Blog

When to Plant Lima Beans in Merrimack County, NH

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.

Merrimack County, New Hampshire is in USDA Zone 5a. The average last spring frost is May 7 and the first fall frost is October 10, giving you a growing season of approximately 156 days.

At an elevation of 836 feet, Merrimack County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Lima Beans during the growing season.

Merrimack County, NH (Zone 5a) Moderate season
156 days
Last Spring Frost May 7
156 growing days
First Fall Frost October 10

Merrimack County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Aug 14
Recommended (50%) ✓ Fits season (51 days to spare)
Transplant: May 7 🍅 Harvest: Jul 9 – Aug 20
Safe Start (90%) ✓ Fits season (54 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Aug 30

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Lima Beans needs ~1,088 GDD — county provides 2,262 GDD Excellent fit

Lima Beans Planting Timeline โ€” Merrimack County, NH

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow May 14 May 14 โ€“ Jun 4
Harvest July 16 Jul 16 โ€“ Aug 27

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September โ€”
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 5a

Growing Season

156 days

Growing Tips for Merrimack 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 Merrimack County, NH?

Merrimack County is in Zone 5a with an average last frost of May 7. Plan your Lima Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Merrimack County, NH?

Merrimack County, New Hampshire is in USDA Hardiness Zone 5a. The average last spring frost is May 7 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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