Blog

When to Plant Green Beans in Adams County, CO

Adams County, Colorado Zone 6a May

Your May gardening checklist

Here's what deserves your attention in Adams County, Colorado this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost May 4
Avg. first frost October 5
Soil temp (4") 40°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Sow green beans where they'll grow

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

Instant PDF download. No spam, unsubscribe any time.

Green beans are a warm-season staple available as bush or pole types. Bush beans produce a concentrated harvest while pole beans provide a longer picking season.

Adams County, Colorado is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.

At an elevation of 5,827 feet, Adams County receives approximately 23.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Green Beans during the growing season.

Adams County, CO (Zone 6a) Moderate season
154 days
Last Spring Frost May 4
154 growing days
First Fall Frost October 5
Share this guide:

Adams County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 19
Recommended (50%) ✓ Fits season (42 days to spare)
Transplant: May 4 🍅 Harvest: Jun 29 – Aug 24
Safe Start (90%) ✓ Fits season (37 days to spare)
Transplant: May 21 🍅 Harvest: Jul 16 – Sep 10

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 Adams County

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Green Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Adams County is excellent for Green Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Green Beans.

How to Plant Green Beans

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

Succession Planting Green Beans

3
successive plantings in your 154-day season

Sow every 5.7 weeks. Last sowing by Aug 01 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 408 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Green Beans

Green Beans needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Green Beans Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 3.9" 2.5" 1.4" 💧 Light watering
Jun 3.9" 1.6" 2.3" 🚿 Regular watering
Jul 3.9" 2.1" 1.8" 💧 Light watering
Aug 3.9" 2.8" 1.1" 💧 Light watering
Sep 3.9" 1.8" 2.1" 🚿 Regular watering
Oct 3.9" 2.3" 1.6" 💧 Light watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Green 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" — every day above 50°F 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.

Green Beans needs ~877 GDD — county provides 2,348 GDD Excellent fit

Green Beans Planting Timeline — Adams County, CO

Green Beans Planting Calendar

Activity When Date Range
Direct Sow May 11 May 11 – Jun 1
Harvest July 6 Jul 6 – Aug 31

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

154 days in Adams County

Growing Tips for Green Beans in Adams County

Direct sow Green Beans outdoors after May 04 in Adams County when soil has warmed and frost danger has passed.

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

Adams County receives only 24" of rain annually. Green Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost when soil is warm. Provide sturdy supports for pole varieties. Pick beans regularly when young and tender to encourage continued production.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Green Beans Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Allow pods to dry fully on vine until they rattle.
Storage Store airtight; viable 4 years at 35°F, under 45% humidity.

Avoid harvesting during damp weather. Isolate 25 ft between varieties.

Frequently Asked Questions

When should I plant Green Beans in Adams County, CO?

Adams County is in Zone 6a with an average last frost of May 4. Plan your Green Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, CO?

Adams County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 4 and first fall frost is October 5.

🌱

Your Adams County Garden Planner — Free

A 24-page printable planner built for Adams 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.