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When to plant Pole Beans in Boulder County County,

Plant Pole Beans in Boulder County County, between May 21 and June 11 — the only viable window. Zone 6a's short season (135 frost-free days) rules out a fall crop.

When to Plant Pole Beans in Boulder County, CO

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.

Boulder County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 7,657 feet, Boulder County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Pole Beans during the growing season.

Boulder County, CO (Zone 6a) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Boulder County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

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 1.7" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Boulder County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Pole Beans Planting Timeline — Boulder County, CO

Pole Beans Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors May 28 May 28 – Jun 11
Direct Sow May 21 May 21 – Jun 11
Harvest July 23 Jul 23 – Sep 17

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Boulder County

Growing Tips for Boulder County

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 Boulder County, CO?

Boulder County is in Zone 6a with an average last frost of May 14. Plan your Pole Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boulder County, CO?

Boulder County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.

When should I plant Pole Beans in Boulder County County, ?

In Boulder County County, , plant Pole Beans after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.

What growing zone is Boulder County County, for Pole Beans?

Boulder County County sits in USDA Zone 6a. Pole Beans grows reliably in zones 3a through 11b, so it's a good fit here.

Can Pole Beans grow in Boulder County County's climate?

Yes — Pole Beans grows well in Boulder County County's temperate climate. Boulder County County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.

🌱

Your Boulder County Garden Planner — Free

A 22-page printable planner built for Boulder County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Boulder County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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