Billings, Montana planting calendar and frost dates
Billings is in USDA hardiness zone 5a. The last spring frost typically comes around May 10 and the first fall frost around October 1, giving about 142 frost-free days a year.
- Hardiness zone
- Zone 5a
- Typical last frost
- May 10
- Typical first frost
- October 1
- Frost-free season
- 142 days
Frost dates in Billings
Last spring frost
- April 26Risky: frost later than this in 9 years out of 10
- May 10Typical: a later frost in half of years
- May 24Safe: a later frost only 1 year in 10
First fall frost
- September 19Risky: frost earlier than this 1 year in 10
- October 1Typical: an earlier frost in half of years
- October 15Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 142 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 April 27 and returns around October 12.
NOAA U.S. Climate Normals 1991-2020 for Billings Wtp, 1.2 miles SE 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 Billings
January
Start indoors: onions
February
Start indoors: broccoli, cauliflower, collard greens, kale, leeks, onions, petunias, ranunculus
March
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, kale, leeks, lettuce, marigolds, nasturtiums, onions, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons, spinach, swiss chard
Plant or sow outdoors: black-eyed susans, blueberries, garlic, grapes, grass seed, hollyhocks, onions, peas, poppies, raspberries, rhubarb, strawberries, turnips, wildflowers
April
Start indoors: basil, cantaloupes, celery, cilantro, eggplants, marigolds, nasturtiums, peppers, ranunculus, spinach, swiss chard, tomatoes, watermelons
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, snapdragons, spinach, strawberries, swiss chard, turnips, wildflowers
May
Start indoors: cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, carrots, cauliflower, chives, cilantro, dahlias, dill, figs, garden mums, ginger, gladioli, grapes, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, perennial ryegrass, petunias, potatoes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme
June
Start indoors: zinnias
Plant or sow outdoors: asparagus, basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, garden mums, green beans, green onions, okra, peanuts, peppers, pumpkins, st. augustinegrass, sweet potatoes, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
Plant for fall: brussels sprouts
July
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, green onions, okra, peanuts, st. augustinegrass, zinnias, zoysiagrass
Plant for fall: bearded irises, beets, broccoli, brussels sprouts, cabbages, carrots, cauliflower, collard greens, daylilies, kale, lettuce, peas, radishes, snapdragons, spinach, swiss chard, turnips
August
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hydrangeas, kale, lettuce, lilies, ornamental alliums, peonies, radishes, roses, saffron, snapdragons, spinach, tulips, turnips
September
Plant for fall: crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, kale, lilies, ornamental alliums, peonies, radishes, saffron, tulips
October
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
Frost dates and zones by ZIP code in Billings
All 4 of Billings's main ZIP codes take their frost dates from Billings Wtp, so the dates on this page apply across the city. Every one of them is in zone 5a.
Planting dates for popular crops in Billings
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Apr 7 to 21 | Jun 2 to 16 | — |
| Strawberries | — | Mar 29 to Apr 12 | — |
| Lettuce | Mar 15 to 29 | May 3 to 17 | Jul 2 to Aug 6 |
| Cilantro | Mar 29 to Apr 12 | May 10 to 17 | — |
| Basil | Apr 14 to 28 | Jun 2 to 9 | — |
| Potatoes | — | May 2 to 9 | — |
| Garlic | — | Mar 29 to Apr 12 | Oct 1 to 15 |
| Onions | Jan 18 to Mar 1 | Apr 12 to 26 | — |
| Cucumbers | May 5 to 19 | Jun 2 to 16 | — |
| Pumpkins | May 5 to 19 | Jun 2 to 16 | — |
| Peppers | Mar 17 to Apr 14 | Jun 2 to 16 | — |
| Carrots | — | Apr 19 to May 10 | Jul 9 to 30 |
| Sweet Potatoes | — | Jun 21 to 28 | — |
| Watermelons | Apr 28 to May 12 | Jun 2 to 16 | — |
| Sweet Corn | — | May 10 to 24 | — |
| Green Beans | — | Jun 2 to 16 | — |
| Zucchini | May 5 to 19 | Jun 2 to 16 | — |
| Broccoli | Feb 22 to Mar 15 | Apr 12 to 26 | Jul 16 to Aug 13 |
| Peas | — | Mar 29 to Apr 12 | Jul 9 to 23 |
| Spinach | Mar 29 to Apr 5 | May 3 to 17 | Jul 23 to Aug 27 |
| Sunflowers | — | May 10 to 31 | — |
| Zinnias | Jun 11 to 18 | Jul 9 to 23 | — |
| Tulips | — | — | Aug 20 to Oct 15 |
| Daffodils | — | — | Aug 20 to Oct 1 |
| Grass Seed | — | Mar 29 to Apr 12 | Aug 20 to Sep 3 |
Nearby cities
- Bozeman, MT zone 5a, last frost May 23
- Great Falls, MT zone 4b, last frost May 19
- Casper, WY zone 5a, last frost May 26
- 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
Planting in MontanaAbout zone 5aPrintable calendar for Billings
Questions
When is the last frost in Billings?
Around May 10 in a typical year, based on NOAA's 1991-2020 records for Billings Wtp. There is still a 1 in 10 chance of frost after May 24.
What planting zone is Billings 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 Billings?
Start seeds indoors April 7 to 21 and set plants out June 2 to 16.
When is the first frost in Billings?
Around October 1 in a typical year, and before September 19 about 1 year in 10.