When to plant pole beans in Idaho
Idaho’s average last spring frost is May 10, and the first fall frost typically arrives around September 25 — about 138 frost-free days (USDA zones 3b, 4b, 5b, 6a, 6b, 7a). Pole Bean needs 60–70 days to mature, which fits comfortably within Idaho's growing season.
Idaho 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 Idaho: the short answer
For a spring planting, sow May 12 – May 31. 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 Idaho, 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 12 – May 31). 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 16 – Jul 26). 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 Idaho’s average frost dates. More in the full pole bean growing guide.
Pole Bean planting dates by USDA zone in Idaho
Idaho spans USDA zones 3b, 4b, 5b, 6a, 6b, 7a. 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 Idaho ask
When is the best time to plant pole beans in Idaho?
Sow pole beans in Idaho between May 12 and May 31. That timing is set by Idaho's average last spring frost of May 10; Idaho spans several climates, so cooler and higher parts of the state run later.
What is the latest I can plant pole beans in Idaho?
About July 27. Pole beans need at least 60 days to mature, and frost around September 25 ends the season, so later plantings risk being cut short.
When will pole beans planted in Idaho be ready to harvest?
Planted on time, pole beans are usually ready from about July 16 to July 26, 60-70 days after sowing.
When is the last frost in Idaho?
On average around May 10, with the first fall frost around September 25 - about 138 frost-free days. Your town may differ by two weeks or more.