Blog

When to Plant Christmas Lima Beans in Custer County, MT

Custer County, Montana Zone 4b May

Top priorities for Custer County, Montana gardeners in May

A quick May briefing for Custer County, Montana gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 14
Avg. first frost September 27
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
  1. Scatter christmas lima beans into prepared beds

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Coming up in June — start thinking about
  • Transplants going out: christmas lima beans

Instant PDF download. No spam, unsubscribe any time.

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.

Custer County, Montana is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is September 27, giving you a growing season of approximately 136 days.

At an elevation of 5,983 feet, Custer County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Christmas Lima Beans to ensure they mature before fall.

Custer County, MT (Zone 4b) Short season
136 days
Last Spring Frost May 14
136 growing days
First Fall Frost September 27

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 8 Transplant: May 31 🍅 Harvest: Aug 23 – Sep 27
Recommended (50%) ✗ May not fit
Start indoors: Mar 12 Transplant: Jun 4 🍅 Harvest: Aug 27 – Oct 1
Safe Start (90%) ✗ May not fit
Start indoors: Mar 23 Transplant: Jun 15 🍅 Harvest: Sep 7 – Oct 12

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 Custer County

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

Soil pH

Your soil pH (6.5–8.1) 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 Custer County is excellent for Christmas Lima Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). 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
0.3″/week
Watering frequency 1-2 times/week
Season total 376 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 2.2" 2.1" 💧 Light watering
Aug 4.3" 2.3" 2" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.9" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Custer 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 ~900 GDD — county provides 1,360 GDD Excellent fit

Christmas Lima Beans Planting Timeline — Custer County, MT

Christmas Lima Beans Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors June 4 Jun 4 – Jun 18
Direct Sow May 28 May 28 – Jun 18
Harvest August 27 Aug 27 – Oct 1

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Direct Sow
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October Harvest
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 4b

📆 Growing Season

136 days in Custer County

Growing Tips for Christmas Lima Beans in Custer County

Direct sow Christmas Lima Beans outdoors after May 14 in Custer 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.

Custer County receives only 24" 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 Custer County, MT?

Custer County is in Zone 4b with an average last frost of May 14. Plan your Christmas Lima Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, MT?

Custer County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is September 27.

🌱

Your Custer County Garden Planner — Free

A 24-page printable planner built for Custer County (Zone 4b). 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 Custer County, MT. 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.