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When to Plant Bitter Melon in Carbon County, WY

Carbon County, Wyoming Zone 5a May

Top priorities for Carbon County, Wyoming gardeners in May

Your garden in Carbon County, Wyoming is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 31
Avg. first frost September 18
Soil temp (4") 30°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
Before June arrives, get these ready
  • Transplants going out: bitter melon
  • Direct-sowing: bitter melon

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Bitter melon is a tropical vine producing warty, bitter fruits used in Asian and Indian cuisine. The intense bitterness is prized for its culinary and health properties.

Carbon County, Wyoming is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 18, giving you a growing season of approximately 110 days.

At an elevation of 8,469 feet, Carbon County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Bitter Melon to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Bitter Melon successfully. Mulch heavily to conserve soil moisture.

Carbon County, WY (Zone 5a) Short season
110 days
Last Spring Frost May 31
110 growing days
First Fall Frost September 18

Carbon County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 9 🍅 Harvest: Aug 11 – Sep 22
Recommended (50%) ✗ May not fit
Start indoors: Apr 5 Transplant: Jun 14 🍅 Harvest: Aug 16 – Sep 27
Safe Start (90%) ✗ May not fit
Start indoors: Apr 17 Transplant: Jun 26 🍅 Harvest: Aug 28 – 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 Carbon County

How your county's soil matches Bitter Melon's growing requirements.

Soil pH

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

Soil Texture

The loam soil in Carbon County is excellent for Bitter Melon — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Bitter Melon.

How to Plant Bitter Melon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Bitter Melon

2
successive plantings in your 110-day season

Sow every 6.9 weeks. Last sowing by Jun 20 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 493 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Bitter Melon

Bitter Melon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Bitter Melon Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.3" 3" 🚿 Regular watering
Aug 4.3" 1.5" 2.8" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Bitter Melon 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.

Bitter Melon needs ~750 GDD — county provides 1,100 GDD Excellent fit

Bitter Melon Planting Timeline — Carbon County, WY

Bitter Melon Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors June 14 Jun 14 – Jun 28
Direct Sow June 7 Jun 7 – Jun 28
Harvest August 16 Aug 16 – Sep 27

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May
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

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

110 days in Carbon County

Growing Tips for Bitter Melon in Carbon County

Direct sow Bitter Melon outdoors after May 31 in Carbon County when soil has warmed and frost danger has passed.

Common pests for Bitter Melon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

Carbon County receives only 15" of rain annually. Bitter Melon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 4 weeks before last frost. Provide a trellis for climbing. Harvest fruits while still green and firm. Reduce bitterness by salting sliced fruit before cooking.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bitter Melon in Carbon County, WY?

Carbon County is in Zone 5a with an average last frost of May 31. Plan your Bitter Melon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carbon County, WY?

Carbon County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 18.

🌱

Your Carbon County Garden Planner — Free

A 24-page printable planner built for Carbon County (Zone 5a). 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 Carbon County, WY. 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.