When to plant sunflowers in Montana

Sunflowers
Sow outdoors in Billings
May 4–May 25

Across Montana the window opens between May 4 and June 13. Find your city below; the dates follow each town's own average last frost.

Sow outdoors, Billings
May 4–May 25
Last sowing for a harvest
Jun 15
Last frost, Billings
May 4

Sow outdoors up to 3 weeks after the last frost. Sow every two weeks until midsummer for flowers through fall.

Sunflowers planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
JanFebMarAprMayJunJulAugSepOctNovDec
BillingsMay 4–May 25
MissoulaMay 10–May 31
Great FallsMay 6–May 27
BozemanMay 26–Jun 16
Butte-Silver BowJun 13–Jul 4
HelenaMay 9–May 30
KalispellMay 31–Jun 21

In Butte-Silver Bow, Kalispell the frost-free season is shorter than sunflowers need. Start plants indoors and pick early varieties.

Questions

When should I plant sunflowers in Montana?

In Billings, sow outdoors from May 4 to May 25. Across Montana the window opens between May 4 and June 13, depending on the local last frost.

How is this date worked out?

Sow outdoors up to 3 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

Is the season long enough for sunflowers everywhere in Montana?

Not quite. In Butte-Silver Bow, Kalispell the frost-free season is shorter than the time sunflowers need to ripen. Start plants indoors and pick an early variety.

More for Montana

Sunflowers in other states

Frost dates for every city in Montana