Blog

When to Plant Wax Beans in Lewis and Clark County, MT

Lewis and Clark County, Montana Zone 4b May

This month in Lewis and Clark County, Montana

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

Avg. last frost May 29
Avg. first frost September 18
Soil temp (4") 33°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
Coming up in June — start thinking about
  • Direct-sowing: wax beans

Instant PDF download. No spam, unsubscribe any time.

Wax beans are a yellow-podded variety of snap beans with a buttery, slightly sweeter flavor than green beans. They are easy to spot on the plant for picking.

Lewis and Clark County, Montana is in USDA Zone 4b. The average last spring frost is May 29 and the first fall frost is September 18, giving you a growing season of approximately 112 days.

At an elevation of 7,064 feet, Lewis and Clark County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Wax Beans to ensure they mature before fall.

Lewis and Clark County, MT (Zone 4b) Short season
112 days
Last Spring Frost May 29
112 growing days
First Fall Frost September 18
Share this guide:

Lewis and Clark County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Transplant: May 18 🍅 Harvest: Jul 13 – Sep 7
Recommended (50%) ✓ Fits season (0 days to spare)
Transplant: May 29 🍅 Harvest: Jul 24 – Sep 18
Safe Start (90%) ✗ May not fit
Transplant: Jun 19 🍅 Harvest: Aug 14 – Oct 9

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 Lewis and Clark County

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

Soil pH

Your soil pH (6.5–8.1) is more alkaline than Wax Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Wax Beans.

How to Plant Wax Beans

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

Succession Planting Wax Beans

2
successive plantings in your 112-day season

Sow every 5.7 weeks. Last sowing by Jul 15 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 200 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Wax Beans

Wax 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 Wax Beans Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.3" 2" 💧 Light watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Wax 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.

Wax Beans needs ~661 GDD — county provides 1,288 GDD Excellent fit

Wax Beans Planting Timeline — Lewis and Clark County, MT

Wax Beans Planting Calendar

Activity When Date Range
Direct Sow June 12 Jun 12 – Jul 3
Harvest August 7 Aug 7 – Oct 2

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Direct Sow
July Direct Sow
August Harvest
September Harvest
October Harvest
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

112 days in Lewis and Clark County

Growing Tips for Wax Beans in Lewis and Clark County

Direct sow Wax Beans outdoors after May 29 in Lewis and Clark County when soil has warmed and frost danger has passed.

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

Lewis and Clark County receives only 22" of rain annually. Wax Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Pick pods regularly when young and tender. Bush types produce a concentrated harvest while pole types yield longer. Avoid working around wet plants.

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 Wax Beans in Lewis and Clark County, MT?

Lewis and Clark County is in Zone 4b with an average last frost of May 29. Plan your Wax Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lewis and Clark County, MT?

Lewis and Clark County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 29 and first fall frost is September 18.

🌱

Your Lewis and Clark County Garden Planner — Free

A 24-page printable planner built for Lewis and Clark 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 Lewis and Clark 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.