Bozeman, Montana planting calendar and frost dates
Bozeman is in USDA hardiness zone 5a. The last spring frost typically comes around May 23 and the first fall frost around September 23, giving about 123 frost-free days a year.
- Hardiness zone
- Zone 5a
- Typical last frost
- May 23
- Typical first frost
- September 23
- Frost-free season
- 123 days
Frost dates in Bozeman
Last spring frost
- May 5Risky: frost later than this in 9 years out of 10
- May 23Typical: a later frost in half of years
- June 12Safe: a later frost only 1 year in 10
First fall frost
- September 4Risky: frost earlier than this 1 year in 10
- September 23Typical: an earlier frost in half of years
- October 6Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 123 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around May 2 and returns around October 3.
NOAA U.S. Climate Normals 1991-2020 for Bozeman 6 W Exp Farm, 2.4 miles NNE of the city center. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers.
What to plant each month in Bozeman
January
Start indoors: onions
February
Start indoors: collard greens, leeks, onions, petunias, ranunculus
March
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, collard greens, ginger, kale, leeks, lettuce, marigolds, onions, oregano, parsley, petunias, ranunculus, rosemary, sage, snapdragons
April
Start indoors: black-eyed susans, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, lettuce, marigolds, nasturtiums, peppers, ranunculus, sage, snapdragons, spinach, swiss chard, tomatoes, zinnias
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, onions, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
May
Start indoors: basil, cantaloupes, cosmos, cucumbers, eggplants, okra, peppers, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zinnias, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garden mums, ginger, gladioli, grapes, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, perennial ryegrass, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, turnips, zinnias
June
Start indoors: cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, basil, cantaloupes, cucumbers, eggplants, garden mums, ginger, grapes, green beans, green onions, kentucky bluegrass, lavenders, lilies, marigolds, mints, nasturtiums, oregano, parsley, peppers, perennial ryegrass, petunias, pumpkins, rosemary, sage, st. augustinegrass, sunflowers, sweet corn, sweet peas, tall fescue, thyme, tomatoes, watermelons, winter squash, zinnias, zucchini
Plant for fall: brussels sprouts, collard greens, lettuce, swiss chard
July
Plant or sow outdoors: bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, green beans, green onions, okra, peanuts, peppers, pumpkins, st. augustinegrass, sweet potatoes, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, daylilies, hostas, hydrangeas, kale, lettuce, peas, radishes, roses, saffron, snapdragons, spinach, swiss chard, turnips
August
Plant or sow outdoors: bermudagrass, centipedegrass, st. augustinegrass, zoysiagrass
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, lilies, ornamental alliums, peonies, radishes, roses, saffron, spinach, tulips, turnips
September
Plant for fall: crocuses, daffodils, daylilies, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
October
Plant for fall: crocuses, garlic, hyacinths, ornamental alliums, tulips
Frost dates and zones by ZIP code in Bozeman
Bozeman's 2 main ZIP codes take their frost dates from 2 different NOAA stations: the typical last frost ranges from May 23 in 59718 to May 26 in 59715. Every one of them is in zone 5a.
Planting dates for popular crops in Bozeman
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Apr 27 to May 11 | Jun 22 to Jul 6 | — |
| Strawberries | — | Apr 11 to 25 | — |
| Lettuce | Mar 28 to Apr 11 | May 16 to 30 | Jun 24 to Jul 29 |
| Cilantro | Apr 11 to 25 | May 23 to 30 | — |
| Basil | May 4 to 18 | Jun 22 to 29 | — |
| Potatoes | — | May 10 to 17 | — |
| Garlic | — | Apr 11 to 25 | Sep 23 to Oct 7 |
| Onions | Jan 31 to Mar 14 | Apr 25 to May 9 | — |
| Cucumbers | May 25 to Jun 8 | Jun 22 to Jul 6 | — |
| Pumpkins | May 25 to Jun 8 | Jun 22 to Jul 6 | — |
| Peppers | Apr 6 to May 4 | Jun 22 to Jul 6 | — |
| Carrots | — | May 2 to 23 | Jul 1 to 22 |
| Sweet Potatoes | — | Jul 8 to 15 | — |
| Watermelons | May 18 to Jun 1 | Jun 22 to Jul 6 | — |
| Sweet Corn | — | May 23 to Jun 6 | — |
| Green Beans | — | Jun 22 to Jul 6 | — |
| Zucchini | May 25 to Jun 8 | Jun 22 to Jul 6 | — |
| Broccoli | Mar 7 to 28 | Apr 25 to May 9 | Jul 8 to Aug 5 |
| Peas | — | Apr 11 to 25 | Jul 1 to 15 |
| Spinach | Apr 11 to 18 | May 16 to 30 | Jul 15 to Aug 19 |
| Sunflowers | — | May 23 to Jun 13 | — |
| Zinnias | Apr 25 to May 2 | May 23 to Jun 6 | — |
| Tulips | — | — | Aug 12 to Oct 7 |
| Daffodils | — | — | Aug 12 to Sep 23 |
| Grass Seed | — | Apr 11 to 25 | Aug 12 to 26 |
Nearby cities
- Billings, MT zone 5a, last frost May 10
- Great Falls, MT zone 4b, last frost May 19
- Idaho Falls, ID zone 5b, last frost May 23
- Missoula, MT zone 5b, last frost May 10
- Pocatello, ID zone 6a, last frost May 16
- Twin Falls, ID zone 6b, last frost May 9
Planting in MontanaAbout zone 5aPrintable calendar for Bozeman
Questions
When is the last frost in Bozeman?
Around May 23 in a typical year, based on NOAA's 1991-2020 records for Bozeman 6 W Exp Farm. There is still a 1 in 10 chance of frost after June 12.
What planting zone is Bozeman in?
USDA hardiness zone 5a (2023 map). The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Bozeman?
Start seeds indoors April 27 to May 11 and set plants out June 22 to July 6.
When is the first frost in Bozeman?
Around September 23 in a typical year, and before September 4 about 1 year in 10.