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When to Plant Christmas Lima Beans in Boundary County, ID

Boundary County, Idaho Zone 6a May

This month in Boundary County, Idaho

Your Boundary County, Idaho garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 10
Avg. first frost September 22
Soil temp (4") 44°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Set out christmas lima beans seedlings

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Seed christmas lima beans outdoors

    These tolerate cool soil, so you're not gambling by sowing now.

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Christmas lima beans are a large, beautifully marbled heirloom bean with a rich, chestnut-like flavor. They are a climbing variety that produces generously in warm weather.

Boundary County, Idaho is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is September 22, giving you a growing season of approximately 135 days.

At an elevation of 5,105 feet, Boundary County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Christmas Lima Beans during the growing season.

Boundary County, ID (Zone 6a) Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Boundary 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 (4 days to spare)
Start indoors: Mar 6 Transplant: May 15 🍅 Harvest: Aug 7 – Sep 11
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 15 Transplant: May 24 🍅 Harvest: Aug 16 – Sep 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 9 Transplant: Jun 18 🍅 Harvest: Sep 10 – Oct 15

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 Boundary County

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

Soil pH

Your soil pH (6.7–8.3) is more alkaline than Christmas Lima Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Christmas Lima Beans.

How to Plant Christmas Lima Beans

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 495 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Christmas Lima Beans

Christmas Lima 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 Christmas Lima Beans Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 2.7" 1.6" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Christmas 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.

Christmas Lima Beans needs ~1,372 GDD — county provides 2,058 GDD Excellent fit

Christmas Lima Beans Planting Timeline — Boundary County, ID

Christmas Lima Beans Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors May 24 May 24 – Jun 7
Direct Sow May 17 May 17 – Jun 7
Harvest August 16 Aug 16 – Sep 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Boundary County

Growing Tips for Christmas Lima Beans in Boundary County

Direct sow Christmas Lima Beans outdoors after May 10 in Boundary County when soil has warmed and frost danger has passed.

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

Boundary County receives only 21" of rain annually. Christmas Lima Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after soil is warm. Provide tall trellising for vigorous vines. Harvest for fresh shelling when pods are plump or allow to dry on the vine for storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Christmas Lima Beans in Boundary County, ID?

Boundary County is in Zone 6a with an average last frost of May 10. Plan your Christmas Lima Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boundary County, ID?

Boundary County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is September 22.

🌱

Your Boundary County Garden Planner — Free

A 24-page printable planner built for Boundary 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 Boundary County, ID. 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.