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When to Plant Pole Beans in Boise County, ID

Pole beans are climbing varieties of green beans that produce over a much longer season than bush types. They require trellising but yield more per square foot.

Boise County, Idaho is in USDA Zone 5b. The average last spring frost is May 18 and the first fall frost is September 27, giving you a growing season of approximately 132 days.

At an elevation of 8,023 feet, Boise County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Pole Beans during the growing season.

Boise County, ID (Zone 5b) Short season
132 days
Last Spring Frost May 18
132 growing days
First Fall Frost September 27

Boise County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Start indoors: Mar 10 Transplant: May 19 🍅 Harvest: Jul 14 – Sep 8
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Mar 23 Transplant: Jun 1 🍅 Harvest: Jul 27 – Sep 21
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Apr 21 Transplant: Jun 30 🍅 Harvest: Aug 25 – Oct 20

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Boise County

How your county's soil matches Pole Beans's growing requirements.

Soil pH

Your soil pH (6.7โ€“7.7) is more alkaline than Pole Beans prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Boise County is excellent for Pole Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Pole Beans.

How to Plant Pole Beans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Pole Beans

2
successive plantings in your 132-day season

Sow every 6.3 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 320 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Pole Beans

Pole Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Pole Beans Needs Rainfall You Supplement Action
Jan โ€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Jun 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Aug 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Sep 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Oct โ€” 2.4" 0" โ„๏ธ Dormant
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Boise County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Pole Beans Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Pole Beans needs ~906 GDD — county provides 1,914 GDD Excellent fit

Pole Beans Planting Timeline โ€” Boise County, ID

Pole Beans Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors June 1 Jun 1 โ€“ Jun 15
Direct Sow May 25 May 25 โ€“ Jun 15
Harvest July 27 Jul 27 โ€“ Sep 21

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors
May Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

55โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

132 days in Boise County

Growing Tips for Pole Beans in Boise County

Direct sow Pole Beans outdoors after May 18 in Boise County when soil has warmed and frost danger has passed.

Common pests for Pole Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

Boise County receives only 24" of rain annually. Pole Beans needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Provide sturdy 6-8 foot poles, tepees, or trellises. Direct sow after last frost. Pick regularly to encourage continued production. Beans fix nitrogen benefiting following crops.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pole Beans in Boise County, ID?

Boise County is in Zone 5b with an average last frost of May 18. Plan your Pole Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Boise County, ID?

Boise County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 18 and first fall frost is September 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Boise County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Boise County, ID. Local conditions may vary. Last updated: April 2026.