Montana · zones 4a–5b
When to plant bell peppers in Montana.
Sow or transplant between May 31 to Jul 1 in a typical year, keyed to Montana's median last frost around May 15. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Bell Peppers dates for a typical Montana season.
1 · Start indoors
Apr 19 to May 20
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
May 31 to Jul 1
Keyed to the ~May 15 last frost. Sow 0.25" deep, 18" apart.
Harvest
~70 days later
~4 lb per plant over ~8 weeks.
Montana spans more than one climate: Zone 4 is the most common zone, but the state runs 4a to 5b. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
In Montana: watch for
The pests that find bell peppers here.
The short season here, about 131 frost-free days, keeps pepper, bell in front of aphids only briefly. One early row cover usually carries a planting through the worst of it.
Clusters on new growth, sticky leaves, curling tips. Green peach aphid spreads virus.
Organic fix: Blast with water, then insecticidal soap or neem.
Bacterial leaf spot
Small water-soaked spots that turn brown; badly spotted leaves drop.
Organic fix: Plant resistant varieties, avoid overhead watering, rotate out of nightshades.
Plant wilts and collapses at the soil line after a bed stays soggy.
Organic fix: Plant on raised ground for drainage; remove collapsed plants and do not replant there.
Tiny shot-hole pits peppering young leaves.
Organic fix: Row cover the seedlings; healthy transplants outgrow the damage.
Your season math: Montana gives bell peppers about 131 frost-free days, and it needs roughly 70 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting bell peppers in Montana: questions
When should I plant bell peppers in Montana?+
In a typical Montana year, sow bell peppers or set out transplants between May 31 to Jul 1, keyed to the state's median last frost around May 15. Your exact dates shift with your ZIP code and microclimate.
When do I start bell peppers seeds indoors in Montana?+
Start seeds inside about 6 weeks before set-out: roughly Apr 19 to May 20 for a typical Montana season.
What USDA zone is Montana?+
Montana spans zones 4a–5b, mostly zone 4. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many bell peppers plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.