away); the 50% date is the median year.
Which crops fit a 115-day season in Kalispell
In Kalispell (115 frost-free days, a short season), 32 of 56 planner crops fit outright, 15 get two plantings, 8 need an indoor start, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 19 | Jun 7–Jun 14 | 73 | head-start: Even planted out Jun 7, the outdoor season is about 7 days short; choose an early variety or grow under cover. | — |
| Pepper | Apr 12 | Jun 7–Jun 14 | 73 | head-start: Even planted out Jun 7, the outdoor season is about 2 days short; choose an early variety or grow under cover. | — |
| Lettuce | Mar 29 | Apr 26–May 3 | 150 | two-plantings: Plant Apr 26 and again by Jul 26; both mature before Sep 23. | Jul 26 |
| Carrots | — | May 3–May 10 | 157 | fits: 70 days to maturity, 157 available after May 3. | Jul 15 |
| Cucumber | May 3 | Jun 7–Jun 14 | 87 | fits: 60 days to maturity, 87 available after Jun 7. | Jun 20 |
| Beans | — | May 31–Jun 14 | 101 | fits: 60 days to maturity, 101 available after May 31. | Jun 27 |
| Peas | — | Mar 29–Jun 7 | 178 | fits: 65 days to maturity, 178 available after Mar 29. | Jul 6 |
| Zucchini | May 10 | Jun 7–Jun 14 | 87 | fits: 55 days to maturity, 87 available after Jun 7. | Jun 25 |
| Onion | Mar 1 | Apr 26–May 10 | 150 | fits: 100 days to maturity, 150 available after Apr 26. | — |
| Spinach | — | Mar 29–May 17 | 192 | two-plantings: Plant Mar 29 and again by Aug 14; both mature before Oct 7. | Aug 14 |
| Kale | Mar 15 | Apr 26–May 10 | 164 | two-plantings: Plant Apr 26 and again by Jul 30; both mature before Oct 7. | Jul 30 |
| Broccoli | Mar 29 | Apr 26–May 10 | 150 | fits: 80 days to maturity, 150 available after Apr 26. | Jun 21 |
| Cabbage | Mar 29 | Apr 26–May 10 | 164 | fits: 70 days to maturity, 164 available after Apr 26. | Jul 15 |
| Radish | — | Mar 29–Jun 21 | 178 | two-plantings: Plant Mar 29 and again by Aug 15; both mature before Sep 23. | Aug 15 |
| Beets | — | Mar 29–Jun 21 | 178 | two-plantings: Plant Mar 29 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Potatoes | — | May 10–May 17 | 136 | fits: 90 days to maturity, 136 available after May 10. | — |
| Garlic | — | Sep 16 | 220 | overwinter: Plant Sep 16 to Oct 7; harvest the following summer. | Oct 7 |
| Strawberry | — | Apr 19–Jun 14 | 171 | perennial: A perennial: plant Apr 19; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 26 | May 31–Jun 7 | 87 | fits: 75 days to maturity, 87 available after May 31. | — |
| Pumpkin | May 10 | Jun 7–Jun 7 | 80 | head-start: Even planted out Jun 7, the outdoor season is about 20 days short; choose an early variety or grow under cover. | — |
| Cauliflower | Apr 12 | May 17–May 31 | 129 | fits: 75 days to maturity, 129 available after May 17. | Jun 26 |
| Swiss Chard | Mar 29 | May 10–May 10 | 136 | two-plantings: Plant May 10 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Arugula | — | Mar 29–Jun 21 | 192 | two-plantings: Plant Mar 29 and again by Aug 14; both mature before Oct 7. | Aug 14 |
| Brussel Sprouts | Mar 29 | Apr 26–May 10 | 164 | fits: 100 days to maturity, 164 available after Apr 26. | Jun 15 |
| Butternut Squash | May 10 | Jun 7–Jun 14 | 80 | head-start: Even planted out Jun 7, the outdoor season is about 20 days short; choose an early variety or grow under cover. | — |
| Eggplant | Apr 5 | Jun 7–Jun 14 | 73 | fits: 70 days to maturity, 73 available after Jun 7. | — |
| Okra | Apr 26 | May 31–Jun 7 | 94 | fits: 55 days to maturity, 94 available after May 31. | Jun 25 |
