Blog

When to plant Lima Beans in Jefferson County, CO

Plant Lima Beans in Jefferson County during the brief May 21–June 11 window. With 135 frost-free days, fall plantings can't mature before September 26.

When to Plant Lima Beans in Jefferson County, CO

Jefferson County, Colorado Zone 6a June

June in Jefferson County, Colorado — your action list

A quick June briefing for Jefferson County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 14
Avg. first frost September 26
Soil temp (4") 56°F
Watering High
Pest pressure High
Daylight 14.8 hrs

Instant PDF download. No spam, unsubscribe any time.

Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.

Jefferson 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 5,376 feet, Jefferson County receives approximately 22.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Lima Beans to ensure they mature before fall.

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

Jefferson County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Lima Beans Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Aug 16
Recommended (50%) ✓ Fits season (30 days to spare)
Transplant: May 14 🍅 Harvest: Jul 16 – Aug 27
Safe Start (90%) ✓ Fits season (23 days to spare)
Transplant: Jun 10 🍅 Harvest: Aug 12 – Sep 23

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 Jefferson County

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

Soil pH

Your soil pH (6.8–7.7) is more alkaline than Lima Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Lima Beans.

How to Plant Lima Beans

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

Succession Planting Lima Beans

2
successive plantings in your 135-day season

Sow every 6.9 weeks. Last sowing by Jun 28 to harvest before frost.

Lima Beans Water Budget

Plant needs
0.9″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 279 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lima Beans

Lima 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 Lima Beans Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 3.9" 2.6" 1.3" 💧 Light watering
Jun 3.9" 1.8" 2.1" 🚿 Regular watering
Jul 3.9" 1.9" 2" 🚿 Regular watering
Aug 3.9" 2.4" 1.5" 💧 Light watering
Sep 3.9" 1.7" 2.2" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

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

Lima 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.

Lima Beans needs ~975 GDD — county provides 1,755 GDD Excellent fit

Lima Beans Planting Timeline — Jefferson County, CO

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow May 21 May 21 – Jun 11
Harvest July 23 Jul 23 – Sep 3

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 Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Jefferson County

Growing Tips for Lima Beans in Jefferson County

Direct sow Lima Beans outdoors after May 14 in Jefferson County when soil has warmed and frost danger has passed.

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

Jefferson County receives only 23" of rain annually. Lima Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after soil is thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.

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 Lima Beans in Jefferson County, CO?

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

What planting zone is Jefferson County, CO?

Jefferson 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 Lima Beans in Jefferson County, CO?

In Jefferson County, CO, plant Lima 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 Jefferson County, CO for Lima Beans?

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

Can Lima Beans grow in Jefferson County's climate?

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

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson 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 Jefferson County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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