When to Plant Winter Melon in Hawaii County, HI
Winter melon (wax gourd) is a large Asian squash with a waxy white coating that allows long storage. The mild flesh is used in soups and stir-fries.
Hawaii County, Hawaii is in USDA Zone 11a. The average last spring frost is January 1 and the first fall frost is December 31, giving you a growing season of approximately 364 days.
At an elevation of 525 feet, Hawaii County receives approximately 96.2 inches of rainfall annually with predominantly silty clay soil. Summer highs average 87°F, providing good warmth for Winter Melon during the growing season. Clay soil retains moisture well for Winter Melon, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Winter Melon root diseases.
Hawaii County Soil Profile
Soil Type
Silty Clay
Soil pH
5.6-6.6
Drainage
Well Drained
Plant Planting Risk Windows
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 Hawaii County
How your county's soil matches Winter Melon's growing requirements.
Soil pH
Your soil pH (5.6–6.6) overlaps with Winter Melon's range (6.0–7.0), though not a perfect match.
Soil Texture
Your silty clay soil in Hawaii County is workable for Winter Melon. Add compost annually to improve structure.
Organic Matter
Organic matter is excellent (4.1%) — Winter Melon will thrive.
How to Plant Winter Melon
Plant Water Budget
Monthly Watering Guide for Winter Melon
Winter 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 | Winter Melon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 4.3" | 13.1" | 0" | ✅ Rainfall sufficient |
| Feb | 4.3" | 11.1" | 0" | ✅ Rainfall sufficient |
| Mar | 4.3" | 11.1" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Jul | 4.3" | 2.3" | 2" | 💧 Light watering |
| Aug | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Sep | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 10.3" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 12.3" | 0" | ✅ Rainfall sufficient |
| Dec | 4.3" | 12" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Jan–Dec in Hawaii County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Winter 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.
Winter Melon Planting Timeline — Hawaii County, HI
Winter Melon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | November 20 | Nov 20 – Dec 4 |
| Transplant Outdoors | January 8 | Jan 8 – Jan 22 |
| Direct Sow | January 1 | Jan 1 – Jan 22 |
| Harvest | April 9 | Apr 9 – May 28 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | — |
| March | — |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | Start Indoors |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 11a
📆 Growing Season
364 days in Hawaii County
Growing Tips for Winter Melon in Hawaii County
With Hawaii County's clay soil (39% clay), work in 3-4 inches of compost before planting Winter Melon. Avoid tilling when soil is wet to prevent compaction.
Common pests for Winter Melon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 3-4 weeks early. Provide ample space for sprawling vines. Harvest when the waxy coating develops on the rind. Fruits can weigh 15-30 pounds.
Companion Planting
Good Companions
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Winter Melon in Other Locations
Frequently Asked Questions
When should I plant Winter Melon in Hawaii County, HI?
Hawaii County is in Zone 11a with an average last frost of January 1. Plan your Winter Melon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hawaii County, HI?
Hawaii County, Hawaii is in USDA Hardiness Zone 11a. The average last spring frost is January 1 and first fall frost is December 31.
Plan Your Garden with Confidence
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