| Basil | Apr 19 | Jun 14–Jun 14 | 80 | fits: 60 days to maturity, 80 available after Jun 14. | Jun 20 |
| Cilantro | — | Apr 26–May 17 | 150 | two-plantings: Plant Apr 26 and again by Jul 21; both mature before Sep 23. | Jul 21 |
| Parsley | Mar 15 | May 31–Jun 7 | 115 | fits: 70 days to maturity, 115 available after May 31. | Jul 1 |
| Celery | Mar 15 | May 31–Jun 14 | 115 | head-start: Even planted out May 31, the outdoor season is about 5 days short; choose an early variety or grow under cover. | — |
| Scallions | Mar 15 | Apr 26–May 10 | 164 | two-plantings: Plant Apr 26 and again by Jul 25; both mature before Oct 7. | Jul 25 |
| Turnip | — | Apr 26–May 10 | 164 | two-plantings: Plant Apr 26 and again by Aug 4; both mature before Oct 7. | Aug 4 |
| Kohlrabi | — | Apr 12–Apr 26 | 178 | two-plantings: Plant Apr 12 and again by Jul 30; both mature before Oct 7. | Jul 30 |
| Bok Choy | Apr 26 | May 17–May 24 | 129 | two-plantings: Plant May 17 and again by Jul 26; both mature before Sep 23. | Jul 26 |
| Collards | Mar 15 | Apr 26–May 10 | 164 | two-plantings: Plant Apr 26 and again by Jul 25; both mature before Oct 7. | Jul 25 |
| Cantaloupe | May 10 | Jun 7–Jun 14 | 73 | head-start: Even planted out Jun 7, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Chives | Mar 1 | May 31–Jun 7 | 129 | fits: 90 days to maturity, 129 available after May 31. | — |
| Dill | — | Mar 29–Jun 21 | 178 | two-plantings: Plant Mar 29 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Oregano | Mar 15 | May 31–Jun 7 | 129 | fits: 80 days to maturity, 129 available after May 31. | — |
| Rosemary | Mar 1 | May 31–Jun 7 | 115 | fits: 80 days to maturity, 115 available after May 31. | — |
| Sage | Mar 29 | May 31–Jun 7 | 129 | fits: 75 days to maturity, 129 available after May 31. | — |
| Thyme | Mar 15 | May 31–Jun 7 | 129 | fits: 90 days to maturity, 129 available after May 31. | — |
| Calendula | Apr 12 | May 10–May 24 | 136 | two-plantings: Plant May 10 and again by Jul 21; both mature before Sep 23. | Jul 21 |
| Cosmos | Apr 26 | May 24–Jun 7 | 101 | fits: 60 days to maturity, 101 available after May 24. | Jun 20 |
| Lavender | Mar 1 | May 24–Jun 7 | 136 | fits: 90 days to maturity, 136 available after May 24. | — |
| Marigolds | Apr 12 | May 24–May 31 | 101 | fits: 50 days to maturity, 101 available after May 24. | Jun 30 |
| Melons | May 10 | Jun 7–Jun 14 | 73 | head-start: Even planted out Jun 7, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Mint | — | May 24–Jun 7 | 136 | fits: 90 days to maturity, 136 available after May 24. | — |
| Nasturtiums | Apr 26 | May 24–May 31 | 101 | fits: 55 days to maturity, 101 available after May 24. | Jun 25 |
| Pole Beans | — | May 31–Jun 14 | 94 | fits: 65 days to maturity, 94 available after May 31. | Jun 15 |
| Spaghetti Squash | May 10 | Jun 7–Jun 14 | 80 | head-start: Even planted out Jun 7, the outdoor season is about 10 days short; choose an early variety or grow under cover. | — |
| Sunflowers | — | May 24–Jun 7 | 101 | fits: 70 days to maturity, 101 available after May 24. | Jun 10 |
| Tomatillos | Mar 29 | May 31–Jun 7 | 80 | fits: 75 days to maturity, 80 available after May 31. | — |
| Watermelon | May 10 | May 31–Jun 7 | 80 | fits: 80 days to maturity, 80 available after May 31. | — |
| Yellow Squash | May 10 | Jun 7–Jun 14 | 87 | fits: 55 days to maturity, 87 available after Jun 7. | Jun 25 |
