When to plant pole beans in Montana
Montana’s average last spring frost is May 15, and the first fall frost typically arrives around September 15 — about 123 frost-free days (USDA zones 3a, 3b, 4a, 4b, 5a, 5b, 6a). Pole Bean needs 60–70 days to mature, which fits comfortably within Montana's growing season.
Montana covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant pole beans in Montana: the short answer
For a spring planting, sow May 17 – Jun 5. Wait until the soil is at least 60°F and frost is over.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow pole beans in Montana, step by step
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 6.0 and 7.5. Dig in compost before planting.
- Sow outdoors (May 17 – Jun 5). Space plants about 6 inches apart in rows 42 inches apart, sowing seed 1.5 inches deep. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: Mexican bean beetle, aphids, bean leaf beetle. Diseases and disorders: anthracnose, bacterial blight, bean rust, bean mosaic virus.
- Harvest (from about Jul 21 – Jul 31). Pole Bean takes 60-70 days to reach harvest. One well-tended sowing keeps producing for 6-8 weeks if you pick often. Set the trellis at sowing time.
Figures come from our crop data; dates use Montana’s average frost dates. More in the full pole bean growing guide.
Pole Bean planting dates by USDA zone in Montana
Montana spans USDA zones 3a, 3b, 4a, 4b, 5a, 5b, 6a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the pole bean dates shift with them.
When to plant pole beans in nearby states
Questions gardeners in Montana ask
When is the best time to plant pole beans in Montana?
Sow pole beans in Montana between May 17 and June 5. That timing is set by Montana's average last spring frost of May 15; Montana spans several climates, so cooler and higher parts of the state run later.
What is the latest I can plant pole beans in Montana?
About July 17. Pole beans need at least 60 days to mature, and frost around September 15 ends the season, so later plantings risk being cut short.
When will pole beans planted in Montana be ready to harvest?
Planted on time, pole beans are usually ready from about July 21 to July 31, 60-70 days after sowing.
When is the last frost in Montana?
On average around May 15, with the first fall frost around September 15 - about 123 frost-free days. Your town may differ by two weeks or more.