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When to Plant Lima Beans in Grand County, CO

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.

Grand County, Colorado is in USDA Zone 4a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.

At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Lima Beans to ensure they mature before fall.

Grand County, CO (Zone 4a) Short season
114 days
Last Spring Frost May 28
114 growing days
First Fall Frost September 19

Grand County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Transplant: May 13 🍅 Harvest: Jul 15 – Aug 26
Recommended (50%) ✓ Fits season (9 days to spare)
Transplant: May 28 🍅 Harvest: Jul 30 – Sep 10
Safe Start (90%) ✓ Fits season (12 days to spare)
Transplant: Jun 18 🍅 Harvest: Aug 20 – Oct 1

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 587 gal / 100 sq ft
Drought risk

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

Lima Beans needs ~862 GDD — county provides 1,311 GDD Excellent fit

Lima Beans Planting Timeline โ€” Grand County, CO

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow June 11 Jun 11 โ€“ Jul 2
Harvest August 13 Aug 13 โ€“ Sep 24

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

114 days

Growing Tips for Grand County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Lima Beans in Grand County, CO?

Grand County is in Zone 4a with an average last frost of May 28. Plan your Lima Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grand County, CO?

Grand County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is May 28 and first fall frost is September 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grand County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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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 Grand County, CO. Local conditions may vary. Last updated: April 2026.