| Zinnias | Apr 26 | May 24–Jun 7 | 101 | fits: 60 days to maturity, 101 available after May 24. | Jun 20 |
Month by month in Kalispell
| 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 1), Lavender (Mar 1), Onion (Mar 1), Rosemary (Mar 1), Celery (Mar 15), Collards (Mar 15), +12 more. Direct sow from: Arugula (Mar 29), Beets (Mar 29), Dill (Mar 29), Peas (Mar 29), Radish (Mar 29), Spinach (Mar 29). |
| April | Start indoors: Eggplant (Apr 5), Calendula (Apr 12), Cauliflower (Apr 12), Marigolds (Apr 12), Pepper (Apr 12), Basil (Apr 19), +7 more. Direct sow from: Kohlrabi (Apr 12), Cilantro (Apr 26), Turnip (Apr 26). Transplant from: Broccoli (Apr 26), Brussel Sprouts (Apr 26), Cabbage (Apr 26), Collards (Apr 26), Kale (Apr 26), Lettuce (Apr 26), +2 more. Plant: Strawberry (Apr 19). |
| May | Start indoors: Cucumber (May 3), Butternut Squash (May 10), Cantaloupe (May 10), Melons (May 10), Pumpkin (May 10), Spaghetti Squash (May 10), +3 more. Direct sow from: Carrots (May 3), Potatoes (May 10), Sunflowers (May 24), Beans (May 31), Pole Beans (May 31). Transplant from: Calendula (May 10), Swiss Chard (May 10), Bok Choy (May 17), Cauliflower (May 17), Cosmos (May 24), Lavender (May 24), +15 more. Last frost around May 24. |
| June | Transplant from: Butternut Squash (Jun 7), Cantaloupe (Jun 7), Cucumber (Jun 7), Eggplant (Jun 7), Melons (Jun 7), Pepper (Jun 7), +6 more. Last sowing dates: Sunflowers (Jun 10), Brussel Sprouts (Jun 15), Pole Beans (Jun 15), Basil (Jun 20), Cosmos (Jun 20), Cucumber (Jun 20), +9 more. |
| July | Last sowing dates: Parsley (Jul 1), Peas (Jul 6), Cabbage (Jul 15), Carrots (Jul 15), Beets (Jul 16), Dill (Jul 16), +9 more. |
| August | Last sowing dates: Turnip (Aug 4), Arugula (Aug 14), Spinach (Aug 14), Radish (Aug 15). |
| September | Direct sow from: Garlic (Sep 16). First frost around September 16. |
| October | Last sowing dates: Garlic (Oct 7). |
| 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 Kalispell, MT (ZIP 59901)?
The median last spring frost date for Kalispell, MT (ZIP code 59901) is around May 24. 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 6; one in ten it runs past June 10.
What is the first fall frost date in Kalispell, MT?
The median first fall frost date for Kalispell, MT is around September 16. 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 3 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Kalispell, MT?
The frost-free growing season in Kalispell is about 115 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 Kalispell (115 frost-free days, a short season), 32 of 56 planner crops fit outright, 15 get two plantings, 8 need an indoor start, 1 crop is perennial.
What USDA hardiness zone is Kalispell, MT?
Kalispell, MT is in USDA hardiness zone 5b (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 Kalispell, MT?
Start tomatoes indoors Apr 19 and plant out Jun 7 in Kalispell. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Kalispell?
Two: plant Apr 26 and again by Jul 26; both mature before Sep 23.
When do I plant garlic in Kalispell?
Sep 16 to Oct 7; it overwinters and is ready the following summer.
Can I grow Celery in Kalispell?
Yes, with help. Even planted out May 31, the outdoor season is about 5 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, 29 more than Kalispell (ZIP 59901). See Polson ZIP 59860 frost dates
Nearby and related
- Frost dates for Whitefish, MT 59937 (15.1 mi)